The Skin Longevity Breakthrough | Carolina Reis Oliveira

The skin has long been treated as a cosmetic concern, but emerging science suggests it’s much more than that. As our largest organ, the skin serves as a critical barrier between us and the outside world, yet it also plays an active role in immune function, inflammation, and healthy aging. As skin ages, the accumulation of senescent cells and declining barrier integrity may contribute not only to wrinkles and visible aging, but also to the chronic, low-grade inflammation that underlies many age-related diseases.

That’s why I was excited to welcome Carolina Reis Oliveira, PhD, CEO and co-founder of OneSkin, back to New Frontiers. Carolina has spent nearly a decade studying cellular senescence and developing interventions that target one of the fundamental hallmarks of aging.

In this conversation, we explore the science behind the OS-01 peptide, why her team screened more than 900 peptides before identifying their lead candidate, and the growing evidence that improving skin health may have effects that extend well beyond the skin itself. We also discuss biological age testing, skin barrier function, inflammation, formulation science, and why it’s time to start thinking about skincare as an evidence-based component of longevity medicine.

You’ll come away with a deeper appreciation for the skin, not simply as an aesthetic concern, but as a meaningful contributor to whole-body health and longevity.  ~DrKF

The skin is often viewed through a cosmetic lens, but emerging research suggests it may play a much larger role in healthy aging than we’ve appreciated. As our largest organ, the skin is a critical immune and barrier tissue. When its integrity declines and senescent cells accumulate, it may contribute to chronic, low-grade inflammation that extends well beyond the skin itself. This evolving science is reshaping how we think about skin health, longevity, and whole-body resilience.

In this episode of New Frontiers, Carolina Reis Oliveira, PhD, CEO and co-founder of OneSkin, shares the science behind targeting cellular senescence in the skin. We discuss why her team screened more than 900 peptides to develop OS-01, how skin-specific biological age can be measured, and the emerging evidence that improving skin health may help reduce systemic inflammation. We also explore the relationship between rapid weight loss, GLP-1 medications, and changes in skin quality; barrier function, collagen biology, topical peptide delivery, formulation science, and why evidence-based skincare deserves a place in conversations about healthy aging and longevity.

In this episode of New Frontiers, learn about:

Dr. Kara Fitzgerald: Hi, everybody. Welcome to New Frontiers in Functional Medicine, where we are interviewing the best minds in functional medicine. And of course, today is no exception. Today I am joined by Carolina Reis Oliveira, PhD, CEO and co-founder of OneSkin. She’s a longevity scientist with a PhD in stem cell biology and tissue engineering.

Dr. Kara Fitzgerald: Carolina has spent her career studying one of the fundamental hallmarks of aging, cellular senescence, and translating that science into practical applications that target aging at its source. Her team is challenging the traditional skincare paradigm by asking a much bigger and way more important question: Can improving the health of our largest organ actually influence whole-body health and longevity?

Dr. Kara Fitzgerald: In the conversation today, we explore exactly that. When OneSkin calls their product a topical supplement, today was my aha, kind of breakthrough moment where I got that yes, not only is the OS-01 peptide in OneSkin absorbed into the deep dermal layers without microneedling, etc., it’s designed to be absorbed. They’ve got evidence showing that it influences us systemically, that it can lower the systemic body burden of inflammation. This is game-changing. And as we talked about at the very end, this could really change the whole field of skincare as this idea is mined, and deepened, and broadened.

Dr. Kara Fitzgerald: In this conversation, we talk about all of their extraordinary research, from their origin story looking at senescent cells and their accumulation in the skin, and how this particular peptide very aggressively lowers them, almost more than anything else. I mean, I think it’s up there with rapamycin, but without the potential side effects of rapamycin. Extraordinary. It also repairs the barrier, stimulates collagen production, and we can go on and on and on. I want you to tune in and listen to it. You will be interested in it.

Dr. Kara Fitzgerald: And they have a hair product as well, and we talk a little bit about that at the end. I think OneSkin is really disruptive in the skincare industry and I always hand that to them because this industry has needed a serious boost. Their science, their commitment to the literature, and their commitment to making products that actually work is absolutely revolutionary.

Dr. Kara Fitzgerald: As always, Carolina, welcome back to New Frontiers. I’m a massive, massive fan and user of the full OneSkin product line. We have a lot to unpack because your team has made such a deep commitment to the science and that’s what I love to bring forward and elevate. You’re very disruptive in the skincare space. I think others will probably attempt to follow you in your commitment to science.

Dr. Kara Fitzgerald: One of the cool things is that peptides are having their big moment. They’re having a massive moment. Maybe you’re on Team Peptide, or maybe you’re kind of unsure of peptides. The criticism lodged against peptides is that there’s just not a lot of human data on them. And that’s fair. I think it’s fair.

Dr. Kara Fitzgerald: But you screened over 900 peptides before you discovered OS-01, and that forms the heart and soul of the OneSkin skincare product line. I want to talk about it. I want to talk about that journey, maybe a little background on peptides, and then we’ll dive into all the amazing science you have behind it, clinical, preclinical, and all of that.

Carolina Reis Oliveira, PhD: Yes, of course. Thanks for having me again, Dr. Kara. I think we are in a super exciting moment with this whole excitement about peptides and their potential in impacting our health in so many ways. I think, obviously, we need to be discerning about what can actually make a difference and what is hype and I think you guys, doctors, can definitely follow each intervention the best way to see how they can actually move the needle.

Carolina Reis Oliveira, PhD: But stepping back, what are peptides? Peptides are basically small chains of amino acids and they form the building blocks of proteins, and they can act as messengers. They can basically give signals to your cells to behave in a certain way. As we are seeing with GLP-1, that’s a very potent peptide, they can be very impactful. And so they can be very beneficial, but obviously, we need to tailor the dose and how it’s used on a daily basis.

Carolina Reis Oliveira, PhD: For OneSkin, when we started back in 2016—it’s been about 10 years studying skin aging, developing this whole research around peptides and cellular senescence. We basically saw that most anti-aging products on the market were not developed to target what we believe to be the key drivers of aging. If you think about the classic anti-aging ingredients, they are mostly focused on the surface of the skin, like retinoids or acids. They produce this skin renewal effect, but they are not necessarily going deeper at the cellular level and targeting what’s causing aging.

Carolina Reis Oliveira, PhD: To us, when we were studying so much about aging and seeing how much the science has evolved in the past 10 to 15 years, we knew there were new mechanisms that were being uncovered. At that time, there were the nine hallmarks of aging and now we have expanded to the twelve hallmarks of aging. For the scientific community, these were the key underlying causes of the aging process. At that time, back in 2016, no company was targeting any of these mechanisms specifically.

Carolina Reis Oliveira, PhD: There was one central mechanism that to us was really impressive, the data we had seen in the scientific community and that was the accumulation of senescent cells in our bodies. One of the most impressive data was when researchers showed two mice that were the same age, but one had its senescent cells depleted. That mouse was completely systemically rejuvenated. So this mouse was more resistant to cancer, had better metabolic health, had more fur, and could move faster. As a scientific community, we hadn’t seen an intervention that could produce this type of outcome.

Carolina Reis Oliveira, PhD: And then at that time, we saw many companies starting to target senescent cells in different parts of the body to basically address aging and prevent age-related disease. For us, it was like wow! This seemed like such an interesting opportunity to bring this to skincare and skin health.

Dr. Kara Fitzgerald: So you were reading this literature and really excited about it, of course. Did you know that the senescent cell burden in the skin was the major driver there, or did you do the research to kind of tease that out?

Carolina Reis Oliveira, PhD: Yeah, we had this hypothesis, and there was one publication sharing very interesting data. They basically recruited over 170 participants and they had their perceived age evaluated by a group of people, they measured their comorbidities—what types of chronic diseases those participants had—and then collected biopsies and measured the load of senescent cells.

Carolina Reis Oliveira, PhD: What they found from that study is that people who had a higher perceived age compared to their chronological age frequently had more comorbidities and were correlated with a higher load of senescent cells.

Carolina Reis Oliveira, PhD: This was a very interesting study to show that if you have more senescent cells in your skin, your skin can appear older than your chronological age. And it can also have more systemic implications, meaning that the skin can be a biomarker of your systemic health because these participants also had other comorbidities.

Dr. Kara Fitzgerald: That’s so fascinating. I’ve mentioned research, and I think we’ve dialogued about it, where we’re able to discern people’s well-being by looking at their skin. So people who actually look older—and a piece of that is this accumulated senescent cell burden in their skin, that’s a pro-aging phenomenon. They actually are biologically older. I think it’s fascinating that we have the ability to discern that. In my own little world, I think maybe it has something to do with evolution and who we want to surround ourselves with, the strongest, the people who are going to survive.

Dr. Kara Fitzgerald: Can you just describe—I think most of the audience are pretty savvy clinicians tuning in here—but give us a little background on why we care about senescent cells, sometimes referred to as zombie cells, and why they’re so damaging.

Carolina Reis Oliveira, PhD: Yes. So what are these senescent, or as you said, zombie cells? These are essentially damaged cells that become dysfunctional with the aging process. So these are cells that have either divided too many times and accumulated mutations. This is actually a protective mechanism of our body. If these cells are too mutated, they shouldn’t divide anymore. So we’re going to pull the trigger, and they’re going to stop dividing.

Carolina Reis Oliveira, PhD: The main problem is that these cells can also start secreting inflammation. We call this SASP, the Senescence-Associated Secretory Phenotype. This inflammation can induce other cells around them to become senescent or to age faster. We usually compare them to a rotten fruit, like a rotten orange in a basket. When one fruit starts to get moldy, the fruits around it start to deteriorate. That’s what the accumulation of senescent cells is causing in our bodies.

Carolina Reis Oliveira, PhD: This happens in different tissues throughout our bodies, and the accumulation of these cells is associated with several age-related diseases. In the skin, what happens is that as the cells accumulate, they secrete more inflammation. This leads to collagen degradation. It’s going to compromise the barrier of the skin because there is more inflammation in the skin. And so basically, there is this accelerated aging process that happens with the accumulation of these cells.

Carolina Reis Oliveira, PhD: What’s interesting is that these cells are basically formed throughout our lives. When we are young, our immune system is really good at clearing out those cells, so it’s a constant surveillance process. But as we grow older, our immune system also becomes less efficient, and these cells start to build up. That buildup leads to more inflammation, which basically overwhelms our immune system. It can’t do its job properly and that’s when we need interventions that can help our skin and our body lower that inflammation so our immune system can do its job again. Once we have that inflammation lowered, or if we can reduce the load of senescent cells, the immune system can clear out the senescent cells that are already there.

Dr. Kara Fitzgerald: That’s so interesting. I have a flood of questions, and we’re going to talk about what you discovered the OS-01 peptide does with regard to these guys. But before we jump into that, I want to talk to you about lifestyle influences on senescent burden as well. But let’s just talk about epigenetic clocks first and how we’re using those more broadly in clinical practice, but also how you specifically figured out how to measure the aging phenomenon in skin.

Carolina Reis Oliveira, PhD: Yeah. Once we saw, okay, there is this hypothesis that if we can reduce the number of senescent cells in the skin, we can actually bring the skin to a biologically younger state, we had two tasks at hand. One was how we were going to target senescent cells and reduce them. That’s when we started the peptide research and screening. As you said, we spent over five years screening hundreds of peptides, and eventually we landed on OS-01. That’s the peptide behind all of our products and it can basically reduce the level of senescent cells from 20% to 50% in our studies. As I said, it really shuts down inflammation, helps your skin cells replicate again, produce collagen, restore the barrier, and bring the skin to that younger state.

Carolina Reis Oliveira, PhD: To measure senescent cells, we use different biomarkers in the lab. We can stain those cells, we can quantify their number, and basically prove that this peptide is actually lowering the load of senescent cells. But then we also wanted to measure what that means in terms of biological age. How is this peptide actually shifting the biological age of the skin?

Carolina Reis Oliveira, PhD: As you mentioned, there were epigenetic clocks available at that time, but there were no clocks that were specific for skin age. The closest clock available was one from Dr. Horvath that focused on skin and blood. So we decided to build a clock that was trained only using skin samples in order to increase the accuracy of our measurements.

Carolina Reis Oliveira, PhD: One of my co-founders, Dr. Mariana Boroni,  is actually a bioinformatician, and she built this MolClock. We used public data that was available, over 500 skin samples ranging from 20 years old to 80 years old. Basically, she measured how the epigenetics changed with the aging process, and this gave us a way to measure the biological age of the skin. And then once we had the peptide and treated the skin with it, we could measure how many years, biologically speaking, we were shifting the age of the skin.

Carolina Reis Oliveira, PhD: We published that clock back in 2020, so it’s been almost six years. We also published data showing that our peptide could reduce the age of the skin we treated in the lab by 2.5 years using this clock that we developed. We used this for our research and validation process. We don’t continue to use this clock anymore. We actually partner with other companies now to measure how these interventions can change biological age in humans, which we can discuss as well.

Dr. Kara Fitzgerald: Yeah, and we’ll stay tuned because I know we were dialoguing off-air about the potential for a clock becoming available to us as clinicians at some point to measure skin and I think it could be highly motivating, and I’m glad that is being worked on. But this is a biopsy and obviously we’re not going to be regularly taking skin biopsies on our patients. It’s a little too invasive but of course, you’re going to be doing that in the research setting. So bravo to you and your team of amazing PhD women for answering these questions one after another.

Dr. Kara Fitzgerald: When you formed a hypothesis, you just went in there and answered it. I know that you have a very active lab at OneSkin, and you continue to drill down into all of these extraordinary questions. I just want to say, wow, what else drops the senescent cell burden by up to 50%? What other intervention? Seriously. What do you know? That’s massive drop.

Carolina Reis Oliveira, PhD: Yeah. To be completely honest, it varies. It varies from 20% to 50%. But when we were screening and saw that data, we were like, wow, this could be huge because it’s really hard to find this kind of impact in cells.

Carolina Reis Oliveira, PhD: Just for comparison, we’ve measured a very potent flavonoid, fisetin, and with fisetin we saw about a 20% reduction. We’ve measured NMN, (Nicotinamide Mononucleotide) and NMN can also reduce senescent cells by about 10% to 20%. Then there are things like metformin, which are a little lower. Interestingly enough, we always use rapamycin as a control. Our peptide very often compares to the rapamycin effect in terms of reducing senescence, but without the potential side effects or immune compromise that can happen with rapamycin. We’ve tested several molecules that are being studied to reduce senescent cells, and it’s really exciting to see that our peptide compares with the most effective ones that we have found.

Dr. Kara Fitzgerald: It’s just so cool, Carolina. It’s so cool. What was the duration of the intervention that showed the 2.5-year age reversal? How long were you applying the OS-01?

Carolina Reis Oliveira, PhD: Yeah, because this was an in vitro lab experiment, it was over five days.

Dr. Kara Fitzgerald: Five days?

Carolina Reis Oliveira, PhD: I know, it’s a very short time, but obviously we can’t necessarily extrapolate that. We actually did one pilot clinical study in humans where we followed participants for 12 months. We collected biopsies and saw a reduction of 3.3 years over 12 months. I would say that’s a more realistic expectation of what we would see in human skin because, in the lab, you have ideal conditions so you can get amplified results. But it’s a great proof of concept.

Carolina Reis Oliveira, PhD: Our goal was to determine whether it was actually possible to reduce the biological age of the skin. Our finding was yes, we can do that and now, what we’ve been doing with our products is translating that into a benefit that people can  have when using them.

Dr. Kara Fitzgerald: Well, we make a commitment to using skincare. We use it daily, at least once a day, probably most… It’s not a heavy lift. It’s not like an exercise routine. It’s not like you’re lifting kettlebells in the gym. It’s really easy to apply this, and to see that benefit is quite cool.

Carolina Reis Oliveira, PhD: We usually compare our products to a topical supplement. Similar to how we cannot get all the nutrients that we need through our diet, so we take supplements. This is like a supplement for your skin. That’s how you’re going to provide what your skin may be missing or what it may be losing with the aging process with all the stressors we’re exposed to on a daily basis.

Dr. Kara Fitzgerald: Yeah, relentless exposure to the sun, to toxins. Of course. I mean, it is the largest organ. It’s the interface between what’s out there and what’s internal. I want to say that people are listening and they hear this up to 50% reduction in senescent burden, and they’re thinking, “Okay, I’m just going to take this internally.” So I always ask you about that. When might you consider moving in this direction? But I know you’re very committed to putting this into skin products, understandably so. As you’ve shown in your research—and I want you to talk about this—you can actually exert a systemic effect by using it topically.

Carolina Reis Oliveira, PhD: Yes.

Dr. Kara Fitzgerald: I want you to talk about what you’ve shown, and I also want to throw out there for the clinicians that barrier repair, improving barrier patency, is no small deal. We’ve talked about favorably shifting the microbiome, rebuilding and restoring the skin.  Yes, reducing senescent cells, but so much more than that. And indeed, you’ve demonstrated and published peer-reviewed literature on a systemic influence using that delivery avenue as the skin. So talk about that.

Carolina Reis Oliveira, PhD: Yeah, that was one of the most exciting studies that we’ve done because when we started this company, we were always very passionate about human health and longevity, and we saw that the skin was the missing piece in this longevity conversation. We know that the skin is our largest organ and it’s intended to be this barrier of protection.

Carolina Reis Oliveira, PhD: What we didn’t realize when we started was that as your skin ages and accumulates more senescent cells, and as you said, as the skin barrier weakens, this can become a source of inflammation, and even low levels of inflammation can eventually impact our internal health. An interesting fact is that people with psoriasis have around a 50% higher chance of developing cardiovascular disease if their lesions are not treated. If their psoriasis is controlled, I don’t think they have this problem. But if they’re constantly flaring, that inflammation that’s coming from the skin impacts internal health. Cardiovascular disease is one area where this has already been validated.

Carolina Reis Oliveira, PhD: What happens with skin aging is a similar process, but the inflammation is lower grade. It affects all of us. If we’re not treating our skin and maintaining a strong skin barrier, our skin will start to deteriorate. We’ll become more susceptible to pathogens and environmental stressors, and that low level of inflammation can eventually impact our internal health.

Carolina Reis Oliveira, PhD: In our study, we recruited participants between 60 and 85 years old, so their skin was already more compromised and fragile. We collected their blood at baseline, then they used our face and body lotion twice a day for three months, and then we collected their blood again. We measured several parameters related to skin quality, and we had a control group using another product based only on emollients and more focused on hydration.

Carolina Reis Oliveira, PhD: The control group did not see the same improvements in terms of hydration or barrier function. We saw around a 40% increase in hydration and barrier function and over 70% of our participants saw improvements in overall skin quality.

Carolina Reis Oliveira, PhD: The most interesting part is that when we evaluated their blood and measured their inflammatory profile, we saw a decrease in several markers associated with inflammation and a significant drop in interleukin-8, a well-known pro-inflammatory marker. And again, the main intervention these participants underwent was using this product. They continued with the same lifestyle.

Carolina Reis Oliveira, PhD: So compared to the control, the control did not decrease. Actually, some of the markers were increased in control, and the OneSkin group showed decrease in most markers and a significant decrease in IL-8. So this was really exciting to show, that a topical intervention can help reduce inflammation systemically.

Dr. Kara Fitzgerald: Exactly. Right. And that’s just over three months. So if you develop the habit and your using it… Yeah, I’m just thinking about how I prescribe it in my patient population. It’s really well tolerated. I don’t think I’ve had a negative report. I work with some very sensitive patients, people who have really difficult eczema that’s hard to treat and very refractory. They might have a filaggrin mutation. And it’s because I’m on faculty at IFM and teach in the immune module, so I’ve had many referrals involving allergies and skin conditions. Of course, atopic dermatitis is a huge one.

Dr. Kara Fitzgerald: Actually, even before we started using OneSkin, we had actually developed our own recipe for our most sensitive patients go and make a product so they could tolerate it. But you know what’s fascinating is that those products, while soothing and it can feel good, it’s like your control product. So it feels good, and maybe you look better and feel better, but you’re not necessarily repairing the barrier. So that addition of OS-01 is incredible because of course, all of these skin conditions share barrier permeability, without question. And we know that influences systemic health. I think that’s been pretty potently demonstrated.

Dr. Kara Fitzgerald: And the longer you have a compromised barrier, the more you’re driving not just local inflammation but potentially systemic inflammation. So we use it, and I know you haven’t moved into researching the OS-01 peptide in skin conditions, but certainly clinically I can report, and I know you’ve heard many of these reports as well. Any comments on that? And then I want to talk to you about a broader lifestyle approach with it.

Carolina Reis Oliveira, PhD: Yeah, I think it’s great to hear that. Anecdotally, we see a lot of our customers sharing that by helping to repair their skin barrier, they can minimize or overcome some of these skin conditions. And I think the other very important piece that you mentioned is that we’re very thoughtful with our formulations. So safety, and avoiding toxicity, irritation, or sensitization, is really top of mind for us because, as you said, many of these patients have very sensitive or fragile skin.

Carolina Reis Oliveira, PhD: So first of all, when formulating, we avoid fragrance, essential oils, and obviously our products are also tested to ensure they do not contain heavy metals or contaminants. When we test them on skin, we can clearly see that the formulas are not compromising the skin in any way. They’re not inducing cells to behave in an unexpected way.

Carolina Reis Oliveira, PhD: And we have tested a lot of products that we see that can cause some type of irritation or toxicity so I think that’s very important to share because I know your community cares a lot about safety and not having ingredients that could potentially cause more irritation or sensitization in the skin.

Dr. Kara Fitzgerald: Yeah, it just makes me think, we’ve had this conversation, or a similar conversation in this particular area, and we’ve dove a little deeper, so we’re going to link to our other conversations in the show notes, folks. We’ll also corral together all of the papers that Carolina is referring to and we’ll make sure you have links to all of those as well, so you can pull up the full texts.

Dr. Kara Fitzgerald: I always refer to you lovingly as being really disruptive and I think the skincare industry really needs a hardcore shakeup. We’ve been paying a lot of money for very sexy-packaged products that feel good. It’s like your control product. It felt great on the skin, right? And it did nothing. It did nothing. In fact, as you said, their inflammatory markers actually got a little bit worse. It’s crazy.

Dr. Kara Fitzgerald: We’ve all just bought this bill of goods and if there is research conducted, it’s always subjective, which isn’t terrible. I think it’s reasonable to ask, “Do you think you look better?” and they’ll show some subjective improvement. But as far as doing the hardcore science behind what is it doing, what are you using, and how it’s influencing it, you know, we’ve just been sold this hardcore bill of goods and that is the anti-aging skincare industry.

Dr. Kara Fitzgerald: We’ve dialogued off-air about how longevity medicine has completely ignored paying attention to the skin, which strikes me as really odd. And then we’ve got the aesthetics industry paying a whole lot of attention to the skin, but really doing nothing. So I just wanted to throw that out and kind of get your thoughts.

Carolina Reis Oliveira, PhD: Yeah, it’s really hard to say that none of the products out there necessarily work. I don’t want to do that. But I think what we’ve found in our research that very few companies do, is something that’s really important, and that’s testing the final formula. Because what the industry mostly does today is get ingredient information from their supplier, and they mix those ingredients into one formula, and as you said, if they do consumer or clinical studies, that’s already a really good step. Some companies don’t even do that.

Carolina Reis Oliveira, PhD: But what we’ve found is that when you combine those ingredients, depending on the dose and concentration, you don’t know the final outcome until you test it on skin models in the lab and you can visually see how it impacts the skin, or how it’s impacting inflammation markers. And so, where we’d like to see the industry going is testing final formulations in vitro, in the lab, to make sure that at the cellular level, we don’t see any signs of toxicity. Then we can go to human studies, because as you said, a product can feel good and have a nice texture, but at the cellular level, you may not see what’s going on.

Carolina Reis Oliveira, PhD: And I don’t want to promote fear in any way, but that’s one area where we’d love to see the industry evolving. Because we do see that even when you add too many bioactives in one formula, it’s just not that good. Sometimes we have tested combining different peptides with OS-01, or even increasing the dose of OS-01 itself, and it’s not necessarily better. So that fine-tuning and being able to measure how the final formulation is performing, I think is very important. It’s one area where we feel very proud of the investment we’ve made, and we’d love to see more brands investing in that.

Dr. Kara Fitzgerald: So there’s a synergistic interaction. Maybe the sum is greater than the individual parts.

Carolina Reis Oliveira, PhD: Most of the time, it’s not. That’s the thing. Most of the time, what we think is synergistic is not. One plus one doesn’t always equal two, or three, or four. Sometimes it equals one and a half, or even one.

Dr. Kara Fitzgerald: Right.

Carolina Reis Oliveira, PhD: That’s the tricky part and that’s what we’ve in supplements as well. There are papers showing that if you combine too many different supplements without being thoughtful about it, you may not get the synergistic benefit you’re hoping for.

Dr. Kara Fitzgerald: I want to come hang out at your lab one day. I really would like to. It would be fun. Bravo for doing all of that work. I’m just thinking too… I mean, maybe I could be a little more plain spoken around the industry. And I appreciate you being diplomatic, but there are a lot of products out there that we spend a lot of money on that are clean. They’re clean so we’re advising our patients to use them because they’re clean and demonstrated not to contain certain things, which is a step in the right direction. But to your point, if it doesn’t go past that, it’s just another feel-good product that really isn’t going to do anything.

Carolina Reis Oliveira, PhD: Yeah. And that’s why I recommend going to the brand and asking for the studies they’ve done. Ideally, they should have done in vitro studies, clinical studies, and published research in peer-reviewed journals. All of those steps show credibility and how much a brand is investing in validating both efficacy and safety of that product.

Carolina Reis Oliveira, PhD: So that’s what I recommend. Just ask them, what kinds of tests have you done and are there independent third parties that have evaluated your product for safety and efficacy?

Dr. Kara Fitzgerald: Yes. Absolutely. I think that’s reasonable. We do that, or at least some of us do, in the realm of supplements. We’ll ask for quality-control data and we’ll look at the literature on what we’re prescribing, and so forth. And yeah, I think we need to apply that same lens to skincare.

Dr. Kara Fitzgerald: We know that just by using the OS-01 peptide in OneSkin, just in three months you’ve demonstrated reversal in bioage, you’re able to show a drop in senescent cells, and a drop in inflammation. What if we layer on a full functional medicine approach? What if we layer on adequate hydration, changing dietary pattern, moving the body, and maybe an appropriately designed supplement cocktail, or something like that? We could do a lot. I want you to speak to what you know in that arena, using a full systems/functional approach.

Carolina Reis Oliveira, PhD: Yes, one hundred percent. I think that skin is one piece of the puzzle, but if you are just taking care of your skin and if you’re not taking care of your diet, and if you’re having a high-inflammatory, high processed-food, high-sugar diet, that’s going to impact your skin. If you’re handling a lot of stress on a daily basis, that’s going to impact your skin. We know alcohol consumption, we don’t sleep well, we are dehydrated, you look way older the next day. Pollution… There are so many things that are directly related. Our nutrition, what kind of water intake, and all the antioxidants and all these nutrients that are important, like vitamin C, vitamin A, vitamin E.

Carolina Reis Oliveira, PhD: These are all essential components in a way that helps our overall health and helps our skin. So I usually say that’s a two-way approach. It’s inside out and it’s outside in.

Dr. Kara Fitzgerald: Good. Yeah. Amen. I don’t think you’ll get any pushback on that here. What about delivery of OneSkin? Different concentrations? You came out with a lip product, which I absolutely love. We could talk about that. You have the eye-specific formula, and you have the hair serum now as well. Do you recommend using OneSkin before and after microneedling? Or have you thought about it in relation to lasers, et cetera, and some of the tools that are being routinely used?

Carolina Reis Oliveira, PhD: Yeah, that’s a great question. So two things. I think OneSkin is really helpful before doing any kind of more aggressive treatments. One, because you’re going to strengthen your skin, you’re going to make your skin more resilient. And whenever you do some kind of laser or microneedling, you are going to see your skin bouncing back from that insult faster. So you’re able to recover faster, you’re able to have less inflammation. So a prep with OneSkin for a few months, we see a lot of customers reporting that, and I can attest to that myself.

Carolina Reis Oliveira, PhD: And then once you do microneedling or something where you have open wounds, we don’t necessarily suggest that you apply OneSkin right on top. But as soon as the wound is closed, then it’s going to really help you recover that healing process. So it helps after the microneedling or the laser, with the downtime, to reduce the inflammation, to reduce the redness, and help your skin recover faster. So it’s a great, I would say, adjacent product to some of those interventions.

Carolina Reis Oliveira, PhD: In terms of the delivery on intact skin, what we have tested many, many times in the lab is that the peptide can penetrate because we designed the formula with some ingredients that simulates the skin structure. So it allows the peptide to go through the stratum corneum and get to the epidermis and the dermal layer. So we measure this in our lab, that the peptide actually gets to the dermal layer, which is the layer with the fibroblasts that you want to produce more collagen. So it does penetrate with intact skin and as I said, after microneedling or after laser, if it’s not causing any wounds, you can totally use it too.

Dr. Kara Fitzgerald: I have some of the eye cream, and I love it and I use it here, but also sometimes I’ll use it on other areas that I’m not super happy with, like maybe around my lips or whatever. I’m in such intense sun here where I am in Mexico. I’ll use a little extra on my cheeks, the areas that kind of get ruddy from just being sun exposed despite layers and layers of sunscreen. Is that fair, to use a little extra there?

Carolina Reis Oliveira, PhD: The eye cream is the most potent formula that we have developed. It has the highest concentration of the peptide. And we were able, as I said, to increase the concentration and actually deliver a better outcome because we tried this with the face product and it didn’t necessarily work.

Carolina Reis Oliveira, PhD: So depending on the combination of the other ingredients, in this case testing on the specific skin around the eye. We actually get skin from blepharoplasty surgery, so we are actually treating the eyelid skin in the lab, which is very sensitive and delicate. And so you want to make sure that this is a more potent formula, it has more active ingredients, and is not going to cause irritation or burning.

Carolina Reis Oliveira, PhD: So we saw that this product was able to increase collagen 130% more than our face product. It actually reduced the aging markers that we measure in a more significant way. So similar to you, what I do is I apply around my eyes and over the eyelids. And from the clinical study, we actually saw the strongest clinical data as well. We saw smoothing of the lines or wrinkles on your eyelids and around your eyes. And we saw a really strong increase in hydration and elasticity measured by instruments.

Carolina Reis Oliveira, PhD: We usually like the instrument measurements the most because they are the most accurate and reliable ones. So I apply around my eyes, and then I apply around my mouth lines and if I have some lines on my forehead, any target areas. Sometimes I put it on my neck. There are a lot of customers that put it on their neck. It’s one that you can be more targeted with, depending on the area that you want to improve the most.

Dr. Kara Fitzgerald: Awesome. Awesome. But there’s not necessarily a net benefit to take the eye cream and slather it all over your body. I know some people are probably thinking about it, but just a little targeted use. Yeah. Yeah.

Dr. Kara Fitzgerald: Combination-wise, are there any other skin interventions? I think there are some people who are going to use retinol. I had a pretty harsh experience and I haven’t… Sometimes I’ll use a little bit of it, but I go very gentle with it. But you can use this as kind of healing if you are somebody who’s going to be using retinols. Do you want to speak to that?

Carolina Reis Oliveira, PhD: I love that question. So basically, retinols are very potent, and some people can tolerate them very well, but a lot of people cannot. So that’s another area where our product, in combination with retinol, can be very helpful. Retinol can cause more inflammation, and we have seen this in the lab many ways because it’s causing this cell renewal process. Your upper layers of skin are coming out, you’re growing newer skin, but in this process a lot of people can get irritation.

Carolina Reis Oliveira, PhD: So if you use our product in conjunction with retinol, you can tolerate it better and you can even reduce the potential irritation. So what I usually recommend, if you are someone that has more sensitivity to retinol, you can apply OneSkin first and then apply retinol on top. If you’re someone that already tolerates retinol well, you can apply retinol first and then OneSkin on top. And it will also help counteract some of those side effects of retinol.

Carolina Reis Oliveira, PhD:  And I was going to say, we actually developed something around that that I’m excited to share with you, but it’s still a few months away from coming out. But we want to make sure that we are addressing some of those drawbacks of retinol while it still delivers the benefits.

Dr. Kara Fitzgerald: Okay, cool. Well, I’ll bug you about that. I just want to say again, being here in Mexico, I use a lot of sunscreen. The Spanish word is coming into my head. I use a lot, lot, a lot of your sunscreen. And it’s not lost on me that it’s not just blocking the sun. The OS-01 is there and I’m actually nourishing my skin as well as blocking some of the damage from the sun. And I know that’s—

Carolina Reis Oliveira, PhD: On the sunscreen, what I would say is it also has five very potent antioxidants. We have a very stable form of vitamin C, we have green tea, we have acai extract. So this can replace your vitamin C serum. It’s a way that you can simplify your skincare routine. For me, I like to be very practical. I’m sure you do as well. I  don’t have much time or patience so I only use the moisturizer and then I use the sunscreen that already gives me the vitamin C and the peptide. The moisturizer also has the peptide. And at night I use the moisturizer and the eye cream and the body lotion after I shower.

Carolina Reis Oliveira, PhD:  So we like to make it simple and easy. I will use retinol from time to time, and that’s basically it. I think we are covering, with the peptides, antioxidants, ceramides—we have ceramides in our body lotion that really help with the barrier of the skin—and all the key ingredients, hydration. We have three types of hyaluronic acid in our face moisturizer that again help with hydration. So you’re basically putting all the key pieces that your skin would need to have the healthiest skin that you could have.

Dr. Kara Fitzgerald: And just aesthetically, I’ll throw this out, the tinted face sunscreen has completely taken over any makeup I would be using. That’s it. I’m not using blush. I’m not—

Carolina Reis Oliveira, PhD: Yes, same. Foundation, right? Exactly. It gives you a little bit of glow and then you put, I don’t know, maybe a little blush and you’re good to go. Yes.

Dr. Kara Fitzgerald: Yes. I want folks listening to know that we’ve had these conversations, and some ears perked up when I mentioned their hair product. We’ll link to that podcast as well. So if you’re interested in learning about that, please circle over there because, of course, it’s very, very cool.

Dr. Kara Fitzgerald:  Listen to the whole podcast on the hair and you can hear all of the research. But one of the cool things is that you do actually want it to be absorbed a little bit deeper. And so even though you’re not applying OneSkin directly to a microneedled face or concurrent with a microneedling process, with the hair you’re using sort of a little microneedling-type device to allow the serum to absorb.

Carolina Reis Oliveira, PhD: Yeah, that’s a great point because the hair formula is a water-based formula so we have a dermaroller that you can apply to your scalp in the areas that you want the product to penetrate better. And that product is completely suitable to be applied after those microfractures that you are creating in the scalp because that will actually help the serum penetrate better and can improve the efficacy of the product. So for the hair, it’s totally fine to do the dermaroller and then apply the serum right after.

Dr. Kara Fitzgerald: Okay. That’s fabulous. And give me like a thirty-second overview of the data, because we’re linking to it in the show notes, folks.

Carolina Reis Oliveira, PhD: So we had this hypothesis that the scalp is a continuation of your skin. And as senescent cells accumulate in the hair follicle and produce inflammation, this could be a contributing factor to hair thinning and hair loss. And primarily one type of hair loss that’s called age-related hair loss, or hair thinning, that affects most people after the age of 50 or 60. We are all going to see that we’re going to have less hair on our heads than when we were in our twenties.

Carolina Reis Oliveira, PhD: And so I think there are two pieces that are important to share here. One is that the same way that we are treating our skin to prevent wrinkles, why are we not treating our scalp to prevent hair thinning and hair loss? Most of the time we’re only going to treat our scalp when we’re already losing a lot of hair, and then it’s always harder to reverse, although it is possible.

Carolina Reis Oliveira, PhD: So we developed this hair serum, and again, designed it for age-related hair thinning and we saw in our studies that it actually helps increase hair density and hair thickness by about 30 to 40 percent. So really, really strong and encouraging data. It does take time, so I’ll warn everyone that you should be consistent, ideally use it once a day at least, if you can twice a day, for three to six months to see the results. I’ve been using it myself. I have so much baby hair. Look at this baby hair. And I’m someone that experienced hair thinning. I can’t take minoxidil right now because I’m still in my fertility phase.

Carolina Reis Oliveira, PhD: So this is a safe formula that you can use if you’re postpartum or at any time in your life, and for women that are going through menopause and losing a lot of hair. So it’s an incredible product that we’re excited about as well.

Dr. Kara Fitzgerald: Fabulous. You know, we were together in LA not too long ago, and you and I spoke offline—maybe we actually spoke about it on stage—that you’re thinking about how the OS-01 peptide in OneSkin might be useful in some of the challenges, some of the accelerated facial aging with the GLP-1s. And I wanted to see what comments you have on that. We started that conversation, and I think it’s an area of active investigation for you right now.

Carolina Reis Oliveira, PhD: Yes, that’s one area that we’re very excited about. And that came initially from a lot of our customers reporting that they saw many benefits if they were losing weight, in helping with skin tightening and reducing sagging. And then we started to study it internally and we’re measuring whether GLP-1 agonists actually directly impact the skin. And we haven’t found a direct impact of GLP-1s on the skin.

Carolina Reis Oliveira, PhD: But we know that under the skin there is a layer of adipose stem cells and if you have a rapid loss of weight, you can reduce that layer of adipose stem cells. And that gives not only very protective, anti-inflammatory factors for the skin, but you also lose the structure, right? So your skin that was before sitting on top of that layer is now dropping. And that lack of structure also leads to changes in the matrix of the skin.

Carolina Reis Oliveira, PhD: So what we have seen anecdotally, and now we are studying in a clinical trial, is that if we start using OneSkin while using GLP-1s, and hopefully you’re not losing weight too fast, and hopefully you are still having proper nutrition and exercise, you can minimize some of those effects on quality of the skin. Because if you lose too fast, you’re going to see a very significant impact on the quality of the skin. And our hope is that we can minimize some of those effects.

Carolina Reis Oliveira, PhD: So we’re starting a study right now. It’s going to be a study that we’re going to run with patients that are already using GLP-1s and are more in the stable phase. And we’re going to measure the impact on the skin using our products during this phase. From our internal studies, we already know that the body lotion helps strengthen the barrier of the skin and helps with collagen production. So we know that it’s already providing those building blocks that you may be losing during this process of weight loss, and so maintaining skin quality during this process is really important.

Carolina Reis Oliveira, PhD: So more to come, but it’s very promising and very interesting to see how GLP-1s can obviously be very beneficial in many ways and reduce overall inflammation. But if you lose that adipose layer under your skin too fast, you may also be losing some of those protective factors. So that’s where we want to come in and replace them.

Dr. Kara Fitzgerald: Awesome. That’s awesome. That’s fabulous. Yeah. It seems to me that it’s hard to avoid some of that accelerated facial aging when you use GLP-1s so I’m glad you’re looking at it. I’ll be super curious what you find in your clinical work.

Dr. Kara Fitzgerald:  So when we were on-site together, there was a woman in the audience. She was clinically trained, I think she might have been a nurse, but she was taking care of women post-C-section and helping them with scarring and so forth. And she was seeing nice results with OneSkin, which I thought was really cool. Specifically with the body lotion. I was like, well, would you use the eye lotion? And I think you said no, just stick with the body lotion, that it was appropriate. Do you want speak to that and actually using it in scar tissue?

Carolina Reis Oliveira, PhD: Yeah, so scar formation is a very interesting process because when you have a wound, senescent cells are actually important to help close the wound. The senescent cells will basically recruit immune cells that will help close that wound. So it’s very important to trigger that process, but you don’t want to have persistent senescent cells there because if they continue to secrete inflammation, they can impair the remodeling of the matrix. So you can have more deposits of collagen than you want, so you can have fibrosis.

Carolina Reis Oliveira, PhD: So right after you close the wound, applying our products can help with having a smoother matrix deposition by modulating the senescent cell factor secretion.  And we have heard this many, many times from our customers. So that’s one thing. Again, we have not developed a product specifically for that, but hypothetically and scientifically speaking, it would make sense that by controlling the amount of senescent cells in scar formation, it could help minimize scarring and irritation and support the natural recovery process.

Dr. Kara Fitzgerald: Super interesting. So senescent cells are essential in driving that acute inflammatory process that allows the wound to be healed. But if it keeps going, then you’re going to be vulnerable to the scarring and the keloids and just an increased burden of senescent cells that you don’t want. So then moving in with OneSkin can help turn the volume down on that.

Carolina Reis Oliveira, PhD: Yeah. And another interesting anecdotal report, we saw people that had difficulties with wound closure, and in this case they are more diabetic patients. They applied OneSkin around the wound and that helped close the wound too. So that was another very interesting observation. And in that case, the wound was not closing because there was already so much inflammation going on. We know that in diabetic patients, so in some of those cases, if you have a persistent wound, you can also try to see if that can help close the wound. Don’t ever apply it straight on the wound, just around the skin, because by supporting the skin around it, you get that effect.

Dr. Kara Fitzgerald: And as you said earlier, you’ve tested the absorption and it goes right down into the deeper dermal layers, right?

Carolina Reis Oliveira, PhD: Yeah.

Dr. Kara Fitzgerald: That’s very cool. Okay, so the industry, I think, is changing. As you suggested, I think that you’ve been leaders in disrupting the skincare industry and forcing it forward into really bringing good, solid science in. How do you project the industry in the years to come? Like, the whole science of skincare, and how will you be involved in that?

Carolina Reis Oliveira, PhD: I think one of the areas that we’re seeing that’s already emerging is basically skincare, skin health, and longevity. And I think it makes so much sense that we are now talking about skin in that context as well, and that we are thinking about longevity and overall health when we are formulating our products. Because before it was, okay, I want to formulate a product to look better. Now I want to formulate a product to increase my skin barrier, my skin resilience, and then, as a consequence, I will look better, which is amazing.

Carolina Reis Oliveira, PhD: So I’m excited to be more precise in how we are addressing aging and even the combinations of ingredients that can be most beneficial to our skin from a functional standpoint instead of just aesthetics. I think peptides and understanding all of these aging pathways and how we can intervene and measure them. This is one area.

Carolina Reis Oliveira, PhD: And the other area that we talked a little bit about is really starting to use, or see, the skin as a biomarker for internal health because I think in the end, the skin is a more accessible tissue. And if we can correlate some of those skin changes and biomarkers with what’s going on internally, I think this will be a very interesting way to tap into the skin more as a way to understand what’s going on internally. So these are two areas that we are working on and excited to see what we can bring next to our community.

Dr. Kara Fitzgerald: It would be so extraordinary to use—I mean, we already are because your data shows that you drop systemic inflammation—but really, very intentionally apply something on the skin, and okay, it’s going to act locally and do all these fabulous things, but I am going to make a difference internally. And you’re in that now. This is an epiphany happening right now. I’m just getting that. It’s amazing.

Carolina Reis Oliveira, PhD: Or also, as that study with senescent cells showed, okay, even before I take a product, if I take a piece of my skin and it has more inflammation, or more senescent cells, is that a sign that I may have some comorbidities that I don’t know about? So I need to then evaluate my whole internal health. So I think it would be very cool to see how those biomarkers in the skin correlate with your internal health. And then obviously you should treat your skin, but you should treat your internal body too.

Dr. Kara Fitzgerald: Of course. Of course. Well, very exciting conversation. Carolina, thanks for joining me again. It’s always great to talk to you and hear what you are up to over there at OneSkin. Thanks so much.

Carolina Reis Oliveira, PhD: Of course. Thanks for having me.

Dr. Kara Fitzgerald: I hope that you loved that conversation with Carolina Reis Oliveira as much as I did. Is she not the coolest? I mean, her and her team are really committing to the deeper science.

Dr. Kara Fitzgerald: And I really enjoyed our dive into looking at GLP-1s and accelerated facial aging. She talks about the mechanism behind that and their investigation. They’re launching a clinical study into seeing how the OS-01 peptide might influence that journey, i.e., how these OneSkin products might actually help when an individual is using a GLP-1.

Dr. Kara Fitzgerald: And then, of course, we talked about the barrier. We talked about systemic health and influencing it through the skin barrier, and we talked about senescent burden and the hallmarks of aging, et cetera. We covered a ton in this conversation and it was really stimulating, as always. I’m thrilled with the depth and breadth of science that they bring to the table.

Dr. Kara Fitzgerald:  As always, thank you so much for listening. If this conversation sparked ideas or shifts in how you’re thinking, let me know. We’re a community and I love to hear from you and hear what you have to say. Go back to the show notes, please, if you want to get the full transcript. It’s all free. We pull all the citations that we referenced in our conversation and they’re there for you in the show notes, as well as all my previous conversations with the Team OneSkin.

Dr. Kara Fitzgerald:  And be sure to hit like or leave us a review wherever you’re listening to this podcast. I’ll see you next time on New Frontiers in Functional Medicine.

Dr. Carolina Reis Oliveira is the co-founder and CEO of OneSkin, a longevity-focused skincare company developing products designed to address skin aging at the cellular level.

A longevity scientist with a PhD in stem cell biology, tissue engineering, and immunology, her work centers on targeting senescent cells, one of the key biological drivers of aging. Driven by an early fascination with biology and a commitment to extending healthspan, Dr. Reis Oliveira has focused her career on delaying the onset of age-related disease by targeting aging itself.

After completing her academic training, she moved from Brazil to Silicon Valley and co-founded OneSkin in 2016. As CEO, she leads the company’s research and development efforts, including work on molecules that target cellular aging and OneSkin’s proprietary OS-01 peptide.

Carolina Reis Oliveira, PhD

OneSkin Publications

OneSkin: The Science Behind The Claims

People Mentioned

Dr. Mariana Boroni, OneSkin co-founder and MolClock creator

Steve Horvath, PhD, ScD

Research on OS-01 Peptide

Clinical efficacy of OS-01 peptide formulation in reducing the signs of periorbital skin aging

OS-01 Peptide Topical Formulation Improves Skin Barrier Function and Reduces Systemic Inflammation Markers: A Pilot 12-Week Clinical Trial

Senotherapeutic peptide treatment reduces biological age and senescence burden in human skin models

In vitro and in vivo toxicity assessment of the senotherapeutic Peptide 14

Highly accurate skin-specific methylome analysis algorithm as a platform to screen and validate therapeutics for healthy aging

Double-blind, vehicle-controlled clinical investigation of peptide OS-01 for skin rejuvenation

Other Research Mentioned

Perceived Age, Senescent Cell Burden and Comorbidities

Past episodes with OneSkin

Podcast: Aging & Hair Loss Explained: OS-01’s Science-Backed Approach

Podcast: Targeting Cellular Senescence for Healthier, More Youthful Skin

Podcast:  Disrupting Anti-Aging Skincare by Targeting Senescent Cells

Blog: Biohacking Your UV Defense: How Antioxidants Optimize Your SPF

Blog: Why Skin Health is the Ultimate Test of Longevity

Blog: How the OS-01 Peptide Works to Reverse Skin’s Biological Age

Bio Age Self Assessment Quiz

Younger You book

Better Broths and Healing Tonics book