Peptides, Growth Factors, and Exosomes

Peptides, growth factors, and exosomes are becoming some of the biggest buzzwords in skincare, but what do they actually do? Dr. Zain and Courtney break down the differences between these powerful molecules, how they communicate with skin cells, where they come from, and what the current clinical data tells us.

The conversation covers collagen supporting peptides, growth factors involved in wound healing and tissue repair, and exosomes as a delivery system for different signaling molecules. They also discuss sourcing, the importance of clinical testing, PDRN, and why the formulation and stability of these ingredients matter.

Dr. Zain and Courtney also share some of their favorite products, including SkinMedica TNS, Neocutis, Revision, and Nectifirm. They explain how procedures such as microneedling, RF microneedling, and lasers can enhance the delivery of these ingredients into the skin, and why combining different products may help maximize results.

The episode wraps up with a discussion about the importance of looking critically at skincare claims and relying on meaningful clinical data rather than marketing alone.

00:00 Introduction to peptides
01:00 How peptides work with skin cells
02:00 Growth factors and cellular signaling
03:00 What are exosomes?
04:00 What peptides can do
05:00 Where peptides come from
07:00 Clinical data on peptides
08:00 Understanding growth factors
10:00 Clinical evidence for growth factors
11:00 Favorite growth factor products
12:00 Introduction to exosomes
14:00 Why exosomes are so delicate
15:00 Human derived vs plant derived exosomes
17:00 PDRN and emerging skincare ingredients
19:00 Exosomes vs growth factors
20:00 What the clinical evidence says
21:00 Enhancing skincare delivery
22:00 Combining peptides, growth factors, and exosomes
24:00 Why clinical data matters
25:00 Looking ahead in skincare

Creators and Guests

Host

Courtney Carroll, LE

Courtney Carroll, LE is a licensed aesthetician with extensive experience performing non-invasive cosmetic treatments and customized skincare.

Host

Dr. Zain Husain, MD

Dr. Zain Husain, MD FAAD FACMS is a dual board-certified dermatologist and Mohs micrographic surgeon with fellowship training in cosmetic dermatology.

What is Skinside Out?

Welcome to Skinside Out, where science meets beauty, the ultimate dermatology podcast! Dive deep into the fascinating world of skin health with expert insights, evidence-based discussions, and myth-busting truths. Each episode explores the medical, cosmetic, and surgical aspects of dermatology, while keeping you informed about trending skincare topics. Whether you’re a skincare enthusiast, medical professional, or just curious about how to achieve your best skin, Skinside Out is your go-to resource for staying informed and inspired.

71 Skinside Out - Topical Peptides
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Dr. Zain: [00:00:00] Welcome to Skin Side Out. I'm your host, Dr. Zane, with Courtney. So today we're talking about peptides, exosomes, growth factors in our skincare. So I know peptides are really popular these days. Everyone's talking about them. So what exactly is a peptide?

Courtney: So a peptide is basically a small chain of amino acids.

Um, they have been around for a very long time in the skincare realm. Um, I think there has been a lot of, um, interest in peptides due to, you know, the fact that they will help to build collagen. Um, but we'll kind of take a little bit of a closer look into different types of peptides, where they're sourced from, how they're delivered into the skin, and what makes a good peptide.

Dr. Zain: Yeah. And just to clarify, so amino [00:01:00] acids are like the building blocks, make peptides, which are essentially what proteins are made out of. Mm-hmm. So there are a lot of different peptides. Yes. So the ones that we're gonna be talking about are specifically those that interact with cells to, you know, produce changes, um, either in function or production of molecules such as other proteins or sugar molecules.

So there's a variety of different functions, um, these peptides play.

Courtney: Mm-hmm.

Dr. Zain: All right. So, um, we talked about what a peptide is, topical peptides. . So let's talk about the big picture.

So peptides are, you know, a common term, but let's kind of r- like classify them further. So there are differences. There's peptides, there are growth factors, and there are exosomes. Can you give us a little bit more information about what these are and how they're different?

Courtney: Yeah. So I think it's important when you think about the skin, um, y- [00:02:00] you kind of wanna think about it as like this communication network.

So your skin cells are always sending and receiving, um, almost like messages you can think about. Um, so some molecules are gonna act like instructions and some will act like signals. So growth factors are signaling proteins. Um, they help influence your cellular behavior, so things like proliferation, migration, um, wound healing, matrix production.

So, you know, the, the importance in the skincare world has been, um, you know, in regards to the wound healing and then the, the building collagen, and that's where they kind of have gained traction in this realm.

Dr. Zain: Yeah. And then what are exosomes?

Courtney: , Exosomes are these tiny little membrane-bound extracellular vesicles. Um, they're released by your cells, and they can carry a mixture of messages. So, you know, they influence things like your lipids, your proteins, um, other signaling molecules, RNA. So they're kind of little [00:03:00] almost like messenger cells you can think of them as.

Dr. Zain: Yeah. Um, I kind of think of them as like this little ball.

Courtney: Mm-hmm.

Dr. Zain: It has this lipid-bound, um, like surface.

Courtney: Mm-hmm.

Dr. Zain: And inside are the treasures. Yeah,

Courtney: yeah, yeah.

Dr. Zain: So you have these molecules. So they can contain peptides or, you know, small branched, you know, amino acids. Um, they can contain all these other regulatory molecules, so not necessarily just peptides.

So, you know, growth factors can be found within exosomes- Mm-hmm, mm-hmm ... and it's just a delivery system.

Courtney: I was gonna say, I think of them like UPS, like little UPS guys.

Dr. Zain: Yeah. Hopefully they're better than ones that bring packages- ... to our office. Well, they

Courtney: are out throwing the packages.

Dr. Zain: Um, so let's kind of move on to what peptides can actually do.

So the peptides that we see in skincare, um, can achieve a variety of different functions. So we're looking at signaling or carrying [00:04:00] molecule or signals, um, enzyme inhibition, meaning that we're trying to reduce the effects of certain, you know, proteins in the skin or in the body. Um, neurotransmitter modulating peptides, these are peptides that kind of help regulate how, for instance, like muscles contracts, like for like Botox- Mm-hmm

or things like that. And then there's collagen-supporting peptides, so these are more structural. So you can see there's a diversity. Um, there's a lot of different things that these molecules can do, and it's important to understand what these molecules are doing because you're really thinking about what the end effect and what you're trying to achieve with that skincare product, right?

So if you're trying to build collagen, you want more of that structural component. Um, if you're trying to reduce, you know, muscle movement, you want something that's gonna inhibit some of those signalings, um, molecules and signaling pathways.

Courtney: Yeah, and I think it's [00:05:00] important to kind of know where your peptides are coming from.

I think it's so easy to slap on like peptide onto any skincare product. But, you know, most of the cosmetically manufactured peptides are gonna be like synthetically manufactured, so, um, you know, or maybe like produced. So it's not like they're like getting these peptides from a human that they like processed- Mm-hmm

through and, you know, filtered through and are, are putting in there. Most of them are gonna be synthetically made.

Dr. Zain: Yeah, especially in like the large quantities- Mm-hmm ... that are needed to produce these products. However, there are like some, you know, peptides that are derived from cell lines.

Courtney: Mm-hmm.

Dr. Zain: And obviously, that is a very vigorous process- Mm-hmm

purification and making sure that they're pure.

Courtney: Mm-hmm.

Dr. Zain: So always kind of look at the product, see what it contains, and where they're sourced from.

Courtney: Yeah. Absolutely.

Dr. Zain: All right. So what do they actually do? So we talked about [00:06:00] signaling and how these peptides can interact with different pathways. So similar to like medications, right?

Mm-hmm. They can affect different pathways and can affect cellular metabolism and how things function. Others can bind metals. Mm-hmm. Um, others may influence other enzymes. So like I said, a lot of variety. In dermatology, we also see things, um, like how it can influence pigment-

Courtney: Mm-hmm ...

Dr. Zain: right? Mm-hmm. Or inflammation.

I mean, a lot of our medications, you know, have certain, you know, peptides that can help with reducing inflammation or, you know, causing some other effect that we're looking for.

Courtney: Mm-hmm. Yeah. I think peptides, one thing about them is that definitely there is a lot of, I would say, data there. Um, you know, it's...

When we're looking at kind of their... our newer, which we'll get into, like growth factors and exosomes, but peptides have been kind of a, a tried and true I would say. So, um, I know there's like one, one study they did where they, uh, [00:07:00] compared it to retinol and as well as just like placebo vehicle. Um, and it was really interesting.

They, um, were finding reduction in like crow's feet, forehead wrinkles, um, you know, compared to the people who were using retinol. So I think it's interesting looking at the studies. I mean, no one's saying like, "Throw your retinol away" but- Mm-hmm ... these are just things that you can use in adjunct to kind of, um, amplify, I guess, your, your results, so.

Dr. Zain: Yeah. And I really only advocate for products, um, that have peptides that have gone through rigorous- Yeah ... uh, clinical testing.

Courtney: Mm-hmm.

Dr. Zain: Because anyone can say, you know- Yeah ... it's a peptide, but is it really efficacious? And there needs to be a lot of data and studies behind it. So that's where, you know, some of the more reputable skincare companies, I mean, they go the distance- Mm-hmm

to see, um, if these molecules truly work, and that's why they come up with like a, a higher price tag. Mm-hmm. I mean, research and development and kind of proving that these, um, molecules work, I mean, it's, it's important. Do your research.

Courtney: Cool.

Dr. Zain: Yeah.

Courtney: Let's talk [00:08:00] about some growth factors.

Dr. Zain: All right. So growth factors are very exciting.

They're a specialized signaling molecule that will help with a variety of different cellular processes. So whether it's cell proliferation, uh, migration, wound healing, um, extracellular matrix remodeling, collagen production, tissue repair. I mean, there's so many different functions these growth factors play a role in.

And, you know, we have a lot of these growth factors in our bodies.

Courtney: I was gonna say, we produce them. Yeah.

Dr. Zain: Yeah. So these aren't like foreign, you know, molecules. They're nothing that we don't already contain in our bodies, and these are the same type of, you know, molecules that are helping us with, you know- wound repair, with regeneration, with reducing inflammation.

So they are vital for optimal functioning.

Courtney: Mm-hmm. Like you think of, uh, you know, PDGF that's been very popular in the cosmetic realm, so platelet-derived growth factor. But then you have other growth [00:09:00] factors like fibroblast growth factors, epidermal growth factors, um, you know, TGF-related signaling molecules, so, you know, your inflammatory processes.

Um, so yeah, there's a lot of different types of growth factors. And then, you know, same, same as the peptides, depending on where your company is sourcing these from, again, could that be through, um, you know, a human means like Neocutis, who sources theirs, uh, theirs are human-derived, um, growth factors? Or could it be, again, like bioengineered?

So you really wanna check that, that sourcing because like you said before, it is incredibly difficult to purify those, uh, growth factors, to stabilize them, to keep them stable, and then to transmit them to the skin. I mean, that... It's so crazy thinking about the technology on some of these companies because you, it's like each little step is a miracle, you know?

Yeah. I mean, just to get it, yeah, just to even extract it, just to stabilize it, just to make sure it's shelf stable, to get it into your skin, I mean, it's, yeah, each step is a whole, I think, miracle in itself.

Dr. Zain: Yeah, for sure. [00:10:00] It's really interesting science. Um, so what about the clinical data behind growth factors?

What are we seeing in skincare?

Courtney: Yeah, I think we definitely are seeing, um, studies that are coming out in regards to, you know, um, skin texture, fine lines, wrinkles, um-

Dr. Zain: Hydration ...

Courtney: hydration. That's been a huge one. Um, I think most people are starting to see results at kind of like the three-month mark. Um, again, I think it kind of depends on the product, the type of growth factor that the study was done on, and then the different formula- formulations.

But I think, also, like one thing to take into account with some of these studies is, you know, when you're in the realm of cosmetics, sometimes some of those improvements are subjective. Mm-hmm. So how do you, how do you tell, how do you tell a patient? It's like when you have a patient come in- Yeah ... and you see wrinkles, and you're like, "Oh, I could treat those wrinkles."

They're like, "I don't have any wrinkles." Like, we're at a, an, an impasse. Yeah. So I think it's a little bit of subjective data, but, you [00:11:00] know, if people are feeling like they're seeing improvement, then I think it's worth looking into further.

Dr. Zain: So let's talk about some real-life, um, applications that we've used.

Like some of our favorites, I know you mentioned Neocutis. Mm-hmm. Love them. Mm-hmm. Um, some other products that I've really been impressed with, like, I think the OG is TNS.

Courtney: Yeah.

Dr. Zain: Um, so this is a product by SkinMedica. I think the real first product- Mm-hmm ... um, that was successful with incorporating, um, these growth factors.

Mm-hmm. And patients got great results. Um, and you know, I still remember when I first used it, um, I was pretty impressed with it.

Courtney: Mm-hmm.

Dr. Zain: Um, although it did tend to make me break out a little bit.

Courtney: Yeah. Yeah. Yeah, and I think you, I remember you saying something about like the smell. I know they like re- they

Dr. Zain: redid it.

Yeah, the original did smell. You know I'm very sensitive to smells.

Courtney: Yeah, yeah. Well, I guess they re- they probably heard those concerns, and I, I haven't noticed the new one having a

Dr. Zain: smell. Yeah. So I'm a big fan of that, um, product especially. The Neocutis line I [00:12:00] really do like. Um, I really like also Revision's products.

I do

Courtney: too.

Dr. Zain: They, they do contain growth factors. I love their Nectifirm.

Courtney: Yeah.

Dr. Zain: Um, has peptides, um, has growth factors that help with, you know, creepiness- Mm-hmm ... fine lines, wrinkles, you know, helps reverse some of that sun damage.

Courtney: I like Revision a lot. I think their peptides are really solid, and I feel like they were kind of early in the game when it comes to the whole, um, like peptide, you know, trajectory.

So I have a lot of respect for them.

Dr. Zain: Cool. All right, so let's enter the exosomes. I mean, exosomes are super trendy right now. Oh,

Courtney: it's a, such a buzzword. Like, what is... You know, we defined what- It just sounds interesting, right? Yeah. Like, exosome. Sounds just sci-fi. Yeah, I think exosomes are really entering the game, and I think it's really fascinating to see.

You know, w- what's funny about... And I was actually just talking to a patient about this earlier, but what's funny about a lot of these, um cosmetic treatments is I think it's always so cool and interesting seeing, like, where they come from and how they [00:13:00] even figured this stuff out. So you know, like, uh, I know with Plated, like, you know, they got their exosomes.

They were studying them for actually ulcers, like diabetic foot ulcers, which is, like, not sexy or glamorous, but it was really helping. That's painful. Yeah. Nasty. But, um, they were finding the residents were actually using the exosomes on their hands. You know, they were getting eczema from, like, the gloves- Mm

constant washing of the hands, and those exosomes were healing their eczema.

Dr. Zain: That's so

Courtney: cool. And it's actually the wife of the, the doctor who was running the study that was like, "Wait, wait, wait. Like, we should figure out how to do something, like, cosmetically. 'Cause if this is helping with that, like- Yeah

what else can it do?" And yeah, I think it's just really cool that, yeah, it started as kind of this medical, um, interest, and we've seen it transform into this cosmetic boom. So.

Dr. Zain: And you know what's really cool about them is that the structure is what really helps the, you know, signaling molecules get into the cell where it needs to be, right?

Courtney: Mm-hmm.

Dr. Zain: That, like, lipid [00:14:00] membrane- Mm-hmm ... allows it to penetrate. And by increasing the successful penetration, um, of the signaling molecules, we're able to get a more robust response.

Courtney: Mm-hmm.

Dr. Zain: So exosomes, I mean, I think whoever, you know, kind of discovered, you know, that we can use these types of growth factors and have them, like, packaged in this delivery system-

Courtney: Mm-hmm

Dr. Zain: is genius.

Courtney: Yeah. I think, you know, it's interesting about the, the lipid, um, layer because while that is a blessing, it's almost like the exosomes' downfall too because that layer is so fragile that as soon as it's broken, you're- Mm-hmm ... losing that exosome, which I think is so important when you're talking about products that are labeling things, "Oh, we have exosomes."

Because they are so delicate, you really have to ensure that that process that you're using to, to- Yeah ... purify it, to, you know, stabilize it, that you're not breaking that lipid layer, or else you're not getting any benefit from it. [00:15:00]

Dr. Zain: Yeah. And on the cellular level, I mean, our cells produce these microvesicles, and they fuse with the membrane.

And you know, this concept already happens- Mm-hmm ... in our bodies anyway. Mm-hmm. So this is just one of the ways that we can manipulate, um, the same delivery system to really get the results that we're looking for.

Courtney: Mm-hmm.

Dr. Zain: So I think it is really cool.

Courtney: Yeah. I think, you know, another question to kinda ask is again, like, yeah, source, source of, um, your exosomes.

So you know, they, there are plant-derived, um, exosomes. I- personally think human-derived do a lot better. I mean, you think about human cells talking to human cells, right? Um, human cells don't really wanna talk to plant cells. There's not that same, um, yeah, interaction you could say. But, um-

Dr. Zain: What if the, what if the patient's vegetarian?

Courtney: I'm vegetarian.[00:16:00]

Maybe the plant ones work better on you. Yeah. Um, and I think some people, it's funny you say that though because some people do get a little, like-

Dr. Zain: Mm-hmm ...

Courtney: weirded out. Like, so what do you mean they're, they're taking... Like for example, you know, I'll go back to Platelet again, but you know, they're taking, um, healthy blood from blood donors.

Um, and they are purifying that blood. They, um, are actually using people between the ages of 20 and 40, so these are young, healthy people. Um, and yeah, they're, they're utilizing those exosomes within their blood essentially. And so I think, yeah, it's a little, um, weird when you think about it, but-

Dr. Zain: But a lot of biotech, um, you know, products-

Courtney: Yeah

Dr. Zain: and you know, things that we use in medicine are derived from- Yeah ... resources outside of our bodies, right?

Courtney: Mm-hmm.

Dr. Zain: So I don't think it's that weird.

Courtney: Yeah. I don't get weirded out. Whatever. Honestly- Whatever works ... people are putting salmon sperm on the... Like, I think we're so past the point of caring. Yeah.

Like where it comes from, as long as it works. Yeah.

Dr. Zain: I mean, speaking about the salmon sperm, um, products, which is, you know, [00:17:00] PDRN- Mm-hmm ... polydeoxyribonucleotides, um, essentially they function like these- Mm-hmm ... growth factors. Mm-hmm. Um, it influences the skin, the health, hydration- Mm-hmm ... um, helps to stimulate, you know, some protein synthesis.

Mm. And I mean, it is basically a form of genetic, like, you know, material that- Mm-hmm ... like the break, like the bro, like the little building blocks. I mean, it's, that's what's, that's what's doing it. And- Yeah ... that's how our cells kind of create some of these peptides.

Courtney: I remember being like in high school and like when like stem, like just the verbiage of this abstract stem cell therapy, you know, such a big deal- Yeah

'cause people are like, "They're taking cells from babies," and like it was like- Yeah ... this is so sci-fi and crazy. And now it's- Yeah ... like an umbrella term for all of these like legitimate processes that are going on. But I remember at the time being like, "This is the future." Yeah.

Dr. Zain: Um, and these exosomes can carry a [00:18:00] variety of different signaling molecules and types of molecules.

So you know, whether it being RNA, PDRN, um, or you know, other signaling molecules, they just have so much- flexibility in terms of what, um, we can influence the cells with.

Courtney: Mm-hmm. Yeah. And I think they can also tackle multiple concerns. Mm-hmm. I mean, you see uptake of, like, your glutathione, which again is a naturally, um, occurring thing in your body.

But just helping to, yeah, uptick that, your, um, like antioxidants, um, you know, pe- your own peptides that you're naturally making. So yeah, I think, um, y- you're maximizing your cells' function really. So- Yeah ... yeah.

Dr. Zain: Pretty cool. So a lot of people get confused between exosomes and growth factors. Um, they essentially say that they're the same thing.

So they're not necessarily the same thing. Um, so with growth factors, you know, those are [00:19:00] signaling molecules, right? They can basically cause some function to occur. However, exosomes are like that package delivery system, and they can contain growth factors in them. But just to kinda make that distinction, um, I think a lot of people use those two terms synonymously.

Courtney: Mm-hmm.

Dr. Zain: Yeah.

Courtney: Yeah.

Dr. Zain: All right, and what does the clinical evidence say about exosomes? What do we know so far?

Courtney: You know, it's still early. Mm-hmm. And, I know we've talked about this, I think in our last episode, about sometimes the data hasn't caught up to, you know, uh, the happening. But, um, it's still early on.

They are showing improvements in things like collagen production, elastin, um, elasticity, um, hydration, pigmentation. Um, so I think just an overall, um- You know, how, I mean, again, when you just think about what they're doing in, in that signaling, um, again, things like the glutathione, you're like, "Okay, we know that that helps pigment," so yes, it makes sense that there's gonna be reduction in [00:20:00] pigment.

Or, yes, we know that it's maximizing peptides, so we know that there's gonna be a reduction in, um, fine lines, wrinkles. So yeah, there's early, early data, but I think there's probably a lot more to be done.

Dr. Zain: Got it. So let's move on to delivery of these topical skincare products containing either peptides, exosomes, um, growth factors.

So obviously, skincare has been formulated so that it can absorb into the skin, but we can also enhance penetration and help those molecules get in even easier. So how do we do that in the office?

Courtney: So I think opening microchannels through means such as, like traditional microneedling, even RF microneedling, um, different types of lasers. You know, we use LaserMD in our office. Um, but anything that's going to create that microchannel, um, is really going to help deliver, whether it's an exosome, a growth factor, a peptide, um, really gonna enhance that delivery.

You know, obviously it's... has a path right in, [00:21:00] so.

Dr. Zain: And also, just the physical nature of the procedure is gonna be a wound response- Mm-hmm ... leading to inflammation, bringing growth factors and, you know, other molecules that are gonna help with the healing process. Mm-hmm. So I think it just kinda synergistically- Mm-hmm

um, helps in that respect.

Courtney: Oh, 100%. Yeah. I mean, that's what a lot of these pr- you know, these were for in the human body is to help aid in, yeah, wound healing. And so it just makes sense that, yeah, you do something that is, you know- creating inflammation in the skin, and we are adding something to help decrease that.

Yeah. So.

Dr. Zain: Cool. Um, so out of these different molecules that we discussed, peptides, exosomes, uh, growth factors, what is the best based on the data?

Courtney: You know, I use them all, so Yeah.

Dr. Zain: I do, too. Yeah.

Courtney: I think, yeah, they each work differently. And I think when we're [00:22:00] looking to get the best outcome for our skincare or for a treatment, um, yeah, I am a, a maximalist in that regard.

You might as well, um, use them all.

Dr. Zain: Yeah. I mean, I do think there's synergy with products, and not even with, you know, these growth factors, peptides, exosomes. I mean, they're gonna enhance the effects of other molecules, right? So the retinoids- Mm-hmm ... it's gonna help those retinoids function and cause more of those changes that we're looking for.

The vitamin C serums, um, a variety of different other skincare, um, products that we typically use, it just enhances that function.

Courtney: Yeah.

Dr. Zain: And then I know that we've talked about ReQue in a few of our podcast episodes. This actually helps to enhance the function of all of these skincare products. Mm-hmm. And that's why I think it's such an exciting, uh, skincare product and how that enhances everything else that you apply to your skin.

Mm-hmm. So it kind of resets those [00:23:00] fibroblasts. It helps to, um, allow them to rest so they can ultimately function at highest capacity and they don't get burned out.

Courtney: Mm-hmm.

Dr. Zain: So I do think that, you know, combining that with any of these products that we're talking about can help enhance results.

Courtney: Yeah. I was gonna say, it's really cool, you know, those, like, before and afters on those fibroblasts.

Um, you know, and one more thing I was gonna touch on just about different companies, you know, utilizing these different words as, uh, advertising for their products, but, you know, I know there's always been a hot debate between, um, like, medical grade skincare versus, like, over-the-counter. And, you know, we've talked about that a little bit and how, yeah, maybe there's some things we can kind of, you know, work with.

But a lot of these, um, companies are doing, like, you know, biopsies. They're show- Like, the, the data that they're doing to show the improvement is, is substantial. And yeah, even the ReQue, when we were able to see kind of like that- Mm-hmm ... that fibroblast. Yeah. I mean, you see that clear picture of that weak little, like, [00:24:00] loser-looking fibroblast.

Is it? And then it's like it's all structured. So yeah, I think it's important doing things like that, like punch biopsies and, um, just showing that clinical data of, like, hey, this is working.

Dr. Zain: Yeah. True data is really powerful. I mean, the subjective nature of it, eh. Yeah. Like, sometimes it's just- You know, in the eye of the beholder, like, you know, the researcher can, "Oh, yeah, it looks brighter- Yeah

or it looks more hydrated."

Courtney: Placebo works for a reason. Right. You know? I mean, and I always say if it- I don't care if it's placebo, as long as it's working. Yeah. But yeah, the data's nice to have, too.

Dr. Zain: And honestly, like, sometimes the vehicle- Mm-hmm ... that the, you know, peptide is in is actually hydrating the skin, making it look better.

Mm-hmm. So, you know.

Courtney: Yeah.

Dr. Zain: You always have to look at it with a critical eye.

Courtney: Yeah.

Dr. Zain: All right. So I think we are concluding this episode on topical peptides, growth factors, and exosomes. It's a fascinating new era in skincare. I am excited to see what comes next. Um, and, you know, I [00:25:00] do think that things are gonna evolve further as we, you know, learn more behind the cellular pathways and how we can influence them.

So- Mm-hmm ... exciting times ahead.

Courtney: Yeah. Yeah.

Dr. Zain: All right. So hopefully you enjoyed this episode. Please follow, like, and subscribe. But until next time, Skin Side out.