What if the hottest ingredient in skincare isn't even an ingredient?
Exosomes are everywhere. In your Instagram feed. On the shelves of your favorite beauty store. In clinic menus from Brussels to Beverly Hills. The claims are breathtaking: "cellular rejuvenation," "DNA repair," "300% collagen boost." Prices range from €23 serums to €800 clinic sessions. The marketing reads like a PhD thesis crossed with a perfume ad.
And here's what makes this one different from LED masks or collagen supplements: the biology behind exosomes is genuinely fascinating. These are real structures, doing real things in your body, right now. The science of extracellular vesicles is one of the most exciting frontiers in cell biology.
But between that frontier and the jar on your bathroom shelf lies a gap so wide you could park a clinical trial in it — if anyone were running one.
How media coverage turns biology into belief
Popular media coverage of exosomes often follows a familiar pattern: expert quotes, references to peer-reviewed studies, and confident scientific language. The result feels authoritative and reassuring — real doctors, real journals, real biology.
However, most studies cited in lifestyle articles examine exosomes in laboratory models, wound healing, or regenerative medicine, frequently involving direct delivery into tissue. These contexts are fundamentally different from topical cosmetic products applied to intact human skin. When such studies are cited alongside at-home skincare products, an equivalence is implied that has not been demonstrated in controlled clinical trials.
Expert commentary in these articles typically explains what exosomes are and what they can do biologically — not whether specific consumer products actually deliver those effects. When delivery method, dose, and level of evidence are removed from the discussion, scientific credibility travels further than the data itself.
The biology of extracellular vesicles is real and promising. The gap lies in how easily that promise is extended — from experimental and regenerative medicine to consumer skincare — without the level of evidence such claims would normally require.
What exosomes actually are
Every cell in your body communicates. Not through words, obviously — through tiny packages. Your cells constantly release nanoscale vesicles (30–150 nm, roughly 1,000 times smaller than the width of a hair) that carry cargo: proteins, lipids, RNA, signaling molecules. These packages travel to neighboring cells — or distant ones — and deliver instructions. "Make more collagen." "Reduce inflammation." "Start repairing."
This is real biology. It's called intercellular communication via extracellular vesicles (EVs), and it's been studied intensively for over two decades.
The word "exosome" technically refers to a specific subtype of these vesicles — those that originate from the endosomal pathway inside cells. This distinction matters, and we'll come back to it, because it's the source of an enormous scientific naming problem that the marketing world has cheerfully ignored.
A common source of confusion is that “exosome” has been used in multiple biological contexts.For example, plant biologists have long observed that plants release nanoscale extracellular vesicles that were historically referred to as “exosomes” in the context of plant immunity and intercellular signaling. These vesicles share size characteristics with human exosomes (30–150 nm) and carry cargo such as proteins and RNAs — but their biochemical content, membrane markers, and physiological roles are distinct from human or animal extracellular vesicles.The International Society for Extracellular Vesicles (ISEV), whose standards we discuss below, now recommends using operational terms like “small EVs” unless the endosomal origin has been proven, precisely because the historical use of “exosome” covers biologically different vesicle populations across species.In other words: yes, plants deploy EVs that were once called “exosomes,” but calling those the same thing as human regenerative exosomes is a categorical error. That difference matters because clinical evidence for human EV therapy cannot be transferred from plant EV observations, nor does plant EV biology justify clinical marketing claims in skincare.
The therapeutic logic is seductive: if cells use exosomes to signal repair, what if we could harvest those signals and apply them to aging skin? Boost collagen, reduce pigmentation, accelerate healing — all by delivering the right biological messages?
It's a beautiful hypothesis. The question is whether anyone has actually proven it works — in humans, on skin, in a way you can buy.
What "clinically proven" actually means (a regulation detour worth taking)
Before we look at the evidence, we need to talk about something that affects every product claim you've ever read on a label, not just exosomes. Because the phrase "clinically proven" does not mean what most people think it means.
In the EU: the rules sound strict. The enforcement... less so.
Cosmetics sold in Europe are governed by Regulation (EC) No 1223/2009 — a comprehensive framework that requires every product to have a safety assessment, a Product Information File (PIF), and notification through the European CPNP portal before going to market. Claims are further regulated under Commission Regulation (EU) No 655/2013, which establishes six criteria: claims must be truthful, supported by evidence, honest, fair, informed by the needs of the target consumer, and made with respect for competitor products.
Sounds reassuring, right? Here's the catch.
No claim is pre-approved. There is no European agency reviewing your serum's marketing copy before it hits the shelf. The system is post-market: you must have the evidence, but nobody checks it before you sell. They only look if someone complains, or if a regulator decides to investigate. The Product Information File — which should contain proof supporting every claim — sits with the Responsible Person. It's not public. You'll never see it.
So when a serum says "clinically proven to boost radiance in 14 days," what does that mean in practice? It means the manufacturer has something in a file somewhere that they believe supports that statement. It might be a peer-reviewed, placebo-controlled clinical trial. It might be a self-assessment questionnaire where 26 women said their skin "felt more radiant." Both can technically live in a PIF. Both can technically support the word "clinically." The regulation says evidence must be proportional to the claim — bigger claims need stronger proof — but the line between "adequate" and "creative interpretation" is drawn in pencil, not ink.
The six criteria in Regulation 655/2013 also state that claims must not "attribute to the product characteristics that it does not possess." Lovely sentence. Now try enforcing it across 31 countries and a few hundred thousand products. The EU Technical Document on Cosmetic Claims, last updated in 2023, provides examples and guidance — but it's not binding, and enforcement varies wildly between member states.
One more detail that matters for exosomes specifically: EU cosmetics law prohibits products from making therapeutic or medicinal claims. A cream cannot say it "treats" wrinkles, "heals" scars, or "cures" pigmentation. Those words push a product into pharmaceutical territory — specifically, into Advanced Therapy Medicinal Product (ATMP) territory under Regulation 1394/2007, which requires full clinical trials and authorization through the European Medicines Agency's Committee for Advanced Therapies. Nobody in the exosome serum market wants to go there.
So the marketing adapts. Instead of "repairs skin," you get "supports skin's natural repair." Instead of "boosts collagen production," you get "stimulates collagen synthesis" — buried under an asterisk that leads to an in vitro study on cells in a dish, not human faces.
In the US: different system, same dance
The American approach to cosmetics regulation is historically simpler — and until recently, remarkably permissive. Before 2022, the FDA's core authority over cosmetics hadn't been meaningfully updated since 1938. Yes, 1938. The era of Roosevelt, radio, and regulated railroads.
In December 2022, Congress passed the Modernization of Cosmetics Regulation Act (MoCRA), the first major overhaul in 84 years. MoCRA introduced facility registration, product listing, adverse event reporting, mandatory safety substantiation, and — eventually — binding Good Manufacturing Practices. It was a significant step.
But here's what MoCRA did not do: require pre-market approval for cosmetics. Just like the EU system, cosmetics in the US can go to market without the FDA reviewing them first. The safety evidence must exist, but it doesn't need to be submitted. The FDA monitors the market and can take action — but only after the fact.
The US system adds another layer that's relevant to exosomes. Under the Federal Food, Drug, and Cosmetic Act, a product that claims to affect the structure or function of the body is not a cosmetic — it's a drug. A drug needs FDA approval before it can be sold. This creates an absurd linguistic ballet that anyone who reads skincare labels will recognize:
A moisturizer can say it "improves the appearance of fine lines" (cosmetic claim — fine).It cannot say it "reduces wrinkles" (structure/function claim — that's a drug).
"Improves the look of firmness" — cosmetic. "Stimulates collagen production" — drug. The entire marketing vocabulary of the skincare industry is reverse-engineered from this distinction. Every word is chosen not for accuracy, but for regulatory survivability.
And here's where it gets interesting for exosomes: the very reason they're exciting to biologists — they carry signals that change how cells behave — is precisely what makes them legally precarious. If a product actually delivered functional exosomes that modified collagen synthesis, it wouldn't be a cosmetic. It would be an unapproved drug.
The industry's solution? Make the marketing sound biological without technically crossing the line. Use the word "exosome" for its scientific prestige. Cite in vitro studies that show cellular effects. Let the consumer connect the dots. And keep the asterisks small.
The bottom line on regulation
The regulatory systems in both the EU and the US are designed around a fundamental assumption: the manufacturer is responsible for honesty. The system trusts that evidence exists. It checks after the fact, if at all.
This works reasonably well for moisturizers and lip gloss. It works less well when an entire product category is built on frontier science, in vitro extrapolation, and a word that the scientists who study it recommend not using.
What the clinical evidence actually shows
Now, to the human trials. This is where things get quiet.
In 2025, Domaszewska-Szostek and colleagues published a systematic review in the International Journal of Molecular Sciences evaluating the clinical evidence for extracellular vesicles in aesthetic dermatology. They found 12 clinical studies total — across all aesthetic indications combined: skin aging, acne scars, alopecia, wound healing. Twelve.
Pinto and Sánchez-Vizcaíno Mengual, in Aesthetic Plastic Surgery (2024), started with 633 articles and filtered down to nine clinical studies. They rated the overall level of evidence as Level III — observational and case series quality.
For context, the LED mask field — which we found to have significant evidence gaps in Episode 3 — had a landmark sham-controlled RCT with 76 patients (Lee et al. 2007), plus several other properly controlled studies. Exosomes have nothing equivalent.
Let's look at what exists, ranked by size:
The Wyles/Mayo Clinic/Rion Aesthetics program dominates the field. All studies use the same product — a human platelet extract (HPE) marketed as "plated" serum by Rion Aesthetics. All share overlapping authorship and extensive conflict-of-interest disclosures: authors are consultants for or employees of Rion; Mayo Clinic holds financial interest; studies are funded by the manufacturer. This doesn't automatically invalidate the work, but it defines the landscape.
The largest facial study (Proffer/Wyles 2022, Aesthetic Surgery Journal): 56 participants used the HPE serum for six weeks. Results: reduced wrinkles, redness, and melanin; 98.2% willing to continue. The problem? No control group. No blinding. No placebo. Participants knew what they were using and self-reported satisfaction. At 12 weeks, the same cohort showed collagen fibril thickness increases on biopsy (Wyles 2024, Journal of Drugs in Dermatology). Mechanistically interesting — but still no placebo arm, so we cannot separate product effect from time, skincare routine changes, or expectation.
The largest study overall (Wyles 2024, Plastic and Reconstructive Surgery): 60 participants compared HPE applied to one hand versus vitamin C serum (C E Ferulic) on the other for up to 26 weeks. The finding? HPE performed approximately as well as vitamin C — not better. Brown spot reduction was roughly 23% versus 26%. This was a non-inferiority design: the conclusion was equivalence, not superiority. And there was no placebo hand.
The best-designed study in the entire field (Weir/Wyles 2025, Plastic and Reconstructive Surgery Global Open): 39 participants, double-blind, placebo-controlled, testing HPE for hair growth over nine months. Significant improvements in volume and density. This is the only properly controlled study from the Wyles program — but it's for hair, not facial skin, with 39 participants and single-center enrollment. Rion-funded.
Other studies follow a pattern. Park et al. (2023, n=28) tested exosomes plus microneedling against microneedling alone — a combination design where you cannot attribute improvement to the exosomes. Kwon et al. (2020, n=25) did the same with exosomes plus CO₂ laser versus laser alone. Same problem. The device does so much to the skin that any additive exosome effect is nearly impossible to isolate.
Cho et al. (2020, n=21) ran a split-face, placebo-controlled study for pigmentation. Melanin reduction was significant at week four — but the effect had disappeared by week eight. The temporary result that nobody mentions.
There is no large (n≥100), independent, sham-controlled randomized trial for any aesthetic exosome indication. The largest facial study had no control group. The only properly controlled study (hair, n=39) is small and manufacturer-funded. Most positive findings come from combination designs that prevent attribution.
For a product category generating hundreds of millions in revenue, this evidence base is startlingly thin.
The penetration problem: your skin says no
Here's the part that should matter most to anyone considering an exosome serum.
Your skin has a barrier — the stratum corneum — and it's very good at its job. It keeps things out. Including, it turns out, exosomes.
Li et al. (2020, International Journal of Pharmaceutics) tested exosomes derived from human umbilical cord mesenchymal stem cells on porcine skin (a close model for human skin). Their finding: exosomes "could not readily penetrate through porcine skin by themselves." They required sponge spicules — tiny needle-like structures from marine sponges — to enhance absorption by about 5.87 times. But 5.87 times a very small baseline is still very small.
Laurent et al. (2024, Cosmetics) went further. After 24 hours of topical application, less than 1% of exosomal fluorescence was detected beyond the stratum corneum. The exosomes essentially sat on the surface. The authors stated that topically applied exosomes mainly act within the stratum corneum — the outermost, dead-cell layer of skin — not in the living dermis where collagen synthesis actually happens.
This is devastating for the serum market. If you're paying €23 — or €200 — for a topical exosome product, the vast majority of what you're applying is not reaching the cells it would need to reach to do anything biologically meaningful.
Microneedling or laser pre-treatment can breach the stratum corneum and potentially improve delivery. But that's a clinic procedure — not a home serum. And the combination designs in clinical trials make it impossible to know whether the exosomes or the skin-penetrating device did the work.
The name problem: even scientists can't agree what's in the bottle
In 2024, the International Society for Extracellular Vesicles (ISEV) published MISEV2023 — the Minimal Information for Studies of Extracellular Vesicles — in the Journal of Extracellular Vesicles. Over 1,000 researchers contributed.
Their recommendation: use operational terms like "small EVs" or "large EVs" unless endosomal origin has been specifically demonstrated. The word "exosome" implies a specific biogenesis pathway. In practice, most commercial products haven't proven that what's in the bottle actually went through that pathway. They might be exosomes. They might be other types of extracellular vesicles. They might be cellular debris. Without standardized characterization, nobody — including the manufacturer — can say with certainty.
There is no agreed-upon standard for exosome isolation, dosing, purity, or quality control across commercial products. Two products both labeled "exosome serum" may contain fundamentally different biological material.
And then there's source confusion. The exosomes in clinical trials come from human mesenchymal stem cells (bone marrow, adipose tissue, umbilical cord), human platelets, or adipose-derived stem cells. The exosomes in your drugstore serum typically come from plants — Centella asiatica, for example — or even salmon. These are biologically different organisms. The extracellular vesicles they produce carry different cargo, target different pathways, and have essentially no shared clinical evidence base. Marketing them under the same "exosome" umbrella is like calling a bicycle and a Boeing 747 "vehicles" and assuming they'll get you to Tokyo at the same speed.
The regulatory minefield
EU: human-derived exosomes don't belong in cosmetics
Under the framework of EC 1223/2009, cosmetics may only contact the external parts of the human body with the purpose of cleaning, perfuming, changing appearance, protecting, or keeping skin in good condition. Human-derived biological materials — including exosomes harvested from human cell cultures — sit in uncomfortable regulatory territory.
Human-derived exosome products used in clinic settings are treated as non-compliant in cosmetics under the existing regulatory interpretation. If a clinic injects human-derived exosomes with therapeutic claims (rejuvenation, healing, regeneration), the product falls under ATMP classification (Regulation 1394/2007) — requiring full clinical trials and EMA authorization through the Committee for Advanced Therapies. No such authorization exists for aesthetic exosome use.
In March 2025, an investigation by The Guardian and Business of Fashion found clinics in the UK illegally offering human-derived exosome treatments for aesthetic purposes — without authorization, without standardized products, and without informed consent regarding the regulatory status of what was being injected.
Plant-derived "exosomes" (more accurately: plant vesicle-like nanoparticles) in topical cosmetics occupy a grey zone. They're not human-derived, so the ATMP concern doesn't apply. But the claims made for them — collagen stimulation, cellular repair, rejuvenation — still need to comply with the truthfulness and evidence requirements of Regulation 655/2013. Whether a Centella-derived nanoparticle in a €23 serum can substantiate claims of "300% collagen boost" is a question that will presumably be answered whenever someone opens that Product Information File.
US: if it works, it's probably a drug
The FDA has been unambiguous about exosome products used as injectables. In December 2019, following serious adverse events in Nebraska — infections from unregulated exosome injections — the FDA issued a Public Safety Notification warning consumers against exosome products marketed for therapeutic use.
Since then, enforcement has escalated. Warning letters were issued to Kimera Labs (September 2023), Evolutionary Biologics (December 2024), and Chara Biologics (January 2025). The FDA's position: exosome products intended to treat, cure, or prevent disease, or to affect body structure or function, are biological products regulated under Section 351 of the Public Health Service Act. They require an approved Biologics License Application (BLA) or an Investigational New Drug (IND) exemption. There are zero approved exosome products for any indication.
For topical cosmetics, the same logic from the claims section applies: if the exosome serum only claims to "improve appearance," it can live in cosmetic territory. If it claims to "stimulate collagen," "repair DNA," or "rejuvenate at the cellular level" — those are structure/function claims, and the product is an unapproved drug.
Safety: what we don't know is the problem
There are no long-term safety studies for aesthetic exosome use. In a 2025 review published in Dermatologic Surgery, at least 10 serious adverse events had been reported in dermatological applications of exosomes.
The growth factor concern is not trivial. Exosomes carry bioactive cargo that can influence cell proliferation. In wound healing and oncology, this is a feature — you want cells to grow. In aesthetic dermatology, where the goal is cosmetic improvement in otherwise healthy tissue, the long-term implications of repeated growth factor delivery are simply unknown. A Cambridge scientist quoted in National Geographic (October 2025) raised the tumor-promotion concern directly.
This doesn't mean exosomes are dangerous. It means we don't have the data to say they're safe for repeated aesthetic use — and the absence of evidence is not evidence of absence.
What this means for you
The biology of extracellular vesicles is real, fascinating, and medically promising. Exosome research in wound healing, drug delivery, and regenerative medicine is a serious scientific field with genuine potential.
The aesthetic market has taken that promise and built a product category years ahead of the proof.
Here's what we know, honestly:
There are 12 clinical studies total across all aesthetic indications. The largest facial study had no control group. The only properly controlled facial comparison found exosomes performed about as well as vitamin C — not better. Less than 1% of topically applied exosomes penetrate past the outermost skin layer. The scientists who study extracellular vesicles recommend against using the word "exosome" without demonstrated biogenesis. There are zero approved exosome products in any jurisdiction. And "clinically proven," as it turns out, can mean almost anything the manufacturer needs it to mean.
If you're considering a topical exosome serum: you're likely buying a well-formulated moisturizer with standard active ingredients (hyaluronic acid, peptides, centella extract, niacinamide) that happens to have a very expensive word on the label. The exosome component, whether plant-derived or otherwise, has no standalone clinical evidence for skin rejuvenation and likely cannot penetrate your skin barrier in meaningful quantities.
If you're considering a clinic-based exosome treatment: ask your provider three questions. What specific product is being used? Is it authorized for aesthetic use in your jurisdiction? (In the EU and the US, the answer is currently no.) And what published, peer-reviewed, controlled clinical trial supports the specific claim being made?
We'll look at specific products — real serums on Belgian shelves, real clinic menus — in Part II. But the evidence needed to come first.
Because with exosomes, the biology is real. The products are a different story entirely.
Coming Next in Evidence vs. Marketing
Episode 4, Part II: Product Teardown — We'll open real exosome products available on Belgian shelves and in clinic menus. INCI lists, claims, prices, and what the evidence (if any) supports. If you have a product you'd like us to look at, let us know.