How far exosome preparations have actually been verified

This article has to begin with the terminology. It is something rarely discussed elsewhere, and everything else hangs on it.

Cells release very small sacs to the outside. Collectively these are called extracellular vesicles (EVs). Among them, those formed in and released from the multivesicular body inside the cell are called exosomes. In other words, an exosome is one branch of the extracellular vesicles, and the criterion that distinguishes it is “where it was made”.

Here is the problem. MISEV2023, the most recent guideline issued in 2024 by the International Society for Extracellular Vesicles (ISEV), puts it like this.

“ISEV recommends use of the generic term ‘EV’ and its operational extensions, instead of inconsistently defined and sometimes misleading terms such as ‘exosomes’ and ‘ectosomes’.”

In the glossary of the same guideline, the entry for ‘exosome’ reads as follows — “Discouraged unless subcellular origin can be demonstrated.”

Why should that be? The guideline sets out the reason as well.

“Most EV separation techniques do not selectively enrich EVs generated by different mechanisms, and definitive characterisation of subtypes on the basis of biogenesis is also difficult. There are no universal molecular markers of ectosomes, exosomes or other EV subtypes.”

Put together, it comes to this. To say of some material that “this is an exosome” you would have to demonstrate that it came from a multivesicular body, and there is no universal marker by which to tell. That is why the society says not to use the word.

The same guideline is careful about size too. It defines small extracellular vesicles operationally as “under 200nm” as a rule, but states explicitly that “the measured diameter depends on the method of characterisation”. In other words, change the way you measure and the number changes.

We too will go on writing ‘exosome’ in this article, for convenience, because that is what the market calls it. But please read it bearing in mind that strictly these are extracellular vesicles, and there is as yet no way to verify whether that name is accurate.

This part is in practice the most important.

Korea permits the use of human cell · tissue culture fluid as a cosmetic ingredient, conditionally. Separate safety standards for it are laid down in the Regulation on Safety Standards for Cosmetics. As a result a great many cosmetics claiming to contain exosomes are distributed in Korea.

This differs from country to country. The table below is what we verified through regulatory analysis material.

The same product cannot be used as a cosmetic in Europe and is a cosmetic in Korea. This does not mean the product is good or bad; it means that “it is sold as a cosmetic” is not evidence of safety or of efficacy. The regulatory threshold simply differs from country to country.

Korean regulators are aware of this situation too. In the National Assembly's audit of government agencies in 2022 it was pointed out that “among the substances injected into the skin as skin booster injections, exosomes were registered with the MFDS as cosmetics”.

Here we come to the core of this article.

A cosmetic is defined as something applied or sprayed on. Putting it inside the skin is not a cosmetic's method of use. That is precisely the substance of the notice the MFDS issued on 5 January 2023.

For purposes such as skin regeneration · wrinkle improvement, only products approved as medicines or as medical devices may be injected into the skin. The MFDS stated that “injection into the skin using a syringe or a microneedle is possible only with medicines · medical devices”, and that it would respond strictly to advertising · distributing unapproved products as though they could be injected.

Note that “microneedle” is specified. Methods that push the material in with microneedling equipment rather than a syringe are also covered by this notice.

The court's decision

And there has been an actual case.

The last line matters especially. What is looked at is the act itself, not whether the outcome was good. The decision is that unlawfulness is made out even where there were no adverse effects.

That is why Miso Clinic uses this preparation only for application to the surface of the skin immediately after a laser treatment, and does not put it into the skin with a syringe or a microneedle. This is not because we are being cautious but because that is as far as the approved scope of use currently extends in Korea.

And, as you will see below, the condition actually tested in people was precisely that too.

In the field of aesthetic dermatology the human clinical evidence for exosomes is far thinner than one might think. A systematic review published in 2026 screened 1,032 papers and included 21, and among those only 1 was a randomised controlled trial.

We set out the best-designed trial as it stands.

Reading this table honestly, five points have to be made.

• It was applied, not injected. It was put on the skin immediately after the laser
• It is not a trial of exosomes alone. Since it was a condition combined with laser, the effect of the exosomes on their own was not isolated
• The control side improved by 19.9% too. A substantial part of the improvement is the laser itself. What the exosomes added is the difference (about 12.6 percentage points)
• The sample size was not set by a power calculation. The paper itself states that “in the absence of previous data it was determined on the basis of feasibility”
• Follow-up is 12 weeks. There are no data on long-term durability or long-term safety

The interests involved are also recorded in the paper — the exosome solution and the control solution used in the trial were manufactured · purified and supplied by the manufacturer. The authors declared no conflict of interest, but the fact that the material was supplied is stated. The limitations the authors themselves gave were that “the ethnic background of the participants was all similar” and that “follow-up studies are needed to find the optimal application regimen”.

Even so, this trial is the best data in the field. And the condition this trial verified — topical application immediately after fractional laser — is the same as the way Miso Clinic uses this preparation. That we use it only as a topical application is not only because of the law but also because that is the only thing that has been tested.

You will see something recurring across the whole table. The samples are small, the follow-up is short, and most are conditions combined with another procedure. And there is no trial showing what they do on their own.

One more thing — it is worth remembering that the conclusion of the photoageing trial was “similar to PRP”, not “superior to PRP”. It comes up again below.

On this subject an unusual number of unverified sentences circulate. We looked for them one by one.

And — is the preparation studied the same as the product sold

On this question, we could not find literature saying “they are the same”, and there was a good deal of literature warning that “they may differ”.

• A 2025 dermatology review: “Because of the limitations of current isolation and profiling techniques, it is difficult to assess the contents of exosomes and to compare products with one another.”
• A 2026 systematic review: “Inconsistent isolation methods, variability in exosome quality, and the absence of standard protocols.”
• The material used in the 25-subject trial above was manufactured · purified and supplied by the manufacturer for research use, and nowhere in the paper is there any statement that it is identical to a marketed product

So there is no basis for transposing the results of one paper onto another product. Between “this result came out of exosome research” and “this product produces that effect”, no bridge has yet been built.

On 6 December 2019 the US FDA issued a public safety notification on exosome products. What can be verified in the original text is as follows.

• “There are currently no FDA-approved exosome products.”
• Exosomes used to treat diseases · conditions in humans are regulated as drugs and biological products and are subject to prior review · approval
• There had been “multiple recent reports of serious adverse events” experienced by patients in Nebraska treated with unapproved products claiming to contain exosomes

There is something we should say honestly here. We could not find a primary document specifying the number of patients · the symptoms · the causative organism in this incident. We checked all three FDA documents, the advisory from the Nebraska health authorities and the US CDC archive page, but “multiple reports” was all there was. The specific numbers circulating on the internet appear to be numbers from a different incident of the same period (an outbreak of infections associated with an umbilical cord blood-derived stem cell product) mixed in, but we will not state it as fact. We will not repeat numbers we have not verified.

There is one further thing that is verified. In September 2023 the FDA sent a warning letter to a leading exosome company. It stated that the products in question constituted unlicensed biological products and that there were violations of manufacturing standards, including failure of aseptic process validation.

The problem raised in the United Kingdom

In March 2025 it was reported that aesthetic clinics in the United Kingdom were using prohibited human-derived exosome products. The observation of a cell biology researcher at the University of Cambridge was quoted.

“These are human biologics and there is a risk of disease transmission. And there is no reliable way to separate exosomes from viruses.”

That report did not present quantitative data, such as how many products were tested. Please read it as an observation in character. For reference, a 2025 dermatology review recorded the same concern — “improperly manufactured exosomes may carry microorganisms such as viral proteins or mycoplasma and cause infection, and other cellular contents may provoke an immune response.”

We cannot give you an answer to this question. That is because we could not find an official tally.

In the National Assembly's audit of government agencies in 2022 there was a mention that cases of adverse effects such as inflammation · scarring had been received by the Korean Dermatological Association · the Korea Medical Dispute Mediation and Arbitration Agency · the Korea Consumer Agency. However, we could not verify any official material presenting the number of cases.

Expert warnings are verifiable. There were observations that when a cosmetic is injected into the body it can cause serious adverse effects such as sepsis, including skin discoloration · skin necrosis from a local inflammatory reaction, and observations about infection risk · bruising · oedema · allergic reaction.

You must not read “there is no tally” as “there are no adverse effects”. It means that they are not tallied and published. And this point is if anything the important one — treatments are being performed widely in a state where nobody knows the size of the risk.

To sum up, our way of using it is as follows.

• We apply it to the surface of the skin immediately after a fractional laser treatment. This is the same as the condition the 25-subject double-blind split-face study verified
• We do not put it into the skin with a syringe or a microneedle. This is because no exosome preparation approved in Korea for injection has been verified, and because in a case where that was done the court held that a suspension of licence was justified
• We do not recommend it as a stand-alone treatment. There is no trial showing an effect on its own in humans
• We do not describe it with words like “regeneration” or “treatment”. Those expressions exceed the scope of efficacy of a cosmetic, and the evidence has not been verified to that degree either
• We do not promise expectations as numbers. In the trial above, what the exosomes added was about 12.6 percentage points at the 12-week point, and that was with the laser as well

We are not telling you that exosomes are “something you should not have”. Under the condition of topical application immediately after laser there are data showing a better result than the control, and under that condition no safety problem was reported either. But once you step outside that condition the evidence disappears, and the moment it goes inside the skin the legal domain changes.

Reduced to one sentence, it comes to this. Exosomes are a material whose name, whose composition and whose effect are all as yet undetermined, and what has been verified so far is one small trial showing that “applied immediately after laser, it was a little better than the control”. That is the reason we use it within exactly that scope and no further.

Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. Every study cited above is given together with its design, its size and the limitations the authors themselves recorded, and where we could not find data, we have said that we could not find any.