Topical or injected exosomes: why the route changes the question

Two clinics can quote the same product, the same number of sessions and a similar price while planning to do materially different things with it. The difference is the route. This page sets out what each route physically does, what rules attach to it, what it changes about risk, and the language that tends to hide the distinction.

The three routes, described plainly

Onto intact skin. The preparation is applied as a serum and nothing is done to breach the barrier. The outer layer of skin is a highly effective barrier to particles of this size, and the reasonable expectation is that almost none of the material reaches living tissue. What you are buying at that point is a topical cosmetic, and it should be priced and described as one.

After microneedling. A needling device creates thousands of temporary channels through the barrier, and the preparation is applied to that surface immediately afterwards. Material now has a physical route into living tissue. This is the route used in most UK clinics offering the treatment, and it is the one our main guide describes.

By injection. The preparation is placed into the dermis or the subcutaneous plane directly with a needle or cannula. Delivery is no longer in question. Everything else is, because the material is now unambiguously being administered into the body as though it were a medicine.

Why the rules change with the route

Which framework applies to a preparation depends on what it contains, how it is presented and what is claimed for it, and the route of administration is central to all three. A product presented for application to the surface of the skin for a cosmetic purpose sits in the territory of cosmetic product rules. A product administered into the body with a claim to treat, prevent or modify a physiological function sits squarely in the territory of medicines regulation, which is administered in the United Kingdom by the Medicines and Healthcare products Regulatory Agency. Where the material is of human origin, rules on the handling and traceability of human tissue can apply as well, and the Human Tissue Authority licenses establishments that carry out those activities.

The practical consequence for a reader is simple. No exosome product holds a UK marketing authorisation as an injectable medicine for any aesthetic or hair indication. Unlicensed does not mean tested and rejected, and it is not the same as banned. It means the independent assessment of quality, safety and efficacy that produces a licence has not been completed for this use, so there is no dossier for anyone to point you at and no defined product recall route of the kind a licensed medicine has. Our regulation page works through the overlapping frameworks in full, and the position should be checked with the regulator directly rather than taken from any clinic website, this one included.

What the route changes about risk

Risk in this treatment separates cleanly into two sources, and the route determines how much of each you take on.

The preparation risks are described as unquantified rather than low for a specific reason. These products are not standardised between manufacturers, and there is no systematic UK collection of adverse events for them in cosmetic use. An absence of published harm in a field with no reporting system is not evidence of safety. It is an absence of information.

The claims each route can support

A useful discipline is to ask what the route makes physically possible before assessing what is claimed. If the plan is application to intact skin, then any claim that depends on material reaching the dermal papilla or the dermis is claiming something the route does not deliver. If the plan is microneedling plus application, the claim is a combined one, and it cannot be attributed to the preparation alone without a study design that separates the two. Our guide to reading study designs covers exactly that separation and why it is so often missing.

Advertising rules bear on this too. Marketing claims for treatments in the United Kingdom are subject to the advertising codes enforced by the Advertising Standards Authority, which require claims to be capable of substantiation. A claim that a treatment regenerates, repairs or restores tissue is a claim about the body, and the question of whether the route can even deliver the material is a fair part of assessing it.

The language that blurs the distinction

Consultation language tends to collapse the routes into one another. Watch for these.

• Infused, driven in, pushed in. These describe an intention rather than a route. Ask what device breaches the barrier, to what depth, and whether the preparation goes on before, during or after.
• Needle free. Usually accurate and usually meaningful, because it typically means the barrier is not being breached in the way microneedling breaches it.
• Mesotherapy, microinjection, nappage. These are injection techniques. If any of them is described, the plan is injection, and the licensing question above applies directly.
• Cocktail, blend, protocol. Words that describe a mixture without saying what is in it. Ask what else is being combined, because the answer changes both the risk and the regulatory picture.

What to ask, in order

1. Which route is planned for me, in those terms: on the skin, after needling, or injected?
2. If needling is used, at what depth, and is the preparation applied during or after the passes?
3. What is the product, who supplies it, and under what classification is it supplied?
4. Is anything else being mixed with it, and if so what?
5. Who will carry out the treatment, and what is their professional registration?
6. What happens if I have a reaction, and who do I contact out of hours?

The twelve consultation questions take this further and are designed to be printed and written on. A clinic that answers the route question precisely and without irritation is demonstrating something useful about how it works.

What this page does not cover

This page compares routes of administration. It does not compare products, name any preparation or assess any manufacturer, and it does not cover the biology or manufacture of vesicles, which sits with the extracellular vesicle literature rather than with a patient guide. It does not tell you whether a treatment is suitable for you, which requires a practitioner who has examined you. It is not medical advice, and the regulatory position described here can change, so check it at source.

Common questions

Is injecting exosomes illegal in the UK?

The accurate statement is narrower than legal or illegal. No exosome product holds a UK marketing authorisation as an injectable medicine for aesthetic or hair use, so there is no licensed injectable route. What follows from that in a given case depends on the product and how it is supplied, which is why the classification question is worth asking directly.

Does a topical exosome serum do anything?

It behaves as a cosmetic applied to the surface. Particles of this size do not cross intact skin in useful quantity, so any benefit is more likely to come from the base the product is formulated in than from the vesicles themselves.

Is microneedling plus a preparation better than microneedling alone?

That is the open question, and it is open because the study design needed to answer it, needling plus preparation against needling plus an inert vehicle, is largely missing from the literature.

Why do clinics use microneedling rather than injection?

Partly because it delivers material through a barrier that would otherwise exclude it, and partly because injection raises the licensing question in its sharpest form. Both reasons are worth understanding before you agree to either.

Should the preparation be applied during or after needling?

Practice varies and there is no established standard, which is itself worth knowing. The useful part of asking is that it tells you whether the clinic has a protocol it can describe.

Does a deeper needling depth mean a better result?

Not reliably, and depth increases the risk from the needling itself. Depth is a clinical decision for the area and the skin in front of the practitioner, not a dial to be turned up on request.

If you want to speak to someone

We are not a clinic and we give no medical advice. If you would like to, we can pass your details to a registered UK practitioner who will contact you directly. Nothing is booked on your behalf and there is no obligation. Read the regulation page first.

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Read next

• Risks and the UK regulatory positionThe overlapping frameworks, worked through properly
• Exosomes for skin qualityWhere the same attribution problem shows up on the face
• Twelve reasons to decline a treatmentThe refusal criteria, in a form you can take with you