Why jurisdictions diverge
How the same product can be lawful in one country and not in another without either regulator being wrong, and why availability abroad proves nothing.
Regulatory frameworks classify by tests, and different jurisdictions use different tests, different definitions and different burdens of proof. The same vial can therefore be a regulated medicine in one country, a cosmetic ingredient in another, and unlawful to inject in a third, with all three positions internally consistent.
The practical consequence is that availability elsewhere establishes nothing about the position here. It is the most common argument offered in support of these products and it is not an argument about UK law at all.
Four reasons frameworks differ
Different definitions
What counts as a medicine, a cosmetic, a device or a biological product is defined in each jurisdiction's own legislation. Definitions overlap but do not match, and a product can fall inside one country's definition and outside another's on the same facts.
Different default positions
Some frameworks require pre-market authorisation for a category; others operate on notification with post-market surveillance. A product may be lawfully on sale in a notification regime without any assessment having occurred, which looks like approval and is not.
Different treatment of practice
The line between a regulated product and the practice of medicine is drawn differently in different places. Some frameworks give clinicians latitude to use materials in ways a product regulator has not assessed; others do not.
Different enforcement capacity
A framework that prohibits something and does not enforce it produces a market that looks permissive. Observing the market therefore tells you about enforcement, not about the rule.
The argument from elsewhere
The argument runs: this product is used widely in country X, therefore it is fine. It fails for several reasons at once.
- Country X may classify the product differently, so its lawful use there says nothing about classification here.
- Country X may not require pre-market assessment for that category, so use there does not mean assessment occurred.
- Country X may permit it in a clinical practice context that does not exist here.
- Use may be widespread and unlawful. Prevalence is not a legal argument.
None of this implies other regulators are wrong or that other countries are careless. It implies that regulatory conclusions do not travel, because they are conclusions about a framework rather than about the material.
A product used widely in other countries is therefore acceptable for use in the UK.
- Proposed mechanism
- Regulatory acceptance in one jurisdiction indicates the product is safe and appropriate elsewhere.
- What has been shown
- Frameworks differ in definitions, in whether pre-market assessment is required, in how the practice of medicine is treated, and in enforcement. Products can be lawfully marketed in a jurisdiction without any assessment of safety or efficacy having taken place there. Availability is therefore not evidence about assessment, still less about UK classification.
- Highest level reached
- Not shown
- Main confounders
- Marketing material often conflates availability with approval. Registration numbers from one regime are presented as approvals in another.
GradeNOT SUPPORTED
What would change thisNothing. The argument is a category error rather than a weak empirical claim. The relevant question is always what the position is here, under the framework that applies here.
Safety signals do travel, even when rules do not
One thing does cross borders usefully: adverse event information. If a regulator anywhere issues a safety communication about a category of product, that is information about the product rather than about the framework.
The United States Food and Drug Administration has issued public safety communication concerning exosome products, following reports of adverse events associated with unapproved preparations. We are citing the existence of that communication, which is a matter of public record, and not any figure from it. A reader who wants the detail should read it at source. The general lesson is that this category has produced real safety signals somewhere, which is a reason to take the questions in our sourcing section seriously rather than as paperwork.
| Information | Travels? | Why |
|---|---|---|
| Regulatory classification | No | It is a conclusion about a specific framework |
| Marketing authorisation | No | Granted by a specific regulator for a specific market |
| Availability on sale | No | Reflects framework and enforcement, not assessment |
| Adverse event reports | Yes | They are information about the product and its use |
| Published clinical evidence | Yes | Subject to the usual questions about design and population |
The importation question
Bringing a product into the UK is itself a regulated activity where the product falls within a regulated category, and lawful purchase abroad does not create a right to import, supply or use. This is a point on which practitioners are exposed if they have assumed that ordering from a foreign supplier sidesteps a domestic classification question. It does not, and it may add an offence rather than avoid one.
We state this at the level of principle only. Anyone in that position should take advice on their specific facts rather than rely on any published summary.
Why divergence is not a scandal
It is tempting to read divergence as evidence that one regulator is captured or another is obstructive. Usually it reflects genuine differences in how societies have chosen to balance access against assessment, and in the legal traditions those choices sit within.
The practical stance we would recommend is neither cynicism nor deference. Read the framework that applies where you are, apply its tests to the product in front of you, and treat claims about other jurisdictions as background rather than as evidence. That approach costs nothing and it survives the next regulatory change, which is more than can be said for most confident statements in this sector.
Questions readers ask
Why is the same product legal in one country and not another?
Because frameworks classify by different tests and definitions, require assessment at different points, treat the practice of medicine differently, and enforce differently. All three positions can be internally consistent.
Does availability abroad mean a product is safe?
No. Some frameworks allow products onto the market without pre-market assessment, so availability may mean only that a notification was made. Availability is information about a framework, not about a product.
Does anything cross borders usefully?
Yes. Adverse event reports and published clinical evidence are information about the product and its use rather than about a legal framework, so they remain relevant wherever you are.
Have regulators issued safety communications about exosome products?
Public safety communication concerning exosome products has been issued in at least one major jurisdiction following reports of adverse events with unapproved preparations. That communication is a matter of public record and should be read at source.
Can I import a product that is legal where it is sold?
Importation is itself regulated where the product falls within a regulated category, and lawful purchase abroad does not create a right to import, supply or use. Anyone in that position should take advice on their specific facts.