Borderline products and the MHRA
How the medicines definition works through presentation and function, why marketing claims can change a product's classification, and how to apply the test yourself.
A product is a medicinal product in UK law if it meets either of two tests. By presentation: it is presented as having properties for treating or preventing disease. By function: it is administered with a view to restoring, correcting or modifying physiological functions by pharmacological, immunological or metabolic action, or to making a medical diagnosis.
Either limb is sufficient. This has a consequence that suppliers underestimate: what you say about a product can make it a medicine. A preparation sold as a cosmetic can be pulled into the medicines framework by the claims made in its marketing, and the MHRA publishes guidance specifically on how it approaches these determinations.
The definition, in two parts
The medicines definition in UK law is deliberately broad, and it captures products by two independent routes.
Presentation
A product presented as having properties for treating or preventing disease in human beings is a medicinal product. This limb is about how the product is put before the public: labelling, packaging, advertising, what the seller says, and reasonably what an averagely well informed consumer would take from it. A product with no pharmacological activity at all can be caught by this limb if it is presented as a treatment.
Function
A product administered with a view to restoring, correcting or modifying physiological functions by exerting a pharmacological, immunological or metabolic action, or to making a medical diagnosis, is a medicinal product. This limb is about what the product does and how it does it, assessed on the available evidence.
Why the presentation limb catches people out
Suppliers frequently assume that classification is fixed by what the product contains. It is not. Two identical vials, one sold as a cosmetic serum and one sold as a treatment for a named condition, can be classified differently because the second has been presented as a medicine.
This is why marketing copy is a regulatory document, not a creative one. Phrases describing a product as treating a condition, repairing tissue, or acting on cells to modify their function are moving the product towards the medicines definition on one limb or the other. The MHRA borderline guidance sets out how these determinations are approached, and it is worth reading in full by anyone writing product claims.
A product's regulatory classification is determined by what its supplier calls it.
- Proposed mechanism
- Labelling a product as a cosmetic or as research material places it outside the medicines framework.
- What has been shown
- The medicines definition operates through presentation and function tests. The presentation limb assesses how a product is put before the public, and the function limb assesses what it does. Neither turns on the label a supplier prefers, and the presentation limb specifically can capture a product on the strength of claims made for it.
- Highest level reached
- Not shown
- Main confounders
- Enforcement practice varies and inaction is not endorsement. Determinations are product specific and fact specific, so an outcome for one product does not settle another.
GradeNOT SUPPORTED
What would change thisNothing about the framework. This is how the definition is constructed. A supplier who believes their product sits outside it should be able to explain which limb it fails and why, and that explanation is a reasonable thing to ask for.
Applying the test to this category
Take a vesicle preparation marketed for skin and consider the two limbs.
Presentation. Does the marketing claim it treats a condition? Scarring, hair loss and inflammatory skin conditions are conditions. Claims about improving the appearance of skin sit further from the line than claims about treating a named disorder. The distinction between improving appearance and treating a condition is exactly where a great deal of copy in this sector operates.
Function. Is the product administered with a view to modifying physiological functions by pharmacological, immunological or metabolic action? The mechanistic claims made for these products, that they deliver signalling molecules which alter cell behaviour, describe precisely such an action. A supplier arguing the product is not a medicine while claiming it signals cells to increase matrix production is arguing against their own marketing.
| Claim type | Example wording | Limb engaged |
|---|---|---|
| Appearance | Improves the look of skin texture | Neither, on its face |
| Condition | Treats acne scarring | Presentation |
| Mechanistic | Signals fibroblasts to produce collagen | Function |
| Comparative medical | An alternative to a prescribed treatment | Presentation |
| Restoration | Repairs damaged tissue | Both, arguably |
Devices, cosmetics and the other borders
The medicines border is not the only one. A product achieving its principal intended action by physical means may fall within the medical devices framework rather than the medicines framework, and the boundary between the two is itself a borderline question. Cosmetics have their own definition and their own restrictions. The MHRA guidance addresses these boundaries because the boundaries are where the difficult cases live.
For a reader, the practical point is that these regimes are not a menu. A product has a classification determined by its characteristics and presentation, and a supplier asserting one does not make it so. Claims that a product is registered, notified, certified or compliant should always be followed by the question: under which regime, and for what.
What the regulator can do
Where the MHRA determines a product is a medicinal product placed on the market without an authorisation, it has enforcement powers. Determinations are made case by case on the specific facts, and the agency operates a route for asking about a specific product's status. That is a better source than any general article, including this one.
It is also worth knowing that adverse events involving medicines and medical devices in the UK can be reported through the Yellow Card scheme, including by members of the public. A category operating largely outside authorisation generates little safety data by design, and reporting is one of the few mechanisms that produces any.
Why this article exists
Because the commonest confident statement in this sector, that a product is not a medicine because it is sold as a cosmetic, is not how the test works, and the error is easy to correct. Understanding the two limbs takes ten minutes and it changes how you read every product page in the category. That is the kind of thing a science desk should be useful for.
Questions readers ask
What makes something a medicinal product in the UK?
Either of two tests. Presentation: it is presented as having properties for treating or preventing disease. Function: it is administered with a view to restoring, correcting or modifying physiological functions by pharmacological, immunological or metabolic action, or to making a diagnosis. Either limb is sufficient.
Can marketing claims change a product's classification?
Yes. The presentation limb assesses how a product is put before the public, so claims made in marketing can bring a product within the medicines definition regardless of the label the supplier prefers.
If a product is sold as a cosmetic, is it outside the medicines framework?
Not necessarily. Classification follows from the product's characteristics and presentation rather than from the supplier's chosen description. A cosmetic label does not settle the question.
Do mechanistic claims matter?
They can engage the function limb directly. A claim that a product acts on cells to modify their behaviour describes precisely the kind of action the functional definition covers.
Who decides a specific product's status?
The MHRA makes determinations case by case on the specific facts and operates a route for enquiries about a particular product. That is a more reliable source than any general summary.