Topical finasteride: what is actually available in the UK, and what gets absorbed

This page is medicine information rather than an advert. Finasteride in any form is a prescription only medicine in the UK ^[6], and whether it is suitable is a decision for a prescriber after an assessment.

Topical finasteride is usually presented as the same treatment without the drawbacks. The reasoning is intuitive — put the drug where the follicles are and keep it out of the bloodstream — and the published data show it is partly, but only partly, true.

What exists, and where

The product behind most of the evidence is P-3074, also known as ALM12845: a finasteride 0.25% spray solution developed by Polichem and licensed to Almirall. A marketing authorisation application was filed with the EMA in September 2019, and it reached market through national licences and partners — as Caretopic in Italy and parts of Western Europe, and as Finjuve in the Middle East and North Africa and in South Korea.

There is no MHRA-licensed topical finasteride product in the UK ^[5]. Everything prescribed here is one of three things: an unlicensed “special”, a compounded preparation, or an import.

That matters more than it sounds. A special is prepared to meet an individual patient’s needs where no licensed product is suitable. UK rules governing specials are tight and the MHRA regulates the manufacturers, but a special has not been through the assessment of quality, safety and efficacy that a licence represents, and the consistency you get from a licensed production line is not guaranteed in the same way. The US FDA issued warnings during 2025 about compounded topical finasteride products and adverse event reports associated with them, which is the same concern from a market where compounding is far less controlled.

One further point of accuracy, because it appears widely: a licensed finasteride and minoxidil combination topical is not available in the UK, and we have not been able to verify a licensed combination product in the EU either. Treat any claim that you are being supplied a licensed combination as something to check rather than accept.

What the absorption data show

The phase III programme included 458 participants and measured the thing everyone wants to know ^[1].

Peak plasma finasteride concentrations were more than 100 times lower with the topical spray than with the 1mg tablet. That is a genuinely dramatic reduction in exposure.

But mean serum DHT fell by 34.5% with the topical spray, against 55.6% with the oral tablet ^[1].

Those two figures sit together awkwardly, and the second is the one that matters clinically. Despite plasma drug levels two orders of magnitude lower, the topical route still produced roughly two-thirds of the oral effect on circulating DHT. The drug is absorbed; the DHT suppression it causes is systemic, not confined to the scalp.

The efficacy result was that the 0.25% spray was non-inferior to oral finasteride 1mg on target-area hair count and superior to vehicle ^[1].

Non-inferiority is a specific claim and worth reading carefully. It means the trial was designed to show the topical was not worse than the tablet by more than a pre-specified margin, over the trial’s duration, on that particular measure. It is not a demonstration that the two are identical, and it says nothing about how they compare over the years a treatment like this is actually taken.

What that means for side effects

If serum DHT is suppressed, the mechanism that produces the sexual and psychiatric effects associated with oral finasteride has not been switched off. It has been reduced.

A 2026 pharmacovigilance study in the International Journal of Dermatology examined whether topical finasteride’s safety profile genuinely differs from oral in adverse event reporting data ^[2]. The findings indicate that adverse event reports of the same types do occur with topical use. That does not establish a rate — spontaneous reporting databases have no denominator and cannot measure incidence — but it directly undercuts the marketing claim that topical finasteride is free of systemic side effects.

The honest framing is: lower systemic exposure, a plausible expectation of fewer systemic side effects, and no basis for saying there are none. The UK safety position set out in the May 2026 Drug Safety Update — that finasteride is associated with depression, suicidal ideation and sexual dysfunction which may persist after treatment is stopped ^[4] — is about the active substance, and a prescriber assessing anyone for a topical formulation should be having the same conversation. Finasteride side effects covers that in full.

There are also route-specific effects. Scalp irritation, itch and contact dermatitis are reported with topical preparations, and depend heavily on what the finasteride has been dissolved in — a familiar problem from minoxidil side effects, where the vehicle rather than the drug is usually the culprit. With a compounded preparation, the vehicle is not standardised between suppliers, so a reaction to one formulation does not necessarily predict a reaction to another, and nor does tolerance of one predict tolerance of the next.

Pregnancy precautions still apply

This is the point most likely to be got wrong, and the consequences are the most serious.

Oral finasteride is contraindicated in pregnancy and in women of childbearing potential because inhibiting the conversion of testosterone to DHT risks abnormalities of the external genitalia, specifically hypospadias, in a male foetus ^[3]. Because topical application produces measurable systemic absorption and about 34.5% serum DHT suppression, that theoretical risk is reduced but not eliminated.

The topical route then adds a hazard the tablet does not have. A coated tablet in a blister keeps the active ingredient away from anyone else’s skin. A solution sprayed onto a scalp does not. Transfer can occur by direct skin contact with the treated scalp, from hands, or via a pillowcase.

Practically: women who are or may become pregnant should not handle the product and should not contact the application site. Apply it yourself, wash your hands immediately, allow the scalp to dry fully before contact with anyone, and think about shared bedding. None of this is theoretical fuss; it is the reason the topical route needs more handling care than the tablet, not less.

How to think about it

Topical finasteride is a reasonable idea supported by a decent phase III trial, sold in the UK in a form that has not been licensed here, with a systemic effect its marketing frequently denies.

If it is being considered, the useful questions are what exactly is being supplied and by whom, what concentration and what vehicle, whether the supplier is properly regulated, and whether the prescriber has covered the same safety ground they would for the tablet. Finasteride explained sets out what the oral medicine does, and dutasteride for hair loss covers the other off-label direction people take when the standard option has not suited them.

This article is for general information and isn’t a substitute for advice from your own clinician. If you feel unwell, contact your GP or NHS 111. In an emergency, call 999.