Topical finasteride: is it safer than the pill?
Topical finasteride still reaches your blood: in a trial, a spray cut blood DHT by 34.5%. Most of 32 FDA reports said symptoms continued after stopping.
A finasteride spray puts far less of the drug into your blood than a tablet. Less is not none. In a 24-week trial, the spray still cut DHT, the hormone finasteride lowers, by 34.5% in the blood. The US regulator, the FDA, received 32 reports of side effects from pharmacy-mixed topical finasteride. Most said symptoms continued after stopping.
Does topical finasteride get into your blood?
Yes. The FDA says that absorption through the skin into the bloodstream is expected.
Finasteride blocks the step that turns testosterone into DHT. The UK regulator, the MHRA, explains that tablets lower DHT in the scalp and in the blood. A spray is meant to work on the scalp. The question is how much travels further.
A trial of 458 men aged 18 to 40 measured this. It compared a 0.25% finasteride spray with the 1 mg tablet and a placebo for 24 weeks. The drug companies Almirall and Polichem paid for it.
Two results matter. Peak finasteride levels in the blood were more than 100 times lower with the spray. Yet DHT in the blood still fell by 34.5%, against 55.6% with the tablet and no change with placebo.
So a spray lowers blood DHT less than a tablet, but it still lowers it. How much the skin takes in also varies, which a 2025 analysis says needs more study.
Is a lower dose or strength safer?
A smaller amount lowers blood DHT less. But no amount tested left it unchanged.
In a one-week study of 32 men with hair loss, four groups put different amounts of a 0.25% finasteride solution on the scalp once a day. A fifth group used the liquid without the drug. At the two smallest amounts, DHT in the blood fell by 24% and 26%. At the two largest, it fell by 44% and 48%.
Fall in blood DHT after one week of a finasteride solution
The other part of that study tested much larger amounts: 1 mL, once or twice a day. Blood DHT fell by 60-70%, a range that also covered the men taking the tablet.
The products you are offered may not match the ones in these studies, which contained 0.25% finasteride on its own. In 2025, the US telehealth service Hims & Hers prescribed a 0.3% finasteride spray with 6% minoxidil, at four sprays once a day.
The FDA’s warning does not name a safe strength. It covers compounded finasteride for the skin, alone or mixed with other drugs such as minoxidil.
What did the FDA warning say?
In April 2025 the FDA warned prescribers, pharmacies and the public about compounded topical finasteride. Compounded means mixed by a pharmacist or doctor for one patient, rather than made as an approved medicine.
- Reports
- 32, sent to the FDA between 2019 and 2024
- Symptoms
- Erectile dysfunction, low libido, testicular pain, anxiety, depression, suicidal thoughts, brain fog, fatigue, insomnia
- After stopping
- Most reports said the symptoms continued
- On the skin
- Irritation, redness, dryness, scaling, stinging, burning
The FDA also reported what people told it. Some had not known these side effects were possible. Others said a prescriber had told them there was no risk because the product was topical.
Thirty-two is a count of reports, not a rate. The FDA says reports like these cannot be used to estimate how often an event happens. A report on its own also does not prove that the drug caused it.
Is topical finasteride FDA-approved?
No. In the US, no finasteride product for the skin is FDA-approved. The FDA does not check compounded drugs for safety, effectiveness or quality before they are sold.
The EU is different. Finasteride sprays are authorised in several EU countries for men aged 18 to 41 with early hair loss. So “topical finasteride” can mean a licensed spray or a pharmacy mixture.
Can topical finasteride cause erectile dysfunction?
Erectile dysfunction has been reported after using compounded topical finasteride. It is among the symptoms in the FDA’s 32 reports, along with low libido.
In the 24-week trial, sexual side effects recorded as treatment-related were reported by 2.8% of men on the spray. The figure was 4.8% on the tablet and 3.3% on placebo. That puts the spray close to placebo over 24 weeks.
But the trial’s last check came four weeks after treatment ended. It did not follow people for months or years.
A 2025 analysis of US safety reports looked for warning signals of the sexual and mental health symptoms seen in post-finasteride syndrome (PFS). It found signals with topical finasteride too, though fewer than with tablets. Its authors say stress and other causes may explain some of those reports.
Can side effects continue after stopping topical finasteride?
The FDA says most of its 32 reports described symptoms that continued after stopping. When symptoms like these last after stopping finasteride, patients call it PFS. What happens when you stop taking finasteride covers what the labels say about that.
Sawyer used topical finasteride for three months. His story says the effects continued after he stopped.
Gary also used topical finasteride, and describes side effects that continued after he stopped.
None of the studies above can say how often this happens. A study of 638,629 men prescribed compounded finasteride by Hims & Hers, written by company staff and advisers, asked one yes-or-no question about side effects, about 130 days after people started. Only 23.7% answered, and 2.7% of them said side effects bothered them.
Answering that needs people followed for months or years, including after they stop. The SIDEfxHUB registry records a person’s experience over time, which a one-off side effect report cannot.
MedDRA code 10082430
English term: Post 5-alpha-reductase inhibitor syndrome
Use it if symptoms continued after topical finasteride, finasteride tablets or dutasteride. Write the exact wording in the free-text box, then describe what happened in your own words, and say whether you used it on the skin or as tablets. Our reporting guide shows how to report in the UK, the US and other countries.
Is topical finasteride safe around a pregnant partner?
The FDA says topical finasteride may expose other people more easily than tablets do, especially women. That matters in pregnancy. Finasteride may cause abnormalities in a male baby, which is why women are told not to handle crushed or broken tablets. Whole tablets have a coating that prevents contact. Finasteride on the scalp has none, and the FDA asks prescribers to explain this risk.
What have European and UK regulators found?
The EU’s review looked at finasteride sprays as well as tablets. In 2025 it confirmed suicidal thoughts as a side effect of finasteride tablets. It found no evidence linking suicidal thoughts to the sprays. The review was about suicidal thoughts and behaviour, so that finding covers those only.
In the UK, the MHRA announced a warning card for every finasteride pack in 2024. It also noted reports of sexual side effects continuing after people stopped. The review behind that decision looked at tablets and did not discuss sprays. In May 2026 the MHRA strengthened the warnings for finasteride 1 mg. Every dated step, in the UK, the EU and the US, is in finasteride warnings from the MHRA, EMA and FDA.
What regulators have done about finasteride since 2024
What we cannot tell you
We cannot tell you your own risk, or whether topical finasteride is right for you. That decision belongs to you and a prescriber who knows your history.
The evidence supports a smaller claim. Topical finasteride reaches the blood and lowers DHT there, and people have reported symptoms that continued after stopping it.
If that has happened to you, you can report it through the Yellow Card scheme in the UK or MedWatch in the US. A report records one reaction. The registry also records what happens to you afterwards, which is what researchers need.
Questions to ask before you start
- Is this a licensed product, or compounded? In the US, compounded topical finasteride is what the FDA warned about.
- How much finasteride will I apply each day? Ask for the strength and the number of sprays.
- What else is in it? Some sprays also contain minoxidil.
- Can side effects continue after stopping? Some people told the FDA they wished they had been told.
- Who do I contact if my sex drive, erections or mood change?
- How do I avoid exposing a partner who is or could become pregnant?
Do not stop or change a medicine because of anything on this page.
If you use topical finasteride or tablets and something has changed, tell the person who prescribed it and decide the next step together. If your mood has dropped or you have thoughts of suicide, speak to a doctor as soon as you can.
If you are struggling with your mental health, the Samaritans are on 116 123 in the UK, free, at any hour. In the US, call or text 988.
This information does not replace medical advice. Talk to your doctor before you make any decision about your treatment.
550+ people have joined the registry.
Join them, then report your side effects.
- Put your condition on the record
- Be first to hear about studies you can join
- Then report your side effects to your regulator