Topical finasteride aims to block follicle DHT locally. Evidence is promising in studies, but products are mostly compounded or licensed outside the US, and systemic absorption is not zero.
Oral finasteride 1 mg is FDA-approved for male pattern hair loss. Rub-on finasteride is a different regulatory story: in the United States it is not approved as a monotherapy topical for that indication, even though compounding pharmacies and some overseas brands sell lotions, gels, and sprays, sometimes mixed with minoxidil. The idea is higher scalp, lower blood drug levels. Trials and pharmacokinetic papers suggest DHT can fall in the scalp with smaller average serum changes than tablets — not the same as ‘no systemic effect’ and not the same as a standardised OTC bottle. Concentrations and vehicles vary wildly, so Instagram ‘0.1% stacks’ are not interchangeable.
Sexual side effects appear less often in some topical series than in oral data, but they are still reported, which fits leftover absorption. Household pregnancy warning remains: finasteride can harm a male fetus. Partners who may be pregnant should not handle the product carelessly; men using it should talk to a clinician about exposure. Do not assume topical is safe in women — that is a specialist decision, not a loophole. Quality control of compounded liquids is uneven. If you want this route, use a licensed prescriber, not a research chemical site. This is not medical advice.
よくある質問
Is topical finasteride FDA-approved for baldness?
Oral finasteride 1 mg is FDA-approved for male pattern hair loss. A standalone topical finasteride product is not the US FDA-approved standard for that use. Other countries may license different topicals; that is not a US OTC green light.
Can topical finasteride still affect hormones in the blood?
Yes. Absorption is usually lower than tablets on average, not zero. That is why side-effect and pregnancy conversations do not disappear just because the drug is a lotion.
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