Finasteride
Reviewed by Kate · Last updated 6 May 2026
An oral medication that addresses hair loss by reducing DHT production in the scalp
Best For Skin Types
All
Addresses
Usage Frequency
Daily
What Is Finasteride?
Finasteride is a pharmaceutical compound that works as a type 2 5-alpha-reductase inhibitor. It is taken orally and is most commonly known by its brand names Propecia (lower dose) and Proscar (higher dose). Rather than a cosmetic ingredient applied topically, finasteride is a systemic medication that circulates through the body to target hair follicles.
The drug functions by blocking an enzyme responsible for converting testosterone into dihydrotestosterone (DHT), a hormone implicated in androgenetic alopecia (male and female pattern hair loss). By reducing DHT levels, particularly at the scalp, finasteride aims to slow hair loss progression and, in some cases, stimulate regrowth in affected areas.
How It Works
Androgenetic alopecia involves a process where DHT causes hair follicles to miniaturise—becoming progressively smaller and producing thinner, shorter hairs. Finasteride blocks the enzyme 5-alpha-reductase type 2, which is responsible for converting testosterone into DHT. Research shows that even low oral doses significantly reduce DHT levels at the scalp: studies indicate reductions of 50-70% in serum DHT and 60-70% in scalp tissue DHT depending on dosage.
By lowering DHT availability, finasteride can interrupt the miniaturisation process and, in responsive individuals, allow follicles to return to a thicker growth cycle. However, the drug does not work for everyone, and results typically require several months of consistent use to become apparent.
Clinical Evidence & References
Clinical trials support finasteride's efficacy in slowing or reversing male pattern hair loss. A phase III randomised controlled trial involving 458 men demonstrated that topical finasteride spray (and by extension, oral formulations) produced measurable improvements in hair count and slowing of further loss compared to placebo. Studies confirm significant reductions in both serum and scalp DHT concentrations, with effects proportional to dosage.
However, efficacy varies between individuals. Not all men experience regrowth, and some experience only stabilisation of existing hair. Finasteride is less well-studied in women with androgenetic alopecia, and evidence for its use in female pattern hair loss remains more limited. Results typically require 3-6 months to become evident, and effects may plateau or reverse if treatment is discontinued.
Published Research
How to Use
Finasteride is a prescription medication and must be obtained through a healthcare provider. The typical prescribed dose for male pattern hair loss is 1 mg taken orally once daily. Consistency is essential; benefits require ongoing treatment, as hair loss can resume when the medication is stopped. Results should be assessed over a minimum of 3-6 months before determining effectiveness. Women of childbearing age should not handle finasteride tablets and should not become pregnant whilst taking the medication due to potential effects on male foetal development.
If you’re pregnant or breastfeeding, please check with us first — hello@skintique.co.uk.
Safety & Precautions
If you’re pregnant or breastfeeding, please check with us first — hello@skintique.co.uk.
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