Finasteride is a prescription-only medication used to treat male pattern baldness (androgenetic alopecia) in men. Originally developed at a 5 mg dose for benign prostatic hyperplasia (BPH), a lower dose of 1 mg daily was later approved specifically for hair loss under the brand name Propecia.
In the UK, finasteride 1 mg is licensed by the Medicines and Healthcare products Regulatory Agency (MHRA) for treating hair loss in men aged 18 to 41, though it is commonly prescribed off-label to older men as well.
How Does Finasteride Work?
Finasteride works by inhibiting the enzyme 5-alpha reductase type II, which converts testosterone into dihydrotestosterone (DHT). DHT is the primary androgen responsible for shrinking hair follicles in genetically susceptible men, a process known as follicular miniaturisation.
By reducing DHT levels by approximately 60–70% in the bloodstream, finasteride slows or halts further hair loss in most men and can promote partial regrowth in many cases.
Who Can Take Finasteride?
- Men aged 18 and over experiencing male pattern hair loss
- It is not suitable for women or children
- Women who are pregnant or may become pregnant must not handle crushed or broken tablets due to the risk of birth defects
- Men with liver disease should discuss suitability with their prescriber
What Results Can You Expect?
Finasteride is a long-term treatment. Most men need to take it for at least 3 to 6 months before noticing a visible reduction in hair loss, and up to 12 months for meaningful regrowth. Clinical trials show that after two years, approximately 83% of men maintained or increased their hair count compared to baseline.
Finasteride is most effective when started early in the hair loss process. If you stop taking it, any hair you have regained is likely to be lost within 6 to 12 months.
How to Get Finasteride in the UK
Finasteride requires a prescription in the UK. You can obtain it through your GP, a private clinic, or a GPhC-registered online pharmacy. Generic finasteride is significantly cheaper than branded Propecia, typically costing between £5 and £15 per month from UK pharmacies.