Propecia (Finasteride)
Symptoms, Causes & Treatment
Propecia (finasteride 1mg) is the most clinically effective oral treatment for male androgenetic alopecia, slowing hair loss in 80–90% of men and producing visible regrowth in the majority within 12 months. It requires lifelong use to maintain its benefits.
What is Propecia (Finasteride)?
Finasteride inhibits 5-alpha reductase type 2, the enzyme that converts testosterone to dihydrotestosterone (DHT) in hair follicles. Elevated DHT causes follicular miniaturisation and progressive hair loss in genetically susceptible men. Reducing DHT by 70% with finasteride 1mg daily halts this process and restores hair density in most treated men. It is not licensed for use in women of childbearing potential due to teratogenicity risk.
Symptoms of Androgenetic Alopecia
Androgenetic alopecia follows characteristic patterns: Hamilton-Norwood in men; Ludwig in women. Pattern and severity guide treatment choice and prognosis.
Gradual recession at temples and frontal hairline · Thinning at the crown and vertex · Hamilton-Norwood pattern of male pattern hair loss · Hair loss in a Ludwig pattern in women (frontal preservation with crown thinning) · Associated greasy scalp
Breast tenderness or nipple discharge on finasteride (rare but seek review) · Significant ongoing sexual side effects (ejaculatory dysfunction, reduced libido) · Depressive symptoms while on finasteride — discuss with prescribing doctor
Breast tenderness or discharge on finasteride · Persistent sexual dysfunction · Depressive symptoms developing on finasteride — report these side effects to your doctor promptly.
Why Use Propecia (Finasteride)?
Androgenetic alopecia is caused by DHT-mediated follicle miniaturisation in genetically susceptible individuals. Finasteride directly targets this mechanism.
Finasteride (Propecia) is a 5-alpha reductase inhibitor that reduces DHT by 70%, slowing or reversing androgenetic alopecia. It is taken as 1mg daily. Response takes 3–6 months. It must be continued long-term — hair loss resumes within 12 months of stopping.
Finasteride side effects occur in 1–2% of users: reduced libido, erectile dysfunction, ejaculatory dysfunction, and breast tenderness. Post-finasteride syndrome (persistent sexual side effects after stopping) is recognised but rare. Depression has been reported.
Minoxidil is a topical vasodilator used for androgenetic alopecia in both men and women. Available as 2% or 5% solution or foam, applied twice daily. It prolongs the anagen growth phase. Oral low-dose minoxidil (0.625–2.5mg) is increasingly used off-label.
Hair transplantation (follicular unit extraction or transplantation) is the only permanent surgical solution for androgenetic alopecia. It redistributes DHT-resistant occipital follicles to the balding area. Medical treatment must be continued alongside transplant to preserve existing hair.
Finasteride must not be prescribed to women of childbearing potential as it causes fetal genitourinary abnormalities. It is contraindicated in pregnancy. Women with androgenetic alopecia are treated with minoxidil, anti-androgens (spironolactone), or HRT where appropriate.
Finasteride has been associated with a small reduction in prostate cancer risk in clinical trials. It is used at 5mg (Proscar) for benign prostatic hyperplasia. Men on finasteride for BPH should have PSA measured and the value doubled to correct for medication effect.
Key Risk Factors
Diagnosing & Monitoring Androgenetic Alopecia
Androgenetic alopecia is a clinical diagnosis. Blood tests exclude reversible causes and provide baseline monitoring parameters. PSA must be recorded before finasteride and the value doubled on treatment.
Treatment for Androgenetic Alopecia (Propecia)
Finasteride is the cornerstone oral treatment. Minoxidil is the main topical adjunct. Surgical transplantation is the permanent solution for established pattern loss.
Supportive Measures
Combine finasteride with minoxidil 5% twice daily for best results. Use a gentle shampoo. Avoid anabolic steroids. Protect the scalp from UV with SPF 30+. Take finasteride at the same time each day. Allow 12 months before assessing full treatment response.
Long-Term Androgenetic Alopecia Management
Androgenetic alopecia is a lifelong condition requiring continuous treatment. Combination of finasteride and minoxidil provides the best long-term outcome. Annual review assesses treatment response, side effects, and PSA. Hair transplantation provides permanent results but medical treatment must continue.
When to Seek Help
Breast tenderness or nipple discharge on finasteride · Significant depressive symptoms developing on finasteride · Severe sexual dysfunction — discuss with your prescribing doctor and consider stopping.
See a GP or hair loss specialist if you are concerned about progressive hair loss. Finasteride and minoxidil are most effective when started early. An online GP consultation is a convenient first step for androgenetic alopecia assessment.
Getting the Best from Finasteride
Maximising the benefit of finasteride requires early treatment, combination with minoxidil, and lifelong adherence.
Start finasteride early in hair loss progression. It is most effective at preventing further loss than regrowing already miniaturised follicles. Starting at Hamilton-Norwood grade I–II gives the best long-term outcome.
Use finasteride and minoxidil together for best results. Clinical trials show combination therapy produces 30–40% greater hair density improvement than either agent alone. Both must be continued long-term.
Continue finasteride long-term. Hair loss resumes within 9–12 months of stopping. Assess response after 12 months of treatment — if effective, continue indefinitely to maintain results.
Use SPF 30+ sunscreen on exposed scalp areas. UV radiation accelerates androgenetic alopecia by damaging follicular stem cells. Wearing a hat in strong sunlight also reduces UV damage to thinning areas.
Have annual blood tests if taking finasteride for hair loss: PSA (multiplied by 2 to correct for finasteride effect), liver function, and haematology. Report any sexual side effects promptly — stopping the drug reverses effects in most cases.
Avoid anabolic steroids, which dramatically accelerate androgenetic alopecia by raising DHT levels. Testosterone supplementation and some bodybuilding supplements also accelerate hair loss in genetically susceptible individuals.
Getting Finasteride (Propecia)
Finasteride is a prescription-only medication available from a GP, private hair loss clinic, or online pharmacy. Baseline blood tests (PSA in men over 50, LFTs) are recommended before starting. Annual monitoring and side effect review is important.
Expert clinical advice, when you need it.
Propecia (Finasteride) — Frequently Asked Questions
Finasteride (Propecia) blocks the enzyme 5-alpha reductase type 2, reducing conversion of testosterone to dihydrotestosterone (DHT). This reduces DHT by 70%, slowing follicle miniaturisation and restoring hair density in 80–90% of men within 12 months.
Stabilisation of hair loss is seen within 3–6 months. Visible regrowth typically appears at 6–12 months and full benefit at 24 months. Finasteride must be continued indefinitely — hair loss resumes within 9–12 months of stopping.
Sexual side effects (reduced libido, erectile dysfunction, ejaculatory dysfunction) occur in 1–2% of users and are usually reversible on stopping. Post-finasteride syndrome (persistent effects after stopping) is rare but recognised. Depression has also been reported. Discuss any side effects with your prescribing doctor.
Yes. Finasteride and minoxidil work through complementary mechanisms. Combination therapy produces significantly better hair density outcomes than either agent alone in clinical trials. Both must be continued long-term to maintain the benefit.
Finasteride is not used in women of childbearing potential due to teratogenicity risk in male fetuses. Women with androgenetic alopecia are treated with minoxidil, spironolactone, or HRT. Dutasteride is occasionally used off-label in post-menopausal women under specialist supervision.
Finasteride halves PSA levels. If monitoring PSA while taking finasteride, multiply the result by 2 to estimate the true PSA. This correction is essential to avoid missing early prostate cancer. Always inform your GP and urologist that you are taking finasteride when PSA is discussed.
Hair transplantation (follicular unit extraction or transplantation) permanently redistributes DHT-resistant follicles from the occiput to balding areas. Medical treatment (finasteride and minoxidil) must be continued alongside transplant to protect remaining native hair from ongoing androgenetic alopecia.
A GP can prescribe finasteride and topical minoxidil, arrange baseline blood tests (PSA, LFTs), and monitor for side effects. Hair loss clinics and dermatologists provide specialist assessment and advanced treatments including oral minoxidil, PRP, and referral for hair transplantation.