| How it works | Vasodilator , extends the anagen (growth) phase. Mechanism still not fully understood. | Blocks 5-Ξ±-reductase type II, lowering scalp DHT by ~70%. | Blocks 5-Ξ±-reductase types I + II, lowering scalp DHT by ~90%. | Concentrated platelets injected into the scalp , growth factors stimulate dormant follicles. |
| Evidence quality | Strong , multiple RCTs, FDA-approved since 1988. | Strong , gold-standard 5-year Propecia trial showed regrowth in 65%. | Strong , superior to finasteride in head-to-head (Olsen 2006). | Moderate , meta-analyses show modest density gain; protocols vary wildly. |
| How long until you see results | 4 to 6 months (initial shed at 4 to 8 weeks is normal). | 3 to 6 months for stop, 6 to 12 for regrowth. | Similar to finasteride, slightly faster onset. | After the third session (~3 months). |
| Typical UK cost / month | Β£10 to Β£25 | Β£10 to Β£20 (generic) | Β£25 to Β£60 (off-label for hair loss) | Β£200 to Β£500 per session, 3 to 4 sessions needed up front |
| Side effect risk | Low , scalp irritation, occasional shedding, rare facial hair growth. | Low to moderate , ~2% report libido/erectile issues; usually reversible. | Moderate , same profile as finasteride, slightly higher rates. | Very low , bruising, transient soreness; no systemic effects. |
| Works for women? | Yes , 2% solution / 5% foam approved for female pattern loss. | Not approved; off-label use post-menopause only. | Not approved; teratogenic , must avoid in women of childbearing age. | Yes , works for diffuse female pattern thinning. |
| Stops loss vs regrows | Both, but regrowth modest (~10 to 15% density gain). | Primarily stops loss; ~65% see some regrowth. | Both, with stronger regrowth than finasteride. | Primarily densifies existing hair; minimal new growth. |
| Lifetime commitment? | Yes , gains reverse within 3 to 6 months of stopping. | Yes , DHT rebounds within weeks. | Yes , same as finasteride. | Maintenance sessions every 6 to 12 months indefinitely. |
| Best for | Anyone starting out, or as part of a combo stack. | Men 18 to 50 with active pattern loss who want a single oral. | Men who plateau on finasteride and want stronger DHT suppression. | Anyone who wants a drug-free option or to complement medical therapy. |