Finasteride for Hair Loss: The Complete Guide (2026)
Oral finasteride is the most-studied prescription hair-loss treatment, with three decades of randomised trial data, a well-characterised effect size, and a side-effect profile that is real but smaller and rarer than internet anecdote suggests. Here is the decision-first guide — efficacy, dosing, side effects, who should and shouldn't take it, and how to start.