A comprehensive review of FDA-approved pharmacological treatments — from first-line topical agents to the latest JAK inhibitors — backed by clinical trial evidence.
Hair loss affects more than 80 million people in the United States alone. For most patients, surgery is unnecessary — modern pharmacology offers proven, accessible options that halt progression and stimulate meaningful regrowth.
Androgenetic alopecia (AGA), or pattern hair loss, is the most prevalent form. It is driven by dihydrotestosterone (DHT), a potent androgen derived from testosterone that progressively miniaturises genetically susceptible hair follicles. A separate condition, alopecia areata (AA), occurs when the immune system attacks follicles directly — an autoimmune mechanism requiring a completely different therapeutic approach.
The treatment landscape has evolved dramatically. Two drug classes have historically served as first-line therapies — minoxidil and finasteride. A third class, the JAK inhibitors, has recently transformed outcomes for autoimmune-driven hair loss, representing the first systemic approvals specifically for alopecia areata.
Originally developed as an antihypertensive agent, minoxidil is a potassium channel opener. Applied to the scalp, it dilates blood vessels and increases blood flow to follicles, extending the anagen (growth) phase while shortening telogen. The precise hair-specific mechanism involves upregulation of prostaglandin E2 and direct mitogenic stimulation of follicular cells. Available as a 2% solution (women), 5% solution or foam (men and women), and as low-dose oral tablets.
Dutasteride inhibits both type I and type II 5-alpha-reductase isoenzymes, unlike finasteride which targets only type II. This broader inhibition produces a far greater reduction in serum and scalp DHT — approximately 90–95% vs finasteride's 70%. Head-to-head trials confirm dutasteride produces significantly higher hair count gains. While not FDA-approved for AGA in the US, it is widely prescribed off-label for patients who respond inadequately to finasteride.
- 1.Gupta AK et al. Meta-analysis of minoxidil efficacy in androgenetic alopecia (23 RCTs).JAMA Dermatology,2022.
- 2.Leyden J et al. Ten-year finasteride outcomes study.Journal of the American Academy of Dermatology,2021.
- 3.King B et al. BRAVE-AA1 & BRAVE-AA2 Phase 3 trials — baricitinib in severe alopecia areata.NEJM,2022.
- 4.Practical Dermatology. Baricitinib, ritlecitinib, deuruxolitinib Phase 3 summary. March 2026.
- 5.Masterclasses in Dermatology. Evidence-based hair growth and hair loss treatment review, 2024–2025.
- 6.Frontiers in Pharmacology. Comparative efficacy and safety of JAK inhibitors in alopecia areata: systematic review and network meta-analysis. 2024.
- 7.Annals of Dermatology. Updates in treatment for androgenetic alopecia. December 2025.
- 8.National Alopecia Areata Foundation (NAAF). FDA-approved JAK inhibitors guide. 2026.
- 9.Chen M et al. Low-dose oral minoxidil and blood pressure: systematic review and meta-analysis.JAAD,2025.
- 10.Babul N et al. Comparative efficacy of JAK inhibitors for severe AA: Bayesian network meta-analysis.Journal of Dermatology,2025.
This article is for educational purposes only and does not constitute medical advice. Hair loss treatment decisions should always be made in consultation with a licensed dermatologist or trichologist. Always read the full prescribing information for any medication.