Hair Loss Medications: Finasteride, Minoxidil, and Beyond
A comprehensive overview of FDA-approved and commonly prescribed hair loss medications, including how they work, side effects, and who they're right for.
The Two FDA-Approved Options
After decades of research, only two medications have full FDA approval for treating pattern hair loss: minoxidil (topical) and finasteride (oral). Everything else is either off-label, supplemental, or experimental. Understanding how these two drugs work is the foundation of medical hair loss treatment.
Minoxidil (Rogaine)
Originally developed as an oral blood pressure medication, minoxidil's hair growth effects were discovered as a side effect. The topical version is available over the counter in 2% and 5% formulations (liquid and foam). It works by shortening the resting phase of the hair cycle and extending the growth phase. It also increases blood flow to follicles.
Results take 3-6 months of consistent daily use. About 40-60% of users see meaningful improvement. If you stop using it, any gained hair is lost within 3-6 months. Common side effects include scalp irritation and unwanted facial hair growth (more common in women). Oral minoxidil at low doses (2.5-5mg) is increasingly prescribed off-label by dermatologists for patients who find topical application inconvenient.
Finasteride (Propecia)
A prescription medication that blocks the enzyme 5-alpha reductase, which converts testosterone to DHT (dihydrotestosterone). DHT is the hormone primarily responsible for miniaturizing hair follicles in androgenetic alopecia. Finasteride reduces scalp DHT levels by about 60-70% at the standard 1mg dose.
Clinical trials showed 83% of men maintained their hair count after 2 years, and 66% showed measurable regrowth. It's most effective at maintaining existing hair rather than regrowing lost hair. Side effects can include decreased libido and erectile changes in a small percentage of users (reported in 1-2% of clinical trial participants, with most resolving after stopping the medication).
Dutasteride (Off-Label)
A more potent 5-alpha reductase inhibitor that blocks both type I and type II enzymes (finasteride blocks only type II). Reduces DHT levels by about 90%. Approved for prostate enlargement but prescribed off-label for hair loss in some countries. Studies suggest it's more effective than finasteride for hair growth, but it also has a higher side effect profile and a much longer half-life (5 weeks vs. 6-8 hours).
Spironolactone (Women Only)
Anti-androgen medication prescribed off-label for female pattern hair loss. Blocks androgen receptors and reduces androgen production. Not appropriate for men due to feminizing side effects. Commonly prescribed at 100-200mg daily. Takes 6-12 months to see results. Must not be used during pregnancy.
Topical Finasteride
A newer option gaining traction - finasteride compounded into a topical solution applied to the scalp. The idea is to deliver DHT-blocking effects locally while minimizing systemic absorption and potential side effects. Several studies suggest topical finasteride can reduce scalp DHT comparably to oral finasteride with lower serum DHT suppression. Available through compounding pharmacies and some telehealth platforms.
Building a Protocol
Most dermatologists recommend a combination approach. A common starting protocol for men: finasteride 1mg daily plus minoxidil 5% once or twice daily. For women: minoxidil 2% or 5% daily, with spironolactone added if the response is insufficient. PRP, LLLT, and supplements can be layered on top. Consistency is everything - these medications only work while you use them.