Finasteride works — for about 80–85% of men — but only if you take it correctly and give it enough time. Here's the practical playbook: dose, timing, food, the "dread shed," side effects, and when to adjust.
Finasteride for male pattern hair loss is 1 mg once daily, per the FDA DailyMed Propecia prescribing information. That's the FDA-approved dose that was studied in the original trials and remains the standard of care per the American Academy of Dermatology's men's hair loss guidance.
Pharmacokinetic data has shown that even 0.25 mg daily suppresses scalp DHT substantially — about 60–70% of the effect of 1 mg — and some clinicians and patients prefer a lower dose (0.25 mg or 0.5 mg daily) to reduce side effect risk while keeping most of the benefit. A JAAD review of evidence-based finasteride dosing supports this for men who want a lower systemic exposure. Topical finasteride (compounded) is another option with even lower systemic absorption.
Finasteride has a short blood half-life (5–6 hours), but its biological effect on DHT is much longer — one dose lasts roughly 24 hours. That means once-daily dosing is enough. The most important thing is consistency: pick a time of day and stick to it. Morning with coffee, evening before bed, after brushing teeth — any of these works. The worst option is "whenever I remember," because that means frequent missed doses.
Doesn't matter. StatPearls' finasteride pharmacology review notes that food has no clinically meaningful effect on absorption. Take it whichever way fits your routine.
Take it as soon as you remember, unless it's close to your next dose. In that case, skip the missed dose and take the next one at the regular time. Do not double up to "catch up." Missing a dose here and there over months won't erase your progress — but daily consistency matters for the best outcome.
Many men experience increased shedding in the first 1–3 months. This is called the "dread shed" in hair-loss communities, and it's a sign the drug is working: weak, miniaturized hairs are being pushed out so new, thicker hairs can grow in their place. It's not a reason to stop. If you quit now, you'll have panicked at the exact moment the drug started working.
Shedding slows. Most men find that hair loss has stopped or dramatically slowed by month 6. You won't see meaningful regrowth yet — stabilization is the main win here. If you're still losing hair aggressively at month 6, talk to your prescriber about adding minoxidil or reassessing dose.
Visible regrowth starts to appear for the ~80–85% of men who respond. Thickening at the crown is usually noticeable before frontal/temple regrowth. Keep taking photos from the same angle every month — subtle gains are easy to miss in the mirror.
Finasteride's full effect is visible by the one- to two-year mark. After that, the medication maintains your progress — think of it as ongoing maintenance. Long-term studies of finasteride 1 mg show most men who respond continue to hold or modestly improve their result as long as they stay on the drug.
No direct interaction. Drink normally if you drink.
No meaningful interactions. Saw palmetto (an OTC supplement sometimes taken for hair loss) is thought to inhibit 5-alpha-reductase like finasteride; combining doesn't obviously help and muddles side-effect attribution. Stick with the prescription drug alone.
Finasteride has remarkably few drug interactions. It's metabolized via CYP3A4 but in most cases doesn't require dose changes even when combined with other CYP3A4 drugs. If you're on strong CYP3A4 inhibitors (ketoconazole, ritonavir) long-term, tell your prescriber — usually no change is needed.
Finasteride is not prescribed to women. It's teratogenic — can cause severe genital birth defects in a male fetus. Women who are or may become pregnant should not take it, and should not handle crushed or broken tablets. Whole, coated tablets are safe to touch. Postmenopausal women and women with PCOS-related hair loss are sometimes treated with spironolactone or topical minoxidil instead — that's a different conversation with a dermatologist.
Safe to continue for the vast majority of men. Finasteride reduces ejaculate volume slightly but does not meaningfully impair fertility for most men. Data show no harm to a fetus through semen. If fertility issues arise and you want to rule out any contribution, stopping for 3 months fully clears the drug.
Finasteride lowers PSA levels by roughly 50%. If you have a family history of prostate cancer or are being monitored with PSA, tell your prescriber before starting — they need to know to multiply your PSA by 2 to interpret it correctly. Finasteride does not cause prostate cancer; the PCPT trial actually showed a lower overall rate of prostate cancer in men on finasteride, with some nuance about higher-grade tumors that has been extensively reanalyzed since.
In the original Propecia trials at 1 mg daily, side effect rates were:
Most men have no side effects. If you experience any, most resolve within weeks to months of stopping. A controversial condition called post-finasteride syndrome — persistent sexual or mood symptoms after stopping — has been reported in a small number of men, though the causal link and mechanism remain debated in the medical literature (see JAMA Dermatology's evidence review).
Report side effects to your prescriber. Options include lowering the dose (1 mg → 0.5 mg or 0.25 mg), switching to topical finasteride, or stopping and reassessing.
If you stop taking finasteride, the gains reverse. DHT levels return to baseline within weeks, and within 6–12 months most of the hair you regrew will be lost again. There's no "finishing" finasteride — it's maintenance. You can restart any time.
Reasons to stop: intolerable side effects, personal choice, or a change in treatment plan (e.g., switching to dutasteride for non-response).
Some men do, and it partially works — DHT suppression is lower on an every-other-day schedule than daily, but there's still meaningful effect. If cost or side effects are the reason, a lower daily dose (0.25 mg) usually beats every-other-day dosing for consistency.
Sometimes. Finasteride is best at maintaining and regrowing the crown and mid-scalp. Frontal/temple regions are generally more resistant to regrowth. Starting treatment earlier — while you still have hair in the hairline — produces better results.
Generic finasteride 1 mg is typically $4–$15 for a 30-day supply using Mark Cuban Cost Plus Drugs, GoodRx, or Walmart's generic program. A 90-day supply is often under $25. Brand Propecia is significantly more expensive — unnecessary since the generic is fully equivalent (see our generic vs brand guide).
Yes, and most clinicians recommend it. The two drugs work by different mechanisms and the combination gives better regrowth than either alone. Minoxidil is available OTC (topical) or by prescription (oral).