Hair-loss treatments, compared
What actually works for hereditary hair loss, told straight: the two treatments the FDA has approved, the two used off-label, how well each works, the side effect that decides it, and our independent recall-safety rating. We rate medications; we don’t sell them or prescribe them.
The one thing to get straight first
Only two hair-loss treatments are FDA-approved: topical minoxidil (Rogaine, over the counter, men and women) and oral finasteride (Propecia, prescription, men). Dutasteride and spironolactone are used off-label — real options a prescriber may choose, but not approved hair-loss drugs. And all of them work only while you keep using them.
FDA-approved for hair loss
Minoxidil (Rogaine)
Men & women · Topical · Over the counter
- Approved for
- FDA-approved (over the counter) for hereditary hair loss — the 5% foam/solution for men, and 2% and 5% for women. It is the only topical hair-loss treatment sold without a prescription.
- How it works
- Applied to the scalp. It is thought to prolong the growth phase of the hair follicle and enlarge miniaturised follicles; the exact mechanism for hair growth is not fully established.
- How well
- Regrows or thickens hair in a portion of users over about 4 months of twice-daily use; results are best on the crown, and the benefit only lasts while you keep using it — stop, and regrown hair is shed within months.
The trade-off
Expect an early, temporary increase in shedding in the first weeks as follicles reset — it is not the drug failing. Scalp irritation is common. The label's own limits matter here: do not use it under 18, on a scalp that is red, inflamed, infected or painful, or when hair loss is SUDDEN, PATCHY or of unknown cause — that pattern needs a diagnosis, not minoxidil. Ask a doctor first if you have heart disease, and stop and seek care for chest pain, a racing heartbeat, dizziness or fainting, sudden unexplained weight gain, or swollen hands or feet. Oral minoxidil for hair loss is a separate, off-label use, and the approved oral form carries an FDA BOXED WARNING — FDA's highest tier — for fluid around the heart (pericardial effusion) that can progress to tamponade, and for worsening angina; at blood-pressure doses the label requires a beta-blocker and a diuretic alongside it. Hair-loss doses are far lower, which is why it is prescriber-supervised (the pills are FDA-approved for blood pressure), taken only under a prescriber.
Finasteride (Propecia)
Men · Oral pill · Prescription
- Approved for
- FDA-approved (1 mg, as Propecia) for male pattern hair loss on the vertex and mid-scalp. It is NOT approved — and is contraindicated — for women of childbearing potential.
- How it works
- A once-daily pill that blocks 5-alpha-reductase type II, the enzyme that converts testosterone to DHT, the hormone that drives male pattern hair loss. Lowering scalp DHT slows the miniaturisation of follicles.
- How well
- In the trials most men saw hair loss stop, and a majority had some regrowth over 1-2 years; as with minoxidil, the benefit reverses within about a year of stopping.
The trade-off
A minority of men report sexual side effects — reduced libido, erectile or ejaculation problems — which usually resolve on stopping, though some report persistence (the debated 'post-finasteride syndrome'). The label also records depression and suicidal ideation, and male breast cancer, as postmarketing reports — tell a prescriber about any mood change or breast lump or tenderness. It notes too that 5-alpha-reductase inhibitors may raise the risk of high-grade prostate cancer, which is the other half of the PSA point. Because it lowers DHT, it can lower PSA (a prostate-cancer screening value). Pregnant women must not handle crushed or broken tablets — finasteride can harm a male foetus.
Used off-label for hair loss
Real options a prescriber may reach for, but not FDA-approved for hair — the distinction matters.
Dutasteride
Men · Oral pill · Prescription
- Approved for
- In the US, dutasteride is FDA-approved for an enlarged prostate (BPH), NOT for hair loss — using it for hair is off-label (it is approved for hair loss in some other countries, e.g. South Korea).
- How it works
- A once-daily pill that blocks both type I and type II 5-alpha-reductase, so it lowers DHT more completely than finasteride, which blocks only type II.
- How well
- Off-label evidence and overseas approvals suggest it can be at least as effective as finasteride for male pattern hair loss, but it is not FDA-approved for this use, so it is a prescriber's off-label judgement.
The trade-off
Similar sexual side effects to finasteride, and a much longer half-life, so effects and its effect on PSA and on a male foetus persist longer after stopping. It is CONTRAINDICATED in women who are or may become pregnant. And the handling risk is broader than finasteride's, not the same: finasteride tablets are coated, so intact tablets are safe to handle, whereas dutasteride is a capsule and the label states the drug can be absorbed through the skin from a leaking one — so pregnant or potentially pregnant women should not handle the capsules at all. Do not donate blood until at least 6 months after the last dose. Off-label — discuss the trade-off with a prescriber.
Spironolactone
Women · Oral pill · Prescription
- Approved for
- FDA-approved as a diuretic and for conditions like high blood pressure and heart failure — NOT for hair loss. It is used off-label for female pattern hair loss because it is an anti-androgen; it is not used for male pattern hair loss (it can feminise).
- How it works
- A once-daily pill that blocks androgen receptors and reduces androgen production, countering the hormonal driver of hair thinning in some women.
- How well
- Off-label evidence suggests it can slow female pattern hair loss and modestly improve density in some women, often combined with topical minoxidil; it is not FDA-approved for this, so it is an off-label choice.
The trade-off
It is CONTRAINDICATED if you already have high potassium, Addison's disease, or take eplerenone. It raises potassium further (avoid potassium supplements and salt substitutes without monitoring, and note that ACE inhibitors, ARBs, NSAIDs and trimethoprim all push it higher), and must not be used in pregnancy — it can affect the development of a male foetus. Off-label; a prescriber decision, usually after other options.
Frequently asked questions
What is the most effective hair-loss treatment?
There is no single winner, and the honest answer depends on who you are. For men, the two FDA-approved options — topical minoxidil and oral finasteride — are often used together and work better combined than alone. For women, topical minoxidil is the FDA-approved option, sometimes paired with off-label spironolactone. Every one of them only works while you keep using it, and the right choice depends on your sex, your health and which side effects you can accept — a prescriber's call.
Which hair-loss treatments are actually FDA-approved?
Only two: topical minoxidil (Rogaine, over the counter, for men and women) and oral finasteride (Propecia, prescription, for men). Dutasteride and spironolactone are used off-label for hair loss in the US — dutasteride is FDA-approved for an enlarged prostate, spironolactone as a diuretic — so they are a prescriber's off-label judgement, not approved hair-loss drugs.
Do you have to keep using hair-loss treatment forever?
Essentially, yes. Minoxidil and finasteride treat an ongoing process; they do not cure it. When you stop, the hair they preserved or regrew is usually lost within about 6-12 months, and hair loss resumes where it would have been. That is worth knowing before you start.
Does finasteride cause permanent side effects?
Most men have no sexual side effects, and in those who do, they usually resolve after stopping. A minority report symptoms that persist — the debated 'post-finasteride syndrome' — which is why the decision is an individual one to make with a prescriber. Finasteride also lowers PSA (a prostate-screening blood test) and must not be handled by pregnant women.
Sources: each drug’s FDA label (openFDA / DailyMed), linked on its card. This is general reference information, not medical advice, and not a recommendation to take any drug — hair-loss treatment, and especially the off-label options, is a decision to make with a prescriber.