Short answer: Topical minoxidil (Rogaine) is sold over the counter to regrow hair. Ketoconazole shampoo is labeled for dandruff (1%, Nizoral) or a fungal skin rash (2%), not hair loss.123 One small 1998 study found 2% ketoconazole shampoo improved hair density about as much as 2% minoxidil; its authors called for a larger trial.4
| Ketoconazole shampoo | Topical minoxidil (Rogaine) | |
|---|---|---|
| Label use | 1% (OTC): flaking, scaling and itching from dandruff. 2% (prescription): tinea versicolor23 | Regrow hair on the top of the scalp15 |
| Approved for hair loss | No23 | Yes, over the counter1 |
| Label directions | 1%: lather, rinse, repeat, every 3 to 4 days for up to 8 weeks, then as needed2 | Men's foam: half a capful twice a day. Women's 2% solution: 1 mL twice a day15 |
| When to judge it | Dandruff: ask a doctor if no better in 2 to 4 weeks2 | Stop and ask a doctor if no regrowth in 4 months1 |
| Reaches the blood? | 2%: not detected in plasma after months of shampooing3 | Not stated on the Drug Facts label |
| Stop and ask a doctor if | A rash appears2 | Chest pain, fast heartbeat, faintness or dizziness; scalp irritation; unwanted facial hair1 |
| Hair study | 2% shampoo: hair density, size and growing-phase share improved4 | 2% minoxidil: improved almost similarly4 |
Only in a small 1998 study. It compared 2% ketoconazole shampoo with a plain shampoo used with or without 2% minoxidil in androgenic alopecia. Hair density, hair size and the share of hairs in the growing phase improved almost similarly with ketoconazole and with minoxidil, and ketoconazole seemed to lower scalp oil. The authors said the clinical meaning awaits a larger controlled study.4 The abstract gives no group sizes or numbers.
Rogaine is an over-the-counter hair regrowth product. The men's label says results may show at 2 months with twice-daily use, some men need at least 4 months, using more or more often will not help, and hair loss returns if you stop.1
Nizoral 1% is an anti-dandruff shampoo for adults and children 12 and older.2 The 2% shampoo is a prescription product for tinea versicolor; in 11 trials for dandruff or seborrheic dermatitis, more hair shedding and irritation occurred in under 1% of patients.3 Ketoconazole tablets are a different product with serious liver warnings and are not covered here.
More detail: Oral vs topical minoxidil: what is the difference for hair loss?, and the Ketoconazole and Topical Minoxidil guides.