Hair antiandrogens compared
A comparison of the main antiandrogens used to treat hair loss, with their doses, populations, adverse effects and level of evidence. Informative content; it does not replace individualised medical assessment.
| Molecule | FinasterideView sheet | DutasterideView sheet | SpironolactoneView sheet | BicalutamideView sheet |
|---|---|---|---|---|
| Pharmacological class | 5-alpha-reductase inhibitor (type II) | 5-alpha-reductase inhibitor (types I and II) | Aldosterone antagonist with antiandrogen effect | Non-steroidal antiandrogen |
| Main mechanism | Reduces DHT by blocking type II 5-AR | Reduces DHT by over 90% (dual blockade, types I and II) | Blocks the androgen receptor and lowers androgen production | Selective androgen-receptor blockade |
| Route of administration | Oral (also topical) | Oral | Oral | Oral |
| Typical hair dose | 1 mg/day | 0.5 mg/day (off-label) | 50-200 mg/day | 25-50 mg/day |
| Main population | Men (off-label in postmenopausal women) | Men (off-label) | Women (not in men) | Women (not in men) |
| Key adverse effects | Sexual (uncommon, reversible), gynaecomastia | Similar to finasteride; very long half-life | Hyperkalaemia, menstrual changes, breast tenderness | Hepatotoxicity, breast tenderness |
| Recommended monitoring | Consider PSA (reduces it ~50%) | PSA; do not donate blood | Potassium and blood pressure | Liver function (transaminases) |
| Pregnancy | Contraindicated (teratogen) | Contraindicated (teratogen) | Contraindicated (feminisation of male foetus) | Contraindicated |
| Level of evidence (hair) | High | Moderate-high | Moderate | Limited |
When used for hair purposes, all these drugs are often used off-label and require medical prescription and follow-up. Doses are indicative and should always be adjusted to clinical judgement.