Overview
Pharmacological treatments for hair loss primarily target the hormonal pathways involved in miniaturization or mechanisms that stimulate the anagen phase of the hair cycle. Efficacy and safety profiles are well-established for regulatory-approved drugs, while off-label treatments carry different levels of evidence.
Minoxidil
Mechanism: A potassium channel opener that causes hyperpolarization of cell membranes, leading to vasodilation and increased blood flow to follicles. It is thought to prolong the anagen phase and increase follicle size [1].
Usage: Topical solution or foam (2% - 5%). Oral minoxidil (off-label) is increasingly prescribed but carries a higher risk of systemic side effects.
Finasteride
Mechanism: A type II 5-alpha-reductase inhibitor that reduces the conversion of testosterone to dihydrotestosterone (DHT) [2]. Lowering scalp DHT levels can arrest follicular miniaturization.
Usage: Oral tablet (1mg daily). Topical formulations are studied to reduce systemic exposure.
Dutasteride
Mechanism: Inhibits both Type I and Type II 5-alpha-reductase isoenzymes. It is more potent than finasteride in reducing serum DHT but has a longer half-life.
Status: Approved for hair loss in some countries (e.g., South Korea, Japan) but off-label in the US/EU.
Safety Considerations
All medications carry potential risks. Finasteride is associated with sexual side effects in a small percentage of users. Minoxidil may cause hypertrichosis (unwanted hair growth) or cardiovascular changes. Consultation with a specialist is mandatory.