Finasteride, a potent five alpha reductase inhibitor, was originally developed to treat prostate enlargement linked to elevated DHT levels. While topical forms aim to target hair follicles directly, they can still enter systemic circulation, complicating dosage and potential side effects. Effective dosages for hair growth vary dramatically, ranging from as low as 0.1 mg to as high as 5 mg per day, highlighting the need for careful consideration in treatment choices.
