Dutasteride is a medication primarily used to treat benign prostatic hyperplasia (BPH), and it is also used off-label for androgenetic alopecia, commonly known as male pattern hair loss. It works by inhibiting the activity of both Type I and Type II 5-alpha-reductase enzymes, which are responsible for converting testosterone into dihydrotestosterone (DHT).

DHT plays a significant role in androgenetic alopecia by contributing to the gradual miniaturization of hair follicles. Over time, affected follicles produce thinner, shorter hairs, leading to visible hair thinning and a receding hairline. By reducing DHT levels, dutasteride may help slow hair loss and support hair retention in suitable patients.

Compared with finasteride, which primarily inhibits Type II 5-alpha-reductase, dutasteride inhibits both enzyme types and can produce a greater reduction in circulating DHT. Clinical studies have investigated its effectiveness in improving hair count and hair thickness in men experiencing pattern hair loss. However, results vary between individuals, and treatment requires consistent medical supervision.

Dutasteride is not suitable for everyone and may cause side effects, including decreased libido, erectile difficulties, ejaculation changes, and breast tenderness or enlargement. Its effects on DHT can persist for an extended period because the medication has a long half-life. It may also affect prostate-specific antigen (PSA) test results.

Dutasteride is generally considered an off-label treatment for hair loss in many countries. A qualified healthcare professional should assess its suitability, discuss potential risks, and monitor treatment when appropriate. It should not be used during pregnancy, and pregnant individuals should avoid handling leaking capsules due to potential risks to a developing male fetus.\