What Are Anti-Androgen Systemic Drugs?

The hormones that are known to promote or trigger hair loss in men and some women are primarily testosterone and its metabolite, DHT. Anti-androgen systemic pharmaceutical drugs are administered orally to treat common balding in men (male androgenetic/pattern hair loss) and female pattern hair loss. They include several different types that act in specific ways to limit the hair loss effects of androgen hormone activity:^(22, 30)

• 5α-reductase inhibitors (e.g., finasteride and dutasteride)
• Adrenal gland suppressors (e.g., dexamethasone, prednisone, deflazacort)
• Androgen receptor antagonists (e.g., cyproterone acetate, spironolactone, flutamide, and drospirenone)
• Ovarian anti-androgens (e.g., oral contraceptives, gonadotropin-releasing hormone agonists, ethinyl estradiol)

Anti-androgen drugs are also used to treat hirsutism and hypertrichosis in women, which are conditions of excessive terminal hair growth in areas where typically vellus hair grows (e.g., the face). This is because androgens act at the follicle-level, and different areas of the body respond in site-specific ways to excess androgens. So while on the scalp excess androgens can cause hair loss, on the face it can cause beard growth in women. Sometimes female patients can actually present with hirsutism and male pattern balding.⁽¹⁵⁾

These androgen effects can occur in both men and women since both genders produce androgen hormones. However, there are gender differences in the hair loss mechanisms of these anti-androgens, and only 5α-reductase inhibitors are used in men. Typically there are accompanying or underlying factors and not the androgen levels by themselves which cause hair loss.^{(22, 30, 196)}