Other medications with anti-androgen effects include flutamide, and spironolactone, which can give some improvement in hirsutism. Metformin can reduce hirsutism, perhaps by reducing insulin resistance, and is often used if there are other features such as insulin resistance, diabetes, or obesity that should also benefit from metformin. Eflornithine (Vaniqa) is a medication that is applied to the skin in cream form, and acts directly on the hair follicles to inhibit hair growth. It is usually applied to the face. 5-alpha reductase inhibitors (such as finasteride and dutasteride) may also be used; they work by blocking the conversion of testosterone to dihydrotestosterone (the latter of which responsible for most hair growth alterations and androgenic acne).