Avodart is not primarily a hair loss drug but a prescription-only, FDA-approved treatment for Benign Prostatic Hyperplasia (BPH), a non-cancerous enlargement of the prostate glands fairly common among men aged 50 and above. Avodart inhibits both Type I and Type II 5-alpha reductase (5-AR), an enzyme commonly believed responsible for the conversion of testosterone to 5-alpha-dihydrotestosterone (DHT). Many experts believe that DHT is the main androgen responsible for prostate growth as well as male-pattern baldness.

• Women and children should not use Avodart.
• Men using Avodart should not donate blood until at least 6 months after the medication was last used.
• Men with liver problems should not use Avodart.
• Possible side effects include sexual impotence and a drop in libido