Dutasteride, which is commonly marketed under the brand name Avodart, belongs to a class of drugs called 5-alpha-reductase inhibitors, which block the action of the 5-alpha-reductase enzymes that convert testosterone into dihydrotestosterone (DHT). The drug was approved by the FDA for the treatment of prostate enlargement in men in 2002.



Avodart has not been approved for the treatment of hair loss, although physicians can use an approved medication in ways other than that it was specifically approved for. That said, the use of dutasteride certainly requires doctor supervision. Avodart is used mostly for men who have an enlarged prostate.

If your prostate is smaller, it will put less pressure on your urethra. AVODART has been shown to improve symptoms after 3 to 6 months, with continued improvement extending to 2 years, and this improvement can be maintained up to 4 years. By shrinking the prostate, it stops the symptoms associated with prostate enlargement from getting worse.

Like finasteride (the active ingredient in Propecia), dutasteride blocks the enzyme 5 alpha-reductase that converts testosterone to DHT (DHT causes hair loss). Unlike finasteride, which only inhibits the Type I form of the enzyme, dutasteride inhibits both the Type I and Type II forms. This combined effect lowers circulating DHT more with dutasteride than with finasteride, but also increases the incidence of side effects.

The Type II form of the enzyme (blocked by finasteride) is found predominantly in the hair follicle. The Type I form of the enzyme has been found in the scalp and sebaceous glands, but its exact role in hair growth has not been determined. It is felt that the ability of dutasteride to lower serum levels of DHT is what makes it a more potent medication in hair loss.

When considering the safety of dutasteride, one should consider several facts. It acts on other parts of the body besides the hair follicle. Unlike finasteride, where families that had a deficiency of the Type II 5-alpha reductase enzyme were followed for years without any adverse effects, there is no natural biologic model to show the safety of dutasteride.

Avodart has been approved for prostate enlargement in an older male population. It is not approved for hair loss and, in fact, the clinical trials for hair loss were discontinued, so there is no safety data for its use in younger patients. There is a greater incidence of sexual side effects with dutasteride compared to finasteride.

I hope you have found this information helpful. In any case, you should consult your physician before using Avodart. It may or may not be appropriate, depending on your medical situation, to use the drug to treat hair loss. Be sure to disclose to your physician any other drugs you might be taking before requesting a prescription for Avodart.