Propecia and Avodart are two popular hair loss treatments for men. The two work in similar fashion to combat hair loss, although only Propecia is approved by the U.S. Food and Drug Administration as a hair loss treatment. Avodart can be prescribed for hair loss as an off-label prescription, but as of 2010 is only approved by the FDA as a treatment for an enlarged prostate.
Propecia is a 1mg tablet of finasteride. Finasteride was originally developed as a treatment for benign prostatic hyperplasia and a 5mg version of finasteride, Proscar, is still sold as a treatment for enlarged prostates. In 1997, Propecia was approved by the FDA as a hair loss treatment.
Avodart, which is the trade name for dutasteride, is intended to be a treatment for benign prostatic hyperplasia. It was approved by the FDA as a prostate treatment in 2001.
Both Propecia and Avodart prevent testosterone from being converted into DHT. The culprit behind the conversion is an enzyme known as 5-alpha reductase. DHT will attach itself to hair follicles and over time cause them to shrink, which prevents new hair from being able to grow.
There are two types of 5-alpha reductase and one major difference between Propecia and Advodart is that Propecia can only inhibit Type II 5-alpha reductase, while Advodart is the first drug that inhibits both types from making the conversion to DHT. As a result, Advodart is more effective in lowering DHT levels in the body. A study that appeared in the Fall, 2005 issue of the journal "Reviews in Urology" found that dutasteride lowered DHT serum levels by more than 90 percent, compared to a 70 percent reduction with finasteride.
The ability to lower DHT levels more than finasteride has shown dutasteride to be a more effective product for hair regrowth. A study by the Duke University Medical Center that appeared in the December 2006 issue of the "Journal of the American Academy of Dermatology," concluded that 2.5 mg of dutasteride was superior than 5 mg of finasteride for increasing hair count.
The length of time both drugs stay in your system is another key difference between the two products. According to Grey Hair Loss, Propecia will stay in your body for approximately one day, while Advodart stays in the system for several months.
Avodart is the more expensive drug of the two. As of Sept. 6, 2010, a 90-day supply of Avodart from drugstore.com is $337.04, while a 90-day supply of Propecia costs $184.99.
Both drugs are intended for use in men only. Women who are pregnant or may become pregnant are advised not to touch either pill due to the potential of birth defects in the unborn child. Those taking Avodart should wait a minimum of six months before donating blood after discontinuation of the drug. This is to prevent the possibility of a pregnant woman receiving blood with traces of the drug still present.