After trading anecdotes with fellow hair loss physicians about how finasteride can reduce body hair in some patients, Sharon A. Keene, M.D. took the next logical step and asked whether finasteride might have a negative effect on patients who have body hair transplant (BHT) procedures.

In a review of scientific literature on whether finasteride effects body hair growth, Dr. Keene finds that current research is inconclusive.

Finasteride, the drug in the hair loss medication Propecia, works by blocking the 5-alpha-reductase type 2 enzyme (5-AR Type 2) which is needed by the body to covert testosterone to DHT. DHT causes common baldness, by making hair follicles shrink and eventually die.

In looking at DHT’s effect on body hair growth, current research strongly suggests that it does play a key role. Males born with a deficiency of 5-AR Type 2, and thus no DHT, have reduced, or absent, body hair growth (and no loss of scalp hair).

It would seem logical then, that when finasteride is used to re-grow hair on the scalp, it would also inhibit the growth of hair on the body. However, the genetic variation among people is too great to determine exactly how much of an influence it plays.

With this uncertainty of DHT’s effects on body hair, it is impossible to say, without further study, if finasteride would have the same effect on body hairs which are transplanted to the scalp. In Dr. Keene’s conclusion, she suggests:

A patient on finasteride for at least a year who undergoes BHT is probably safe to continue it, as remaining body hairs are apparently not sensitive to the effects of this drug.

You can read the full discussion and review of current research in the January/February 2011 issue of Hair Transplant Forum International, the official newsletter of the International Society of Hair Restoration Surgery (ISHRS).

• Read a detailed review on how DHT causes hair loss in men
• Read more about body hair transplants