Finasteride is a pill, approved by the FDA for the use for male pattern hair loss in 1997. Taken once a day in a 1 mg dose, it acts by decreasing the body’s level of (DHT) dihydrotesterone, a metabolite of testosterone that can cause hair loss. Studies have shown that it increases hair diameter, growth rate, and to a lesser degree hair count. Stabilization of hair loss has been reported in studies in 51% of men and hair regrowth in 48% of men. It is generally a very well tolerated medication with adverse side effects being rare and reported in 1-2% of patients. This practice has been prescribing it for many years, with many happy patients.
In 2015, some data was brought to the scientific community’s attention about some undesirable side effects. In large clinical trials, some of the reported side effects include decreased libido, erectile dysfunction, and decreased sperm count. Other side effects reported include breast tenderness, breast enlargement, breast nodules, allergic reactions, testicular pain, depression / suicidal ideation, and rare cases of male breast cancer. Upon the discontinuation of the medication, the resolution of the reported sexual dysfunction side effects has resolved, except in a small subset of patients who have reported permanent sexual dysfunction, which is of obvious concern. Note that permanent sexual dysfunction has not been substantiated in double-blind placebo-controlled clinical trials as all symptoms resolved in weeks to months following the discontinuation of the medication.
Frequently Asked Questions
For over 11 years now finasteride, brand name Propecia, has been used as a very effective treatment for hair loss.
Overall it works in around two-thirds of men to slow down or stop hair loss in the crown region and around one-third of men to do the same thing in the frontal region. In addition, in a small percentage, there is some thickening of the existing hairs giving the appearance of more hair. I have been prescribing Propecia for 11 years and over the past 6 years, ever since the 5-year studies came out, have done so with significant confidence that it is a safe and effective medication.
Side effects are quite small but can include reduction of libido, which is the most common, and occasionally things like breast tenderness or enlargement or testicular discomfort. There also can be a slight reduction in the amount of ejaculate. When patients do experience side effects, I recommend that they reduce the dosage to 1 pill every other day.
I especially like finasteride for those patients with crown hair loss, younger patients who are having a hair transplant, any patient who is having a hair transplant who desires thickening of their donor hairs which thus means the recipient areas would look thicker, or any patient who wants to do everything he can to slow down his hair loss. It is only for men.
Finasteride also affects the levels of PSA (prostate-specific antigen), so the male patient should inform his primary physician and/or urologist of his use of the medication.
Finasteride is only approved for the use in men. If a woman is to become pregnant while taking finasteride, it could cause defects in the male fetus.