The drug that treats baldness, Propecia (finasteride) has been shown to cause decreased sperm count levels in a recent study by researchers at Mount Sinai Hospital, Toronto, Ontario, Canada.
On average, sperm counts rose 4-fold and as much as 12-fold in men who stopped taking the drug, reported Keith Jarvi, MD and co-authors of the study in the journal Fertility and Sterility.
Records of 4,400 men seen at an infertility clinic were reviewed and 27 (0.6 percent) were taking finasteride 1 mg/d for alopecia areata, a form of hair loss. Three men were excluded from the study and the remaining 24 were evaluated. The authors found that 14 of the 24 men had semen analyses before and after discontinuation of finasteride.
Sperm count increased significantly from an average of 32.34 to 127.62 M/mL, about four times the amount. In nine of the men who were oligospermic (having very low levels of sperm) sperm counts increased 11.6 fold after they stopped the finasteride.
It is not known whether the increased sperm counts would be high enough to cause pregnancy but researchers feel that bringing sperm count levels up may offer some options of less invasive fertility treatment.
As I researched about finasteride affecting sperm count, I was surprised to find that there is an entire other set of side effects that may be due to the use of Propecia.
KPBS.org and Times Healthland both reported finding that the drug Propecia can cause sexual side effects such as problems with libido, ejaculation and orgasm which can continue after the drug is discontinued and may last for months or even years.
The FDA updated the warnings about sexual side effects on finasteride in April, 2012, reported Times Healthland.
This was based upon their review of 421 post-marketing reports of Propecia for sexual side effects from 1998 to 2011. There were also 131 cases of erectile dysfunction and 68 causes of decreased libido from 1992-2010 for the drug Proscar, a drug that treats enlarged prostates and that has higher levels of finasteride.