The New Jersey-based pharmaceutical company Merck & Co. has been manufacturing Propecia (finasteride) for more almost 2 decades now to help men who suffer from male pattern baldness. Propecia, originally approved by the FDA in 1997, is also marketed in higher doses as Proscar to treat men with an enlarged prostate. However, when Merck discovered that it also caused hair to grow, they began to work on a drug specifically designed to help men grow back their hair.

Propecia and Proscar both belong to a class of drugs called 5-alpha-reductase inhibitors. What this class of drugs does is to block the body from changing testosterone into dihydrotestosterone (DHT), thereby increasing levels of testosterone and lowering levels of DHT. DHT plays a huge role in sexuality and sexual development, and lowering levels of DHT allows more hair regrowth and less hair loss.

Unfortunately, there have been serious side effects linked to the use of Propecia, including sexual side effects that could be permanent. During a 13 year period, the FDA received almost 60 reports through their Adverse Event Reporting System (AERS) of sexual dysfunctions that lasted longer than 3 months after a patient stopped taking Propecia. The conditions reported to the FDA included erectile dysfunction, decreased libido, ejaculation issues, and orgasm disorders.

As of this date, there have been no definite causal links between Propecia and sexual side effects. However, the frequency and number of reports caused the FDA to request Merck change Propecia’s label in April 2012. The warnings the FDA requested Merck include were warnings about sexual side effects, including libido disorders, ejaculation disorders, and orgasm disorders that remained even after the patient discontinued the drug.

As a result of the permanent side effects suffered by men who used Propecia, lawsuits began to be filed in 2012 against Merck & Co. in New Jersey State Court. Many of the lawsuits were later transferred to a multidistrict litigation (MDL) in the U.S. District Court for the Eastern District of New York. Currently, there are over 1,100 pending lawsuits against Merck arising out of the use of Propecia, and the first trial in the MDL is scheduled for October 2016.