An ABC News Report showcased a new study indicating that the popular male pattern baldness treatment finasteride, known commercially as Propecia, may have negative effects on sexual function long after a man has stopped taking it.

The Propecia study published in the Journal of Sexual Medicine finds that side effects may not only continue after stopping finasteride, but they may last for months or even years.

In the study, Dr. Michael Irwig of George Washington University and his colleagues surveyed 54 men under the age 40 who reported experiencing side effects for three months or more after stopping the hair loss medication Propecia.

The patients reported a variety of sexual problems including Propecia erectile dysfunction, low libido, trouble having an orgasm, and shrinking and painful genitals. Some men also reported neurological problems like depression, anxiety and cognitive haziness.

For 96% of the men, the sexual problems lasted more than a year after they quit using the hair loss remedy. None of the men had sexual, medical or psychiatric complaints before taking Propecia.

The study sample was small and the authors acknowledge that it may be skewed to include only men who were most negatively impacted by the drug. Many of the men in the study had participated in an online Propecia forum dedicated to helping men deal with the side effects of the hair loss medication. Because of this, the group of men studied may not fairly represent all those who take the medication and experience finasteride side effects.

Still, the authors argue their findings may signal potentially serious risks for men using finasteride. “Our findings make me suspicious that this drug may have done permanent damage to these men,” Irwig told ABC News.

However, Irwig noted that because he enlisted study participants from a website where people report sexual problems from Propecia, it’s possible that his study sample contained a disproportionate number of people severely affected by the drug, ABC News reported. And overall, he noted that the total number of people who will even have these kinds of side effects is low, or about 3 percent.

Additionally, Irwig cautioned that more research is needed to determine whether men who take Propecia and do not experience sexual side effects also have depression and suicidal thoughts.

Propecia Lawsuits

In 2012, the Food and Drug Administration (FDA) updated the warning to finasteride, Merck’s drug marketed to treat both male pattern baldness (Propecia) and enlarged prostate (Proscar). The new warnings noted that the sexual side effects associated with the hair loss medication, including problems with libido, ejaculations and orgasm, could last even after patients stop taking the drug.

Further, in April 2012, a federal judicial panel transferred Propecia lawsuits pending in federal courts to the U.S. District Court for the Eastern District of New York. Each of those Propecia lawsuits was filed against Merck and alleged that Propecia caused “persistent sexual dysfunction.”

To date, over 1,100 men across the country have filed Propecia side effects lawsuits against Merck seeking compensation for these complications.

The Propecia MDL is In Re: Propecia (Finasteride) Product Liability Litigation, MDL No. 2331 in the U.S. District Court for the Eastern District of New York.