Younger men who take a common drug to treat baldness may have more problems in the bedroom, new research suggests.

Northwestern University researchers found that exposure to low-dose Propecia (finasteride) tripled the likelihood of impotence and conferred almost a five-fold increase in the frequency of prescriptions for Viagra and other sexual-performance drugs and diagnoses of low libido, MedPage Today reports.

"There is a high statistically significant risk of all measured outcomes – impotence … and diminished libido in men younger than 42 who were prescribed finasteride at a dose of less than or equal to 1.25 mg/day for androgenic alopecia compared to men who had no exposure," said Tina Kiguradze, of the Feinberg School of Medicine at Northwestern.

"Detected safety signals indicating risks of impotence and diminished libido for the use of finasteride in the management of androgenic alopecia support the need for increased awareness in both patients and prescribers."

The findings, presented at a meeting of the American Academy of Dermatology meeting, are based on an analysis of more than 1,400 men 42 or younger including 52 who used Propecia.