A new study suggests that the 5-alpha reductase inhibitors finasteride (Proscar, Propecia) and dutasteride (Avodart) are not associated with an increased risk of erectile dysfunction (ED), countering the findings of previous studies. Researchers from the United Kingdom examined the records of 90,000 men with benign prostatic hypertrophy (BPH) or alopecia on a 5-alpha reductase inhibitor alone or with an alpha-blocker, or an alpha-blocker alone. The main outcome was diagnosis of ED or a prescription or procedure for ED. In the BPH group (n = 71,849), the risk of ED was not increased with 5-alpha reductase inhibitor alone (incident rate ratio [IRR], 0.92; 95% confidence interval [CI], 0.85-0.99; odds ratio [OR], 0.94; 95% CI, 0.85-1.03) or in combination with an alpha-blocker (IRR, 1.09; 95% CI, 0.99-1.21; OR, 0.92; 95% CI, 0.80-1.06) compared with alpha-blocker only. Duration of BPH was a risk factor for ED regardless of drug exposure. For alopecia (n = 12,346), 1 mg of finasteride was not associated with ED compared to men with alopecia who were not treated (IRR, 1.03, 95% CI, 0.73-1.44; OR, 0.95; 95% CI, 0.64-1.41). The authors concluded that 5-alpha reductase inhibitors do not seem to increase the risk of ED, regardless of the indication for use (BMJ 2016; 354 doi: http://dx.doi.org/10.1136/bmj.i4823). This study will be a relief for men who take 5-alpha reductase inhibitors, since previous studies suggested ED may be a significant problem with these drugs.