Taking it nightly for a year was no better than only when needed
After nerve-sparing prostate removal, 100 men took 50mg of sildenafil either every night or only when they wanted it. Erectile function came out the same on every measure.
What the study found
A year of nightly dosing matched taking it only when needed
After nerve-sparing prostate removal, 100 men took 50mg of sildenafil either every night or only when they wanted it, for a year. Erectile function came out indistinguishable on every measure and at every timepoint. Fifteen trials in men with diabetes found the same.
The caveat · No comparison against no drug
Neither body of evidence included a no-drug arm, so this says which schedule to pick and not whether either beats nothing. The prostatectomy trial took men who were fully potent beforehand and kept both nerve bundles, the group likeliest to recover anyway. A null in 100 men is not equivalence.