In January 2012, The Journal of Sexual Medicine published an analysis of 14 previously-published peer-reviewed studies on ED drugs and premature ejaculation treatment. The authors found that half the studies considered ED drugs effective on their own. Two studies found the drugs not helpful at all. Others found that ED drugs were helpful when combined with other medications or with behavioral therapy.
However, the authors had difficulty reaching a definitive conclusion based on these studies. Not all the studies defined premature ejaculation the same way and over half of them did not compare the ED drugs to a placebo. (This comparison is an important one, as it shows whether the drug is actually causing the results.)
Even though they did find some promising results, the authors concluded that there still isn’t enough evidence to support the use of ED drugs to treat premature ejaculation. However, future research may help.