Though men who participated in clinical trials found that Dapoxetine was effective in treating their premature ejaculation, the FDA is unlikely to approve the drug due to its potentially harmful side-effects.

If the US Food and Drug Administration finds it safe and effective, Dapoxetine will become the first drug specifically approved for premature ejaculation.

Dapoxetine is a short-acting selective serotonin reuptake inhibitor (SSRI) -- a class of drugs that have been used off-label to treat the condition.

They have been known to produce side-effects including psychiatric problems, dermatological reactions, weight gain, reduced libido, nausea, headache and weakness after long-term use, which casts considerable doubt over whether Dapoxetine will gain the agency's nod. In fact, the agency rejected Dapoxetine last year.

Lead researcher Jon Pryor of the University of Minnesota and colleagues looked at data from two studies involving a total of 2,600 men who had moderate to severe premature ejaculation. Their average time of ejaculation was less than one minute after vaginal penetration. The average age of the group was just over 40.

Half the men took Dapoxetine and the other half took a placebo one to three hours prior to having sexual intercourse. Those who took Dapoxetine experienced lengthened ejaculation time and greater control, the investigators reported.

Those who took a 30-milligram dose of Dapoxetine over a three-month period increased their ejaculation time to 2.78 minutes after penetration, on average, while those who took a 60-milligram dose experienced an increase to an average of 3.32 minutes. The placebo group averaged 1.75 minutes before ejaculating after three months.

Among those on the 60-milligram dose, approximately 20 percent experienced nausea. Other side-effects reported include diarrhea, headache and dizziness.

The researchers characterized Dapoxetine as "generally well tolerated" and said it improved ejaculation time "significantly."

Premature ejaculation is more prevalent than impotence, affecting between 21 percent and 33 percent of all men.