Premature Ejaculation
According to the famous sex researchers Masters and Johnson, premature ejaculation is when the man ejaculates before his partner has had an orgasm 50% of the time or more. Before that, researchers had defined it as ejaculation within two minutes of penetration, until in the 1960s Alfred Kinsey showed in a survey that over two thirds of men self-reported as ejaculating within two minutes. In contemporary times, premature ejaculation is defined much more fluidly, and with particular reference to the emotional satisfaction of the man and his sexual partners.
Most men experience premature ejaculation at least once in their lives, and this is nothing to be concerned about unless it forms the basis of a repeating pattern. There are a number of ways to deal with the problem, among them kegel exercises, which involve tightening the muscles that close the penis, serotonergic drugs, and simply finding other ways to satisfy your partner before penetrating so that it matters less how long you last. A nutrient very useful in the prevention of premature ejaculation is 5-HTP, which is a serotonin precursor--the presence of serotonin in the brain is shown to delay ejaculation.
