"Just like urinating or lacking bowel control when we are babies, I think ejaculation is a behavior that we learn to gain control of," says Irwin Goldstein, MD, director of San Diego Sexual Medicine and the editor in chief of The Journal of Sexual Medicine. "Some people cannot learn to gain control (of PE), and the research into the causes is not definitive."
How long should sex last?
But what's a "normal" amount of time to wait for ejaculation? The Journal of Sexual Medicine published a study in 2005 that had 1,587 women time sex with a man from initial penetration to climax and found that the men diagnosed with premature ejaculation climaxed in an average of 1.8 minutes, while the others performed for an average of 7.3 minutesa difference of just five and a half minutes.
Some link PE to hyperthyroidism, a condition in which the thyroid gland produces too much of the thyroid hormone thyroxine, which regulates the body's metabolism. A small study in the December 2005 issue of the Journal of Clinical Endocrinology & Metabolism found that 50% of men with hyperthyroidism complained of PE.
Ira Sharlip, MD, spokesman for the American Urological Association and clinical professor of urology at University of California at San Francisco, is not so sure. He blames PE on "subtle abnormalities in serotonin metabolism" and, in some cases, psychological factors. Serotonin is a neurotransmitter that regulates many functions, including mood, appetite, and sensory perception.