interesting....
NEW YORK (Reuters Health) - While most people have heard that melatonin makes you drowsy, many could be surprised by a report that suggests the hormone can perk up a male's sex life--at least for rats, according to researchers in Italy.
"In men, a deficient production of melatonin may be related to impaired sexual activity," particularly in impotence that stems from a psychological problem, Filippo Drago and Lina Busa of the University of Catania Medical School, report in the journal Brain Research.
The investigators found that when rats that had shown no interest in sex were injected with low doses of melatonin, they became sexually active. Likewise, rats that showed an interest in sex but were unable to ejaculate were able to do so after melatonin injections. Melatonin "may restore sexual activity in impotent animals by interacting with brain receptors," the authors write.
"This is the first evidence that a naturally occurring substance may restore the full pattern of sexual activity in impotent male animals," Drago and Busa report.
Some people who have taken melatonin as a sleep-inducing aid have found that it makes them more sexually aroused, but evidence of this effect is purely anecdotal, the researchers note.
"If these findings can be confirmed in men, they could be of clinical importance," the authors conclude.
Previous research has shown that melatonin plays a role in regulating the sleep-wake cycle in humans. Levels of melatonin fluctuate with time of day--about 10 times more is released at night by the brain's pineal gland. An oral dose of melatonin resets the body's clock, causing sleepiness in humans.
SOURCE: Brain Research 2000;878:98-104.