Melatonin

 

Influences Sex Steroids

 

Melatonin is a hormone released by the pineal gland that helps regulate sleep. Many animals reproduce better during periods of greater sunlight because they produce less melatonin. University of California, Berkeley researchers— in a study on birds— found that sex hormones were lower when melatonin levels were higher (during longer periods of darkness). Many bodybuilders take melatonin supplements to promote sleep. If the results of this study apply to humans, overuse of melatonin supplements could depress natural testosterone production. (Endocrinology, published online)