http://en.wikipedia.org/wiki/Melatonin



"There is evidence that melatonin is safe with short term use." eg three months or less

Some unwanted effects in some people, especially at high doses (~more than 3 mg/day) may include: headaches, nausea, next-day grogginess or irritability, hormone fluctuations, vivid dreams or nightmares[2] and reduced blood flow (see below).

[此贴子已经被作者于2008-7-13 0:37:48编辑过]