I am haveing trouble sleeping and someone recommended melatonin, what are the pros an cons of taking this?

Unregulated: Melatonin is not regulated meaning you don't know what you're getting. It isn't particularly helpful for sleep since it's short acting and inconsistent. A better choice is rozerem (ramelteon) - a prescription drug which mimics the effects of native melatonin in the brain and allows normal sleep to occur.

Melatonin: Pro's- it is very effective for many people w insomnia. It can be purchased over the counter. Con's- although safe- there are potential se's. Possible se’s from melatonin include: feeling tired the next day, sleep walking, nightmares, vivid dreams, dizziness, confusion, headache, GI upset, v libido, v sperm count, gynecomastia in men & mood changes.