I've heard that Melatonin is very hard to study? And that nobody knows how someone will react to it- the reactions range the entire spectrum... I've a terrible problem with jet lag- esp, when we get back to California from India via Singapore- and the last time in desperation I took melatonin for 3 nights- the 3 pills helped me sleep wonderfully and I did great during the day. So I 'highly recommended' it to my brother, my cousin etc. My cousin did the same trip, came back and worked night shift for a week- and was going into a month of day shifts and was desperately trying to sleep at night. She took 1 pill and she was awake the entire night! So I now I am more cautious.... abi (whose Dad has PD 73/2)