I took melatonin pills at night for a couple years to help me get to sleep. They work! Problem is, 5 years ago I started getting terrible joint paints - so bad I couldn't open a door, hold a can of Coke or Drive. I ended up at a rheumatologist who told me I had an autoimmune disease, and melatonin was the likely culprit. Turns out those little over-the-counter supplement pills have THOUSANDS, nay, tens of thousands, of the amount of melatonin as your body is supposed to have, and it's a hormone; it affects many systems in the body. It is not some harmless little sleep aid or health enhancer. Oh well, too late, at least for me: once you have an autoimmune disease, it never goes away, it can only be managed. Beware of anything and everything related to melatonin; I speak from experience.

[Posted by: Lance at October 31, 2008 11:31 PM]

There is some question as to the exact mechanism there. It may be the case that melatonin speeds an existing progression towards autoimmunity by enhancing immune action in general. For example:

http://pmid.us/15589043

[Posted by: Reason at November 1, 2008 8:04 AM]

Lance....same thing with me kind of
Developed knee pain and swelling in both knees following a blow to the right knee 6 years ago. Not only didnt go away but spread.Lotta pain in multiple joints now but no swelling and specialist won't diagnose without swelling. Was taking melatonin at the time but don't know wheather that was the proximate cause.

[Posted by: dougk at February 4, 2009 9:17 PM]