Note from Colleen...I don't know why anyone would want to take L-tryptophan anyway.  It's not banned in Canada, but to get anywhere near therapeutic doses you have to take a massive dosage ... and just try to SWALLOW those horse pills!  LOL - been there, done that!

And Terry, I'd just add that what you should be using -- tryptophan or otherwise -- depends on what your target symptom is.  If it's sleep, as I'd guess from your question, that's usually a marker indicating there's more trouble out there than just sleep: usually people are having other symptoms like irritability, mood lability (like easy tears), and agitation/anxiety symptoms too. If that's the case, then the pills we know help a lot of people, and help more than a placebo, are the mood stabilizer medications.  You can try other stuff, but if you haven't had treatment with a combination of mood stabilizers and no antidepressant in the mix, then you haven't had "standard treatment" yet.  Out of hundreds, I only have four patients that did not get much better with "standard treatment".  

Dr. Phelps