I forgot to mention, I take the L-Tryptophan about an hour before bed and it makes falling to sleep really easy.
The dosage I was told years ago was 500 mg for each 50 pounds of weight. I take 2000 mg's an hour before bed, on an empty stomach, usually, though I don't believe L-Tryptophan is nearly as sensitive to food than L-Tyrosine. If I have had any food within a couple hours when taking L-Tyrosine, I do not feel it at all! It's REALLY hard to absorb for me at least..