I spent years trying to find the best product out there.
In the Uk they have a product called wintersun complex which combines, it is quickly being regarded as the best product out there.:
Vitamin D3 (5000iu),
5HTP (100mg),
l-tryptophan (500mg),
Magnesium Chelate (200mg),
Vitamin B Complex - 75mg
and Vitamin C - 1000mg.
I think it was found at www.wintersuncomplex.com
I found this if its any help to you.
Toxicity can occur if too much is taken.
http://www.cmaj.ca/cgi/reprint/169/1/47.pdf
Hope that helps.