I've tried tryptophan (in the form of a metabolic precursor who's name I can not remember right now), but it only works for two days then I get accustomed to it.
What is the difference between taking drugs / taking 5-HTP supplementals / "naturally" getting a lot of tryptophan in your diet? Seems like it's all drugs.
At the end of the article, it was stated that tryptophan in foods does not go to your brain because of other substances competing (and taking priority) for transport resources.