Detailed Product Description Specification:5-HTP (5-Hydroxytryptophan) 99% (HPLC),100% pure natural, from griffonia seed ,stable quality ... other supplements (and drugs) that have molecules too large to pass from the bloodstream into the brain, molecules of 5-HTP are ... , or neurotransmitter, called serotonin. In 1994, 5-HTP was introduced in the U. S.; 5-HTP is thought to pose significantly less risk ...