5-HTP (5-hydroxytryptophan) is a metabolite of the amino acid tryptophan. You may know tryptophan as the agent in turkey that makes you feel like taking a nap after Thanksgiving dinner (in addition to a full belly). 5-HTP is a direct precursor of the important inhibitory neurotransmitter serotonin, which is secreted in response to mood or emotion swings. Serotonin soothes and calms and brings about feelings of contentment.

Is 5-HTP safe to take? The FDA has warned that it has found batches with impurities similar to the Japanese batches of tryptophan in 1980.

5-HTP and tryptophan are not the same. 5-HTP is related to tryptophan, but is derived from a different source. The 1980 scare concerning the Japanese tryptophan was attributed to a large batch the Japanese produced that was contaminated during the fermentation and/or filtration process. The contaminant caused affected persons to develop symptoms of EMS (eosinophilia-myalgia syndrome). 5-HTP, unlike tryptophan, is now extracted from the seed of the Griffonia simplicifolia plant and is not produced via bacterial fermentation, virtually eliminating further occurrence of EMS. Although there have been a couple of cases of EMS–like symptoms arising after 5-HTP supplementation, no direct correlations have established, and EMS can occur on its own.