Oxitriptan or 5-HTP is a metabolite of the natural amino acid L-Tryptophan, a component of proteins. In turn it is the immediate precursor of serotonin.It is abundantly found in the seeds of the African plant griffonia simplicifolia (Rondanelli 2012). It is used as an antidepressant, to treat fibromyalgia, neurological disorders, headaches, insomnia and obesity with controversy over the lack of evidence of its effetiveness (MedlinePlus 2016, Shaw 2002, Alt Med Rev 1998). Levels of 5-HTP and tryptophan decrease in the mother during childbirth, while they increase in cord blood (Carretti 2003). Like L-Tryptophan, its use has been associated with a serious epidemic of eosinophilia-myalgia syndrome with more than 1,500 cases and 37 deaths occurring in the 1990s, possibly caused by contaminated or poorly prepared batches of tryptophan (Medline Plus 2016, Klarskov 2003, Klarskov 1999, Michelson 1994). The FDA has not authorized its as a drug. Since the last update we have not found any published data on its excretion in breast milk. Its pharmacokinetic data (low molecular weight, low protein binding, low volume of distribution) make it likely that it would pass into breast milk in amounts which could be significant. It can increase prolactin levels (Lancranjan 1977). Due to the lack of evidence on its efficacy and the possibility of side effects, it is a drug that is non-essential during breastfeeding. If used, very moderate consumption is recommended and and it must come from a reliable source, given the poisonings that have previously occurred (Medline Plus 2016).