Tryptophan
Level 4 — Significant concernsIn Winter's Dictionary
Tryptophan is a amino acid — Essential amino acid and serotonin precursor
What it does
Essential amino acid and serotonin precursor
Where you'll see it
creams, lotions, supplements
What the research says
Not completely harmless; suspected carcinogen; affects liver in high doses; causes cancer in experimental animals
Benefits
Partial precursor of serotonin
Regulatory status
- US FDA: ASP
- Notes: Suspected carcinogen; FDA called for further study
Sources
- A Consumer's Dictionary of Food Additives (Winter): causes cancer in experimental animals; the FDA called for further study of this additive