Tryptophan (also known as
L-tryptophan) is an amino acid found in many foods and also used in
dietary supplements. As with most supplements, people use tryptophan for several different conditions. Tryptophan supplements are sometimes claimed to help for the following purposes:
Tryptophan is also sometimes used to help people quit smoking and to enhance athletic performance.
Early research suggests that high-dose tryptophan supplementation may work for premenstrual dysphoric disorder (PMDD) and for helping people quit smoking (when used in combination with group therapy). Very early studies suggest that tryptophan supplements can help improve the effectiveness of conventional antidepressant medications. However, larger studies are necessary before it can be suggested that tryptophan is effective for these uses.
Studies have shown that tryptophan supplementation is probably not effective for teeth grinding or for improving athletic performance. Also, even though research has shown that children with ADHD have low tryptophan levels in the body, giving them tryptophan supplements does not seem to help with ADHD symptoms.
There is not enough evidence to prove that tryptophan is effective for other uses, such as for anxiety or Tourette syndrome.