As an amino acid, L-tryptophan (also known as tryptophan) is important for building proteins. The body also uses it to make:
- Serotonin, a neurotransmitter that plays an important role in depression and anxiety
- Niacin (a vitamin)
- Melatonin (a hormone).
Although it is found naturally in many foods, L-tryptophan can also be obtained through dietary supplements. These supplements are claimed to be useful for treating a variety of conditions, such as:
- Premenstrual syndrome (PMS)
- Attention deficit hyperactivity disorder (ADHD).
However, more research is needed to prove the effectiveness of L-tryptophan for these uses. In addition, there is some concern that the supplements are not safe for public consumption, as they may cause a dangerous condition known as eosinophilia-myalgia syndrome (EMS).
(For more detailed information on this supplement, including why it was briefly banned in the United States in the early 1990s, click L-Tryptophan.)