Tryptophan is an amino acid. Amino acids are the basic building blocks of all the protein in your body and in your food. Tryptophan is an essential amino acid, which means that you must get it from the foods you eat, because your body cannot produce it. Because of tryptophan's functions in the body, supplemental doses may help promote sleep.
When scientists study amino acids, they shine lights through their crystals. If the light is deflected toward the left, the amino acid is given the designation L, notes Dr. Elson Haas, M.D., in his book "Staying Healthy with Nutrition." If the light is deflected to the right, the amino acid is given the designation D. Most naturally occurring amino acids are L-amino acids and tryptophan is no exception. L-tryptophan is the preferred supplemental form.
Tryptophan is essential for proper growth in infants and an optimal nitrogen balance in adults, notes the University of Maryland Medical Center. In your body, tryptophan assists in the production of niacin, a B vitamin, and to perform this function your body must be adequately supplied with iron, riboflavin and vitamin B6. Arguably, tryptophan's most vital function is its role as a precursor for serotonin. Serotonin is a neurotransmitter that may promote not only sleep but also a stable mood, notes Medline Plus. Your body's serotonin levels are directly correlated with your tryptophan intake.
Tryptophan Supplementation for Sleep
L-tryptophan has been used effectively in the treatment of insomnia. Its effectiveness is likely due to the fact that serotonin is essential to induce and maintain sleep. Since L-tryptophan can only be obtained by a prescription from a medical doctor, you should follow your doctor's advice on how to take the supplement. Normally, 1 to 2 g of L-tryptophan are needed to induce sleep, reports Haas. Initially, people usually start with 1 g, taken 30 to 45 minutes before bed. The dose can be increased by 500 mg each night, up to a dose of 3 g, until sleep becomes optimal. Including vitamin B-6 supplement may help with tryptophan utilization.
Tryptophan is more effective for acute insomnia than for ongoing, chronic sleep problems. Therapeutic supplementation of tryptophan should not be used by people with asthma or those with systemic lupus erythematosus, cautions Haas. In general, no side effects have been reported for moderate tryptophan supplementation. However, sleep patterns may be distorted if more than 10 g is taken. The University of Maryland Medical Center notes foods high in tryptophan include cheese, chicken, nuts, fish, milk, peanuts, sesame seeds, tofu, soy, turkey and pumpkin seeds.