L-tryptophan is an essential amino acid that you must obtain by eating protein-rich foods or taking supplements. L-tryptophan has several important roles in health, including helping to create the neurotransmitter serotonin. Like serotonin, gamma-amino butyric acid, or GABA, is a neurotransmitter. GABA as a supplement has various purported benefits, such as being helpful for weight loss. Consult a qualified health-care provider before taking L-tryptophan or GABA supplements.
GABA is an inhibitory neurotransmitter, which means that it calms brain activity. Drugs that have similar effects or that boost GABA levels in the brain are useful for treating disorders such as epilepsy, anxiety and depression. GABA supplements are promoted as useful for relieving anxiety, depression, pain and symptoms of premenstrual syndrome. They also are claimed to promote weight loss, increase exercise tolerance and reduce high blood pressure. Little scientific evidence supports the use of GABA supplements for any health problem, however, according to eMedTV.
Your body uses L-tryptophan to balance nitrogen levels and for the manufacture of niacin and serotonin. Proper serotonin levels are connected with healthy sleep and mood stability. L-tryptophan may help with some of the conditions for which people take GABA, such as relieving sleep problems, anxiety, depression and symptoms of premenstrual syndrome. L-tryptophan interacts with numerous substances, but GABA is not one of them.
GABA supplements are not indicated as interacting with any supplements or drugs, but eMedTV cautions that research on this point is lacking. Because L-tryptophan boosts serotonin levels, it has potential serious interactions with other substances that have this effect. High levels of serotonin can be dangerous. Prescription antidepressants, for example, increase serotonin levels, and the supplement St. John's wort does as well. GABA does not increase serotonin, and should not cause problems if you take it with L-tryptophan. Ask your health-care provider for guidance first.
Supplemental L-tryptophan can cause digestive effects such as lack of appetite, heartburn, burping, gas, nausea and diarrhea. It also may cause drowsiness, light-headedness, blurred vision, lack of coordination and headaches. GABA is not connected with any side effects when taken as an oral supplement, according to eMedTV. It should not cause additive side effects when taken with L-tryptophan.