Tryptophan Shunting

For patients with an inflammatory picture, 5-HTP supplementation is preferable to tryptophan, which may be redirected toward neurotoxic quinolinic acid. Chronic inflammation redirects tryptophan away from serotonin synthesis and toward the kynurenine pathway. Under normal conditions, tryptophan is converted to 5-HTP and then to serotonin when B vitamin and mineral cofactors are adequate. The organic acids test can directly measure quinolinic acid levels, confirming tryptophan shunting toward the neurotoxic pathway.