Is 5-HTP the next magic pill?

O, The Oprah Magazine, July 2005

WHY THE BUZZ: Advocates claim that boosting your levels of 5-hydroxytryptophan (5-HTP) is a natural way to ease such chronic problems as depression, insomnia, and migraines. Because 5-HTP is a chemical precursor of serotonin, a neurotransmitter that regulates all of these conditions, proponents of the supplement claim that it works by increasing serotonin in the brain. A spate of books pushing 5-HTP may have led to its recent surge in sales.

THE SCIENCE: When researchers at the University of Queensland School of Medicine in Australia did a comprehensive review of 5-HTP studies, they came up with little evidence that the supplements, on their own, relieve depression. Most of the 5-HTP in a supplement is converted to serotonin in the intestines and never gets as far as the brain. But when taken with a prescription drug used in patients with Parkinson's disease (called a decarboxylase inhibitor), which helps it reach the brain intact, the combination can be an effective antidepressant. A few small studies imply that 5-HTP alone may ease insomnia and reduce migraines, but the results are hardly definitive.

THE DRAWBACKS: When someone takes 5-HTP without the decarboxylase inhibitor, her gut produces too much serotonin. This surplus can't cross into the brain, but it can cause nausea and diarrhea. "Lower doses aren't going to work," says Simon Young, PhD, a neuropharmacologist at McGill University in Montreal. "And higher doses will almost certainly give you stomach upset."

SHOULD YOU TAKE IT? Probably not. It likely won't do much but make you feel sick. And given that the FDA doesn't regulate supplement production, there are real safety questions. In 1998, for instance, the FDA and the Mayo Clinic issued a warning that a dangerous impurity had been found in 5-HTP supplements. Since prescription drugs that alleviate migraines, insomnia, and depression exist, they may be the better choice.