5HTP (5-hydroxytryptophan)
5HTP is an activated form of the amino acid tryptophan, and is a precursor to serotonin. Often referred to as the feel-good neurotransmitter, serotonin is responsible for many of the processes in the brain associated with mood, appetite, and sleep. Its ability to help with appetite control and weight loss has been demonstrated in placebo controlled studies.
One Italian study reported in the American Journal of Clinical Nutrition in 1992 involved obese women who were “hyperphagic”– meaning that they ate too much. This was a randomized, placebo-controlled trial. The experimental group took 300 mg of 5HTP three times per day.
They were first monitored for 6 weeks without any dietary recommendations. The group taking the 5-HTP supplement apparently had less hunger since they decreased their calorie intake significantly. They even cut their carbohydrate intake in half.
During the next 6 weeks, the women were given a prescribed diet to follow. The 5HTP group then decreased their calorie intake even further. The women who took 5HTP were able to lose an average of 5% of their body weight over the full 12 weeks. The placebo group did not lose any weight on the diet.
The dose of 5HTP used in this study (900 mg/day) was higher than usually used or recommended by supplement sellers. The higher dose was associated with nausea, at least initially, but did not show other adverse affects compared to placebo during short term therapy.
5-HTP is also a precursor molecule for melatonin production. When taken at bedtime, melatonin levels rise. This may help with restful sleep, according to some sources.
For weight loss, most supplement manufacturers recommend 50 – 100 mg on an empty stomach, about one hour before mealtime. Note that this is a lower dose than was used in the Italian study reported above.
Who may benefit from 5-HTP? Those who have trouble controlling their appetite, have carbohydrate cravings or food addictions, or mood and anxiety issues may find it to be helpful. Use the smallest effective dose. It is not recommended for long-term use.
Avoid if you are taking any antidepressants that affect the serotonin system. This includes virtually all of them except for buproprion or Wellbutrin. Also avoid 5HTP with St. John’s Wort. High serotonin levels in the brain can lead to serotonin syndrome, a rare but potentially fatal complication of combination therapy.