5-HTP vs Tryptophan

Introduction

Both 5-HTP (5-hydroxytryptophan) and L-tryptophan are precursors to serotonin — the neurotransmitter central to mood, appetite, and sleep regulation. They are often sold interchangeably, but they are not the same molecule and do not behave identically in the body.

The Biochemical Difference

Tryptophan is an essential amino acid; the body converts it first to 5-HTP, then to serotonin. 5-HTP skips the first step, meaning it more directly influences serotonin levels. However, tryptophan has an additional pathway: it can also be converted to niacin (B3) and proteins, giving the body more metabolic flexibility.

What the Research Shows

For depression: 5-HTP shows modest efficacy in Cochrane-reviewed trials, though not at the level of prescription SSRIs. For sleep: tryptophan is superior because it also promotes melatonin synthesis via the pineal gland, improving REM sleep duration.

Dosage & Safety

5-HTP: 50–300 mg/day in divided doses. Tryptophan: 500–2,000 mg before bed. Both carry a real risk of serotonin syndrome if combined with antidepressants (MAOIs, SSRIs, SNRIs). Start low and never mix without medical supervision.

Verdict

Choose 5-HTP for mood support and tryptophan for sleep. Neither is a replacement for professional mental-health treatment, but both are useful adjuncts when used responsibly.