What do the states mean?+
- Solid: well studied, and it works.
- Half-there: the science is still forming.
- A ghost: almost no real studies.
- Hollow: well studied, and it does not work.
- A cord: the pair itself has been tested together.
- Air: nobody has ever tested this pair.
The full scoring method: How we score
5-HTP benefits: where the science stands
For mood: not settled yet.
Mood is what most people take 5-HTP for, and the best studies disagree: one found it helps, one found no effect. As of August 2026, the verdicts on this page rest on evidence from 5 trials, drawn from the strongest research among the 90 papers on PubMed that mention 5-HTP. Every claim is checked below.
90 papers on PubMed · evidence from 5 trials
Claim by claim
- MoodThe science is still forming. The best studies disagree.
- Energy and fatigueThe science is still forming. No real difference found so far.
- Memory and focusThe science is still forming. The best studies disagree.
- SleepAlmost no real studies. What exists leans positive.
See 2 more scored claims+
- Stress and anxietyThe science is still forming. No real difference found so far.
- Weight and body fatAlmost no real studies. What exists leans positive.
Pairs people ask about
The five sources we read
- 2022Crossover trial · 166 people · no clear effect on energy and fatigue; no clear effect on mood; no clear effect on stress and anxietysource
- 2023Randomized trial · 48 people · benefit for weight and body fatsource
- 2024Randomized trial · 30 people · benefit for sleepsource
- 2025Randomized trial · 30 people · benefit for memory and focus; benefit for mood; no clear effect on stress and anxietysource
- 2026Randomized trial · 112 people · no clear effect on memory and focussource
Chosen as the strongest evidence out of 90 papers on PubMed. Every row links to its paper.
Fair questions
Does 5-HTP work?+
For mood, it is not settled. The best studies disagree.
Is 5-HTP safe?+
No caution is recorded on this page. That is not a safety guarantee; the studies we read were not safety trials.
How many studies exist?+
90 on PubMed for 5-HTP itself; the count is measured from PubMed, not estimated. We read the five strongest and linked every one above.