Supplement
Supports broad cellular function with category-specific mechanisms.[1582,1652,2116, etc.]
Superscript reference numbers link to the Sources bibliography.
Composite Rating
Blends evidence depth, community direction, safety friction, and completeness.
Evidence Intensity
88/100
High depth from human/RCT/meta counts
Community Direction
-7
Mixed / Neutral • confidence Moderate
Safety Friction
100/100
High signal from adverse/interaction markers
Data Completeness
100%
Studies 11 • mentions 13 • links 22
Not medical advice. This product is for educational and informational purposes only. It does not diagnose, treat, cure, or prevent any disease and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition.
FDA disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Results may vary. Not intended for use by pregnant or nursing women, individuals under 18, or those with known medical conditions without physician consultation.
If you are experiencing a medical emergency, call 911 or your local emergency number immediately.
Goal alignment: Longevity, Metabolic Health, Energy.[199,330,343, etc.]
Dose guide: Human-study daily dose: 100 mg/day (early-confidence extraction from PubMed abstracts)..[199,330,343, etc.]
Category
Other
Evidence Tier
HIGH
Daily Guide
Human-study daily dose: 100 mg/day (early-confidence extraction from PubMed abstracts).
Clinical Depth
Humans: 51 • RCTs: 14 • Meta: 0
Cohort / Real-World
Cohort signals: 0
Safety Markers
Adverse signals: 95 • Interactions: 157
Freshness, trend, and study timeline for this item
Status
Trend
→ Stable evidence base
Depth
159 total studies · 4 recent
Timeline
Animal-only studies
1,455
In vitro / tissue
163
Total indexed
159
Interaction signals
157
Safety adverse signals
95
Human studies
51
Weighted direction score: -7 (Mixed / Neutral)
High when >=2 human meta-analyses, or >=5 human RCTs with substantial human literature volume.
Animal-only studies
1,455
In vitro / tissue
163
Total indexed
159
Interaction signals
157
Safety adverse signals
95
Human studies
51
Randomized trials
14
Meta-analyses
0
Distribution of evidence by study design strength
Evidence Strength: High
Composite of study volume, RCTs, and meta-analyses
PMID 34737364 • 2021 Nov 4
Tryptophan-enriched diet or 5-hydroxytryptophan supplementation given in a randomized controlled trial impacts social cognition on a neural and behavioral level.
Sci Rep
Open PubMedPMID 38309227 • 2024 Mar
The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial.
Clin Nutr
Open PubMedPMID 40944161 • 2025 Aug 27
The Impact of 5-Hydroxytryptophan Supplementation on Cognitive Function and Mood in Singapore Older Adults: A Randomized Controlled Trial.
Nutrients
Open PubMedPMID 35583055 • 2023
The Effects of 5-HTP on Body Composition: An 8-Week Preliminary RCT.
J Diet Suppl
Open PubMedPMID 9705024 • 1998 Jul
Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients.
Int J Obes Relat Metab Disord
Open PubMedPMID 22684569 • 2012 Jun
Neurotransmitter-precursor-supplement intervention for detoxified heroin addicts.
J Huazhong Univ Sci Technolog Med Sci
Open PubMedPMID 33375373 • 2020 Dec 26
5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology.
Int J Mol Sci
Open PubMedPMID 16023217 • 2006 Mar
Serotonin a la carte: supplementation with the serotonin precursor 5-hydroxytryptophan.
Pharmacol Ther
Open PubMedPMID 39488100 • 2024 Dec
Prebiotic inulin alleviates anxiety and depression-like behavior in alcohol withdrawal mice by modulating the gut microbiota and 5-HT metabolism.
Phytomedicine
Open PubMedPMID 15068828 • 2004 Apr 15
Safety of 5-hydroxy-L-tryptophan.
Toxicol Lett
Open PubMedPMID 40367689 • 2025 Jun 17
Promotion of sleep by cinnamic acid in parachlorophenylalanine-induced insomnia in rats.
Int Immunopharmacol
Open PubMedBenefit reports: 5
Adverse reports: 5
No-effect reports: 0
Mixed reports: 3
Unclear reports: 0
Signal confidence: 0.49
Benefits
Adverse
No Effect
Insufficient empirical signal for a directional adjustment.
Reddit evidence: 9 mentions (confidence 0.49) across Supplements, Biohackers, HubermanLab.
Amazon signal: 0 products scanned (confidence 0.00).
GNC signal: 0 products scanned (confidence 0.00) [ERROR].
terminated
Use adverse/interactions PubMed signal counts for screening; perform clinician review before high-dose or multi-drug stack use.
Human-study daily dose signal: 100 mg/day (confidence LOW).
Extracted from 1 dosing mentions across 1 PubMed studies (mg/day).
post • r/Supplements • mixed
5 htp is dangerous supplement I used it for 6 months and after quitting I think my brain is preminantly different. I hope I feel like normal person soon. The side effects I have: Poor verbal memory Don't understand what I feeling Inability…
Open mentionpost • r/Supplements • adverse
For those who’ve used 5-HTP, did you notice benefits or side effects? It is such an interesting product. Did you try it and had effects? And what was the product with what dose and what ingredients?
Open mentionpost • r/Supplements • benefit
What’s the purpose of such a low dose of 5-HTP added to these melatonin supplements? I only take half a supplement before bed, and it gives me the best sleep EVER. I’ve even given them to friends/family and they all agree these are hands d…
Open mentionpost • r/Supplements • unclear
5-HTP Dosage So i\`ve been taking 5-HTP for about 4-5 days now, ive been taking a pretty high dose, around 1000 mg - 2000 mg daily, and i was wondering if that is dangerous or if it is alright, like could it give Serotonin syndrome just 5-…
Open mentionpost • r/Supplements • benefit
I Tried 15+ Supplements for Better Sleep & Recovery - Here's What Actually Moved the Needle Hey r/supplements, wanted to share my experience after spending way too much money experimenting with sleep and recovery supplements over the past …
Open mentionpost • r/Biohackers • adverse
Anxiety Any tips to help reduce anxiety? I (40F) got everything controlled for over a year and recently it came back in full swing. I feel like I can feel the cortisol going through my system and I could cry on a dime, which is very unlike…
Open mentionpost • r/HubermanLab • mixed
What sleep supplements do you take? I have insomnia and started facing mood swings, hair loss, irritability, isolation and low motivation for past 8 months. I sleep 10 hours and would wake up often. I am now taking ashwagandha 650 mg, l th…
Open mentionpost • r/Supplements • mixed
My supplement stack is getting out of control. I need help trimming down my crazy... Hey friends - I'm dealing with a lot of personal/life issues and my supplement protocol is a reflection of it. But it's getting embarrassing at this point…
Open mentioncomment • r/Supplements • unclear
A lot of people don't get any acute effects from 5-HTP, necessitating chronic use (much like prescription SSRIs can take up to 6 weeks of daily administration to fully "land").
Open mentioncomment • r/Supplements • unclear
Probably depleted a lot of your B vitamins and magnesium considering those are cofactors. Were you taking it everyday? Since it directly converts to serotonin you really ought to cycle this a few days on and off. Please be careful going fo…
Open mentionamazon
Amazon search for 5-htp
Rating: n/a | Reviews: n/a
Open productEvidence Sources
Community Sources
PUBMED • Humans + preclinical triage
Counts aggregated from automated literature sweep and tiering rules.
Outcome: Tier HIGH; humans 51, RCTs 14, meta-analyses 0.[1582,1652,2116, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 34737364 from Sci Rep.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 38309227 from Clin Nutr.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 40944161 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 35583055 from J Diet Suppl.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 1998 • Human evidence curation set
PMID 9705024 from Int J Obes Relat Metab Disord.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2012 • Human evidence curation set
PMID 22684569 from J Huazhong Univ Sci Technolog Med Sci.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2020 • Human evidence curation set
PMID 33375373 from Int J Mol Sci.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2006 • Human evidence curation set
PMID 16023217 from Pharmacol Ther.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 39488100 from Phytomedicine.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2004 • Human evidence curation set
PMID 15068828 from Toxicol Lett.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 40367689 from Int Immunopharmacol.
Outcome: See linked PubMed abstract for methods and outcomes.[1582,1652,2116, etc.]
Open source