Supplement
Supports broad cellular function with category-specific mechanisms.[2926,3141,3813, etc.]
Superscript reference numbers link to the Sources bibliography.
Composite Rating
Blends evidence depth, community direction, safety friction, and completeness.
Evidence Intensity
100/100
High depth from human/RCT/meta counts
Community Direction
21
Positive Lean • confidence Moderate
Safety Friction
100/100
High signal from adverse/interaction markers
Data Completeness
100%
Studies 12 • mentions 10 • links 23
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.[31,96,289, etc.]
Dose guide: Human-study daily dose: 15 mg-40 mg/day (higher-confidence extraction from PubMed abstracts)..[31,96,289, etc.]
Category
Other
Evidence Tier
HIGH
Daily Guide
Human-study daily dose: 15 mg-40 mg/day (higher-confidence extraction from PubMed abstracts).
Clinical Depth
Humans: 206 • RCTs: 14 • Meta: 0
Cohort / Real-World
Cohort signals: 0
Safety Markers
Adverse signals: 490 • Interactions: 1,010
Freshness, trend, and study timeline for this item
Status
Trend
→ Stable evidence base
Depth
629 total studies · 3 recent
Timeline
Animal-only studies
4,607
In vitro / tissue
1,672
Interaction signals
1,010
Total indexed
629
Safety adverse signals
490
Human studies
206
Weighted direction score: 21 (Positive Lean)
High when >=2 human meta-analyses, or >=5 human RCTs with substantial human literature volume.
Animal-only studies
4,607
In vitro / tissue
1,672
Interaction signals
1,010
Total indexed
629
Safety adverse signals
490
Human studies
206
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 35616942 • 2022 May 2
Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline: A Randomized Clinical Trial.
JAMA Netw Open
Open PubMedPMID 39405978 • 2024 Dec
Supplementation of spermidine at 40 mg/day has minimal effects on circulating polyamines: An exploratory double-blind randomized controlled trial in older men.
Nutr Res
Open PubMedPMID 39549554 • 2024 Dec
Absorption, anti-inflammatory, antioxidant, and cardioprotective impacts of a novel fasting mimetic containing spermidine, nicotinamide, palmitoylethanolamide, and oleoylethanolamide: A pilot dose-escalation study in healthy young adult men.
Nutr Res
Open PubMedPMID 37111071 • 2023 Apr 12
High-Dose Spermidine Supplementation Does Not Increase Spermidine Levels in Blood Plasma and Saliva of Healthy Adults: A Randomized Placebo-Controlled Pharmacokinetic and Metabolomic Study.
Nutrients
Open PubMedPMID 30388439 • 2018 Dec
The effect of spermidine on memory performance in older adults at risk for dementia: A randomized controlled trial.
Cortex
Open PubMedPMID 33211152 • 2021 May
The positive effect of spermidine in older adults suffering from dementia : First results of a 3-month trial.
Wien Klin Wochenschr
Open PubMedPMID 29371440 • 2018 Jan 26
Spermidine in health and disease.
Science
Open PubMedPMID 37845508 • 2023 Nov
Polyamine metabolite spermidine rejuvenates oocyte quality by enhancing mitophagy during female reproductive aging.
Nat Aging
Open PubMedPMID 33151120 • 2020 Nov 9
Spermidine improves gut barrier integrity and gut microbiota function in diet-induced obese mice.
Gut Microbes
Open PubMedPMID 33852843 • 2021 Apr 13
Dietary spermidine improves cognitive function.
Cell Rep
Open PubMedPMID 34105442 • 2021 Aug
Spermidine-induced hypusination preserves mitochondrial and cognitive function during aging.
Autophagy
Open PubMedPMID 37723019 • 2024 May
Spermidine - an old molecule with a new age-defying immune function.
Trends Cell Biol
Open PubMedBenefit reports: 5
Adverse reports: 2
No-effect reports: 0
Mixed reports: 3
Unclear reports: 0
Signal confidence: 0.41
Benefits
Adverse
No Effect
Insufficient empirical signal for a directional adjustment.
Reddit evidence: 7 mentions (confidence 0.41) across Biohackers, Supplements.
Amazon signal: 0 products scanned (confidence 0.00).
GNC signal: 0 products scanned (confidence 0.00) [BLOCKED].
PerimeterX / captcha block encountered.
Use adverse/interactions PubMed signal counts for screening; perform clinician review before high-dose or multi-drug stack use.
Human-study daily dose signal: 15 mg-40 mg/day (confidence HIGH).
Extracted from 7 dosing mentions across 3 PubMed studies (mg/day).
Imported legacy community score: 8.0/10 (heuristic mapping confidence 1.00).
Imported legacy monthly cost signal: ~$30.00.
Legacy community note: Growing rapidly in longevity community. Users appreciate the fasting-mimicking autophagy benefit without actually fasting. Wheat germ extract is the most common delivery form. Often part of advanced longevity stacks.
Sentiment Score
-0.08081999999999998/100
Benefit Mentions
Adverse Mentions
Best Responders
No responder profile recorded.
post • r/Biohackers • unclear
Distinct Roles of Urolithin A and Spermidine in Mitophagy and Autophagy: Implications for Dietary Supplementation | Nutrition Research Reviews (2025)
Open mentionpost • r/Supplements • mixed
Confused about spermidine: side effects and dosage For those who don't know, spermidine is a longevity supplement that increases autophagy. TL;DR: Spermidine seems to give me nausea and increase my saliva production AND give me a lot of en…
Open mentionpost • r/Biohackers • benefit
A study tracked 146 nutrients in 829 people across 15 years to see their effects on mortality and longevity. Guess which nutrient out of those 146 was easily ranked as the most beneficial? **Spermidine!** In a study of 146 nutrients, sperm…
Open mentionpost • r/Supplements • mixed
What Are the Best Anti Aging Supplements to Take in Your 30s for Long-Term Health? hey i’m in my 30s and been getting more into anti aging stuff lately. i already eat decent, stay active, try to sleep enough but i figured why not start doi…
Open mentionpost • r/Biohackers • unclear
What are your top longevity supplements in 2025? I'm trying to build a solid longevity stack and would love to hear from people who are already experimenting with supplements for healthy aging. What are your top picks right now? Think NMN,…
Open mentionpost • r/Supplements • unclear
Bryan Johnson's Supplement Lis # Bryan Johnson's Supplement List I just finished a writeup on Bryan Johnson's Supplement stack and figured I would share here for anyone interested. [**This full list with more information**](https://jakesjo…
Open mentionpost • r/Biohackers • unclear
22M: My Personalized Longevity Stack for Health, Hormonal Balance & Vascular Function Hi friends, I’m a 22 year old who has been experimenting with a structured longevity stack. My goals are not only healthy aging but also hormonal balance…
Open mentionpost • r/Biohackers • benefit
Longevity protocol - Thoughts ? Greetings all Long time lurker- first time posting. Been working on my Vitagenix longevity protocol for the past 5 years experimenting, optimizing and updating when needed. I'd like some push back though it …
Open mentioncomment • r/Biohackers • benefit
# Abstract The increasing focus on longevity and cellular health has brought into the spotlight two key compounds, urolithin A (UroA) and spermidine, for their promising roles in autophagy and mitophagy. Urolithin A, a natural metabolite d…
Open mentioncomment • r/Supplements • mixed
Spermidine’s mostly marketed for its possible “cell cleanup” effects, but in practice people usually stick to much smaller amounts than 10 mg/day—more like 1–6 mg from wheat-germ extracts. Some have more energy or appetite changes, but nau…
Open mentionamazon
Amazon search for Spermidine
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 206, RCTs 14, meta-analyses 0.[2926,3141,3813, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 35616942 from JAMA Netw Open.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 39405978 from Nutr Res.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 39549554 from Nutr Res.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 37111071 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2018 • Human evidence curation set
PMID 30388439 from Cortex.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 33211152 from Wien Klin Wochenschr.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2018 • Human evidence curation set
PMID 29371440 from Science.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 37845508 from Nat Aging.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2020 • Human evidence curation set
PMID 33151120 from Gut Microbes.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 33852843 from Cell Rep.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 34105442 from Autophagy.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 37723019 from Trends Cell Biol.
Outcome: See linked PubMed abstract for methods and outcomes.[2926,3141,3813, etc.]
Open source