Supplement
Arginine precursor to support nitric oxide bioavailability.[3115,3853,4015, 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
2
Mixed / Neutral • confidence Minimal
Safety Friction
100/100
High signal from adverse/interaction markers
Data Completeness
100%
Studies 15 • mentions 5 • links 25
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.
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Goal alignment: Performance, Heart Health.[538,686,910, etc.]
Dose guide: Human-study daily dose: 200 mg-6000 mg/day (higher-confidence extraction from PubMed abstracts)..[538,686,910, etc.]
Category
Amino Acid
Evidence Tier
HIGH
Daily Guide
Human-study daily dose: 200 mg-6000 mg/day (higher-confidence extraction from PubMed abstracts).
Clinical Depth
Humans: 188 • RCTs: 71 • Meta: 8
Cohort / Real-World
Cohort signals: 0
Safety Markers
Adverse signals: 56 • Interactions: 115
Freshness, trend, and study timeline for this item
Status
Trend
→ Stable evidence base
Depth
365 total studies · 5 recent
Timeline
Animal-only studies
776
Total indexed
365
In vitro / tissue
202
Human studies
188
Interaction signals
115
Randomized trials
71
Weighted direction score: 2 (Mixed / Neutral)
High when >=2 human meta-analyses, or >=5 human RCTs with substantial human literature volume.
Animal-only studies
776
Total indexed
365
In vitro / tissue
202
Human studies
188
Interaction signals
115
Randomized trials
71
Safety adverse signals
56
Meta-analyses
8
Distribution of evidence by study design strength
Evidence Strength: High
Composite of study volume, RCTs, and meta-analyses
PMID 34965876 • 2021 Dec 29
Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trials.
J Int Soc Sports Nutr
Open PubMedPMID 39800868 • 2025 May
L-Arginine and L-Citrulline for Prevention and Treatment of Pre-Eclampsia: A Systematic Review and Meta-Analysis.
BJOG
Open PubMedPMID 30284051 • 2018 Oct 3
Effect of L-Citrulline Supplementation on Blood Pressure: a Systematic Review and Meta-Analysis of Clinical Trials.
Curr Hypertens Rep
Open PubMedPMID 41097202 • 2025 Sep 30
Effects of Citrulline or Watermelon Supplementation on Body Composition: A Systematic Review and Dose-Response Meta-Analysis.
Nutrients
Open PubMedPMID 37111214 • 2023 Apr 21
Absence of Effects of L-Arginine and L-Citrulline on Inflammatory Biomarkers and Oxidative Stress in Response to Physical Exercise: A Systematic Review with Meta-Analysis.
Nutrients
Open PubMedPMID 33308806 • 2020 Dec
Effect of citrulline on post-exercise rating of perceived exertion, muscle soreness, and blood lactate levels: A systematic review and meta-analysis.
J Sport Health Sci
Open PubMedPMID 34579009 • 2021 Sep 8
L-Citrulline Supplementation and Exercise in the Management of Sarcopenia.
Nutrients
Open PubMedPMID 37242187 • 2023 May 14
The Effect of Acute Pre-Workout Supplement Ingestion on Basketball-Specific Performance of Well-Trained Athletes.
Nutrients
Open PubMedPMID 39638148 • 2025 Feb
Oral citrulline supplementation in pregnancies with preeclampsia: a multicenter, randomized, double-blind clinical trial.
Am J Clin Nutr
Open PubMedPMID 33876875 • 2021 Jun
The impact of L-citrulline supplementation on glucose homeostasis, lipid profile, and some inflammatory factors in overweight and obese patients with type 2 diabetes: A double-blind randomized placebo-controlled trial.
Phytother Res
Open PubMedPMID 39662304 • 2025 Mar 1
Malate or Not? Acute Effects of L-Citrulline Versus Citrulline Malate on Neuromuscular Performance in Young, Trained Adults: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial.
Int J Sport Nutr Exerc Metab
Open PubMedPMID 40010353 • 2025 Apr 1
Effects of Combined Versus Single Supplementation of Creatine, Beta-Alanine, and L-Citrulline During Short Sprint Interval Training on Basketball Players' Performance: A Double-Blind Randomized Placebo-Controlled Trial.
Int J Sports Physiol Perform
Open PubMedPMID 36480969 • 2022 Dec 13
Micronutrient Supplementation to Reduce Cardiovascular Risk.
J Am Coll Cardiol
Open PubMedPMID 36771366 • 2023 Jan 28
Supplementation with Nitric Oxide Precursors for Strength Performance: A Review of the Current Literature.
Nutrients
Open PubMedPMID 36904267 • 2023 Mar 3
Dietary Arginine and Citrulline Supplements for Cardiovascular Health and Athletic Performance: A Narrative Review.
Nutrients
Open PubMedBenefit reports: 2
Adverse reports: 1
No-effect reports: 1
Mixed reports: 1
Unclear reports: 0
Signal confidence: 0.00
Benefits
Adverse
No Effect
Popular in stimulant-free performance stacks. | Step2: Insufficient empirical signal for a directional adjustment.
Reddit evidence: 0 mentions (confidence 0.00).
Amazon signal: 0 products scanned (confidence 0.00).
GNC signal: 0 products scanned (confidence 0.00) [BLOCKED].
PerimeterX / captcha block encountered.
Search fetch failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=relevance&t=year&limit=12&q=%22l-citrulline%22%20(supplement%20OR%20dosage%20OR%20stack%20OR%20side%20effects%20OR%20review)%20(subreddit%3ASupplements%20OR%20subreddit%3ANootropics%20OR%20subreddit%3ABiohackers%20OR%20subreddit%3Alongevity%20OR%20subreddit%3ANutrition%20OR%20subreddit%3AHubermanLab%20OR%20subreddit%3ASleep%20OR%20subreddit%3AFitness%20OR%20subreddit%3Aketoscience%20OR%20subreddit%3AStackAdvice)
Fallback search failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=comments&t=all&limit=16&q=%22l-citrulline%22%20(supplement%20OR%20capsule%20OR%20powder%20OR%20experience%20OR%20results%20OR%20side%20effects)
Broad search failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=new&t=all&limit=16&q=l-citrulline
Use adverse/interactions PubMed signal counts for screening; perform clinician review before high-dose or multi-drug stack use.
Human-study daily dose signal: 200 mg-6000 mg/day (confidence HIGH).
Extracted from 10 dosing mentions across 3 PubMed studies (mg/day).
Imported legacy community score: 7.0/10 (heuristic mapping confidence 1.00).
Imported legacy monthly cost signal: ~$18.00.
Legacy community note: Well-respected for blood sugar and neuropathy. R-ALA form gaining preference over racemic ALA. ALCAR + ALA "mito stack" is popular in anti-aging community. Some users report skin improvements.
aggregate • benefit
Aggregate community signal: 5 directional mentions (benefit 2, adverse 1, no-effect 1, mixed 1).
Open mentionamazon
Amazon search for L-Citrulline
Rating: n/a | Reviews: n/a
Open productEvidence Sources
Community Sources
RCT • 2022 • Adults
Recreationally trained adults.
Outcome: May improve reps-to-failure and perceived exertion.[3115,3853,4015, etc.]
PUBMED • Humans + preclinical triage
Counts aggregated from automated literature sweep and tiering rules.
Outcome: Tier HIGH; humans 188, RCTs 71, meta-analyses 8.[3115,3853,4015, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 34965876 from J Int Soc Sports Nutr.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 39800868 from BJOG.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2018 • Human evidence curation set
PMID 30284051 from Curr Hypertens Rep.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 41097202 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 37111214 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2020 • Human evidence curation set
PMID 33308806 from J Sport Health Sci.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 34579009 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 37242187 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 39638148 from Am J Clin Nutr.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 33876875 from Phytother Res.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 39662304 from Int J Sport Nutr Exerc Metab.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 40010353 from Int J Sports Physiol Perform.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 36480969 from J Am Coll Cardiol.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 36771366 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 36904267 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[3115,3853,4015, etc.]
Open source