Superhuman Blend
Published research and evidence base
The published literature relates to the individual amino acids commonly used in performance blends - glycine, glutamine, arginine, citrulline and citrulline malate, the branched-chain amino acids leucine, isoleucine and valine, beta-alanine, taurine, L-carnitine and essential amino acid mixtures - rather than to any branded combination as formulated. Human randomised trials and meta-analyses dominate this evidence base, with endpoints spanning muscle protein synthesis, high-intensity and endurance exercise performance, markers of exercise-induced muscle damage, vascular and nitric oxide-related outcomes, and fatigue. Effect sizes are generally small and heterogeneous, and several recent meta-analyses report null or very low-certainty findings for specific endpoints. No study identified evaluated the constituents together as a single fixed-ratio blend.
- Studies cited
- 15
- Published 2023+
- 10
- Newest paper
- 2026
- Last reviewed
- Aug 2026
Recurring themes in the literature
- muscle protein synthesis
- high-intensity exercise performance and buffering capacity
- exercise-induced muscle damage and recovery
- nitric oxide, endothelial function and blood flow
- fatigue and time to exhaustion
- sarcopenia and older-adult physical function
- oxidative stress and mitochondrial function
15 published studies.
Ordered by strength of study design, then by recency. Every entry links to its source record so the finding can be checked against the paper rather than taken on our word.
- 01Systematic review2026
Effects of Citrulline Malate Supplementation on Exercise Performance: A Systematic Review and Three-Level Meta-Analysis
Wang X, et al. · Nutrients · three-level meta-analysis of 30 randomised controlled trials, 138 effect sizes, 644 participants
Citrulline malate produced a small overall improvement in exercise performance relative to placebo, with the effect more apparent for acute than chronic dosing. The authors rated certainty of the evidence as limited and noted unresolved questions on dose and target population.
- 02Systematic review2026
Effects of beta-alanine supplementation on exercise performance and related physiological outcomes in women: a systematic review and meta-analysis
Gu J, et al. · Frontiers in Nutrition · meta-analysis of 12 reports from 11 independent randomised controlled trials, 312 women
Beta-alanine supplementation improved time to exhaustion in women, while estimates for peak power and anaerobic performance were imprecise. Overall certainty of evidence was rated very low.
- 03Systematic review2026
No ergogenic effect of β-alanine on repeated sprint ability: a systematic review and multilevel meta-analysis of randomized controlled trials
Liang W, et al. · Frontiers in Nutrition · multilevel meta-analysis of 17 randomised controlled trials
Chronic beta-alanine supplementation did not significantly improve repeated sprint ability on any pooled outcome measure. The review concerned beta-alanine alone.
- 04Systematic review2025
The Effect of Oral Pure Branched-Chain Amino Acid Supplementation on Exercise Performance and Body Composition: A Systematic Review
Julea M, et al. · Cureus · systematic review of 22 randomised controlled trials, 511 healthy adults
Pure branched-chain amino acid (leucine, isoleucine, valine) supplementation showed moderate support for reduced post-exercise muscle soreness, but evidence for strength, endurance and body composition effects was inconsistent.
- 05Systematic review2025
Does One Shot Work? The Acute Impact of a Single Taurine Dose on Exercise Performance: A Meta-Analytic Review
Deng H, et al. · Scandinavian Journal of Medicine & Science in Sports · meta-analysis of 23 randomised trials, 69 comparisons
Acute taurine ingestion produced small-to-moderate improvements in exercise performance, with larger estimates in male participants and aerobic tasks. Certainty of evidence was low to very low.
- 06Systematic review2024
Nutritional interventions for exercise-induced muscle damage: an umbrella review of systematic reviews and meta-analyses of randomized trials
Talebi S, et al. · Nutrition Reviews · umbrella review of 53 meta-analyses covering 24 nutritional interventions
Among the interventions assessed, L-carnitine and branched-chain amino acids were among those associated with reduced markers of exercise-induced muscle damage at moderate certainty of evidence.
- 07Systematic review2023
Effects of Whey Protein, Leucine, and Vitamin D Supplementation in Patients with Sarcopenia: A Systematic Review and Meta-Analysis
Chang MC, et al. · Nutrients · meta-analysis of three randomised controlled trials, 637 patients with sarcopenia
Supplementation combining whey protein, leucine and vitamin D increased appendicular muscle mass, with additional strength and function gains when paired with exercise. Leucine was not isolated from the other components.
- 08Systematic review2021
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
d'Unienville NMA, et al. · Journal of the International Society of Sports Nutrition · systematic review and meta-analysis of 118 randomised controlled trials
Pooled analyses of nitrate, polyphenol, L-arginine and L-citrulline sources found trivial though statistically significant benefits for endurance performance, with effects varying by food source and participant sex.
- 09Systematic review2020
The Effect of L-Carnitine Supplementation on Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis of Randomized Clinical Trials
Yarizadh H, et al. · Journal of the American College of Nutrition · meta-analysis of seven randomised clinical trials
L-carnitine supplementation was associated with significant reductions in muscle soreness across several post-exercise timepoints and lower muscle damage markers at 24 hours.
- 10Human clinical2026
Short-term citrulline malate supplementation enhances lower-limb function in physically active older women
Ramos-Hernández R, et al. · Clinical Nutrition ESPEN · six-week randomised controlled pilot trial, 3 g/day citrulline malate plus multicomponent exercise training in physically active older women
Citrulline malate combined with multicomponent training significantly improved sit-to-stand performance versus the control condition, with favourable but non-significant trends for walking endurance. The trial concerned citrulline malate.
- 11Human clinical2023
Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial
Kumar P, et al. · The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences · 16-week randomised placebo-controlled trial in 24 older adults
Glycine combined with N-acetylcysteine corrected glutathione deficiency and improved oxidative stress, mitochondrial function, inflammation and measures of physical function relative to placebo. The glycine effect cannot be separated from the co-administered N-acetylcysteine.
- 12Human clinical2009
Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men
Moore DR, et al. · The American Journal of Clinical Nutrition · randomised crossover dose-response trial, six healthy young men, 0-40 g egg protein after resistance exercise
Myofibrillar protein synthesis was maximally stimulated by approximately 20 g of ingested protein after resistance exercise, with no further increase at 40 g. This foundational trial underpins the essential amino acid and leucine dose-threshold literature.
- 13Review2026
Glutamine Supplementation and Exercise: A Narrative Review of Biochemical Mechanisms and Timing Strategies
Djordjevic B, et al. · Medicina (Kaunas) · narrative review of glutamine mechanisms and supplementation timing in exercise contexts
The review described glutamine's roles in protein turnover, redox balance and immune function, but reported that clinical outcomes from glutamine supplementation in exercising populations remain inconsistent and that optimal timing is unresolved.
- 14Review2017
International Society of Sports Nutrition Position Stand: protein and exercise
Jäger R, et al. · Journal of the International Society of Sports Nutrition · position stand; narrative synthesis of protein and amino acid intake in exercising populations
The position stand concluded that daily protein intakes of approximately 1.4-2.0 g/kg body mass support muscle protein synthesis and training adaptation, and addressed the essential amino acid and leucine content required to maximally stimulate synthesis per feeding.
- 15Review2015
International society of sports nutrition position stand: Beta-Alanine
Trexler ET, et al. · Journal of the International Society of Sports Nutrition · position stand; narrative synthesis of the beta-alanine literature
The position stand concluded that 4-6 g/day of beta-alanine for two to four weeks raises muscle carnosine and improves exercise performance in efforts lasting roughly one to four minutes, with paraesthesia the main reported side effect.
What this evidence does not establish.
No published trial has evaluated these amino acids together in a single fixed-ratio blend, so any additive or synergistic effect of the combination is untested. Individual constituents also differ widely in evidence quality: several 2026 meta-analyses report null or very-low-certainty findings for beta-alanine and citrulline malate on specific endpoints, glutamine outcomes in exercising populations remain inconsistent, and glycine's ergogenic effects have generally been studied only alongside N-acetylcysteine rather than in isolation.
Common questions about the research.
- What does the literature say about the arginine and citrulline components?
Arginine is the direct substrate for nitric oxide synthase. Clinical pharmacology reviews describe citrulline as raising plasma arginine more efficiently than arginine itself, because it escapes hepatic first-pass metabolism and intestinal arginase before being converted back to arginine in the kidney. Exercise-science reviews of citrulline report mixed findings across performance protocols.
- Why are taurine and carnitine included?
Both are studied in muscle and mitochondrial contexts. Taurine is among the most abundant free amino acids in skeletal muscle and heart, and the experimental literature associates it with membrane stabilisation, osmoregulation, and vascular tone. L-carnitine is the carrier that transports long-chain fatty acids into the mitochondrial matrix for beta-oxidation, and has been examined in exercise-recovery studies.
- What role does N-acetylcysteine play?
NAC acts as a cysteine donor for glutathione synthesis. Controlled exercise studies have used it to raise muscle cysteine and glutathione availability while examining how redox status relates to skeletal-muscle fatigue, which makes it a common inclusion in research formulations of this kind.
- Has this specific combination been studied?
No. The cited literature examines the individual components — citrulline and arginine, taurine, carnitine, and N-acetylcysteine — in separate protocols. No published study characterises this nine-component mixture as a whole, and findings for a single component should not be read across to the blend.
Available from our catalog
For research purposes only. Not for human consumption, diagnosis, treatment, or prevention of any condition. Nothing on this page is medical advice, and no study summarised here should be read as a recommendation.