We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more
Head-to-head evidence comparison — which supplement is right for you?
L-Glutamine wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
3 of 3 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
12 of 13 studies with measurable effects showed benefit.
Top outcomes
5-10g
Post-workout, Before bed, Or split throughout day
L-Glutamine powder
10mg lutein + 2mg zeaxanthin
With a meal containing fat
Softgels with both lutein and zeaxanthin
2-4 weeks
2-4 weeks
1-2 weeks
3-6 months
4-8 weeks
3-6 months
A Phase 3 Trial of l-Glutamine in Sickle Cell Disease
The New England journal of medicine (2018) · Rct · n=230
A total of 230 patients (age range, 5 to 58 years; 53.9% female) were randomly assigned, in a 2:1 ratio, to receive l-glutamine (152 patients) or placebo (78 patients).
What Is the Role of Nutritional Supplements in Support of Total Hip Replacement and Total Knee Replacement Surgeries? A Systematic Review
Nutrients (2018) · Systematic review
Amino acid supplementation is reported to reduce muscle atrophy and accelerate return of functional mobility.
Evidence and gaps in clinical outcomes of novel pharmacologic therapies for sickle cell disease: A systematic literature review highlighting insights from clinical trials and real-world studies
Blood reviews (2025) · Systematic review · n=97
A pivotal phase III study of l-glutamine showed that patients treated with l-glutamine had a 25 % reduction in pain crises and 33 % fewer hospital days compared to placebo. l-glutamine was generally well tolerated with minimal side effects.
The effects of lutein on cardiometabolic health across the life course: a systematic review and meta-analysis
The American journal of clinical nutrition (2016) · Meta analysis · n=387569
Meta-analysis showed a lower risk of coronary heart disease (pooled RR: 0.88; 95% CI: 0.80, 0.98) and stroke (pooled RR: 0.82; 95% CI: 0.72, 0.93) for the highest compared with the lowest tertile of lutein blood concentration or intake.
Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration
The Cochrane database of systematic reviews (2023) · Systematic review · n=2445
These studies enroled 11,952 people aged 65 to 75 years and included slightly more women (on average 56% women).
Long-term Outcomes of Adding Lutein/Zeaxanthin and ω-3 Fatty Acids to the AREDS Supplements on Age-Related Macular Degeneration Progression: AREDS2 Report 28
JAMA ophthalmology (2022) · Rct · n=3882
This study included 3882 participants (mean [SD] baseline age, 72.0 [7.7] years; 2240 women [57.7%]) and 6351 eyes.
Based on RCT showing reduced URTI incidence in combat athletes (n=21) and enhanced IgA levels. Limited sample size and specific population studied. Effect may be primarily in high-stress/training conditions.
Based on multiple meta-analyses showing significant MPOD increases in both AMD patients and healthy subjects. Effect size modest but consistent across studies. Higher doses may increase carotenodermia risk.
AI-estimated from published studies. Interpret as directional guidance.
L-Glutamine has a higher evidence score (9/10 vs 9/10) and wins in 1 of 3 categories.
No known interactions between L-Glutamine and Lutein + Zeaxanthin have been documented in our database. However, always consult a healthcare provider before combining supplements.