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Head-to-head evidence comparison — which supplement is right for you?
Riboflavin wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
6 of 6 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
8 of 10 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Glycine and Riboflavin have evidence — compare verdict strength side-by-side.
3g before bed
30-60 minutes before bed
Powder (dissolves easily, tastes sweet)
25-50mg for general health; 400mg for migraine prevention
With food for better absorption, Morning with other B vitamins
Riboflavin or Riboflavin-5-Phosphate (R-5-P)
First few nights
Next morning
Immediate
3 months
2-4 weeks
Immediate
The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review
GeroScience (2024) · Systematic review · n=34
The nervous system demonstrated the most positive effects, including improved psychiatric symptoms from longer-term glycine administration in psychiatric populations.
Glutamatergic drugs for schizophrenia
The Cochrane database of systematic reviews (2006) · Meta analysis · n=132
NMDA receptor co-agonists glycine and D-serine showed some effects in reducing the negative symptoms of schizophrenia (n=132, SMD -0.66, CI -1.0 to -0.3, p=0.0004), but the magnitude of the effect was moderate.
Ingestion of a Whey Plus Collagen Protein Blend Increases Myofibrillar and Muscle Connective Protein Synthesis Rates
Medicine and science in sports and exercise (2025) · Rct · n=14
In addition, myofibrillar protein synthesis rates were higher in BLEND compared with PLA in both the rested (0.038 ± 0.008 and 0.031 ± 0.006%·h -1 , respectively; P < 0.05) and exercised (0.052 ± 0.011 and 0.039 ± 0.009%·h -1 , respectively; P < 0.01) leg.
Effect of Vitamin B2 supplementation on migraine prophylaxis: a systematic review and meta-analysis
Nutritional neuroscience (2022) · Meta analysis · n=673
Vitamin B2 supplementation significantly decreased migraine days (p = .005, I2 = 89%), duration (p = .003, I2 = 0), frequency (p = .001, I2 = 65%), and pain score (p = .015, I2 = 84%).
Effects of selected dietary supplements on migraine prophylaxis: A systematic review and dose-response meta-analysis of randomized controlled trials
Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology (2025) · Meta analysis
In adults, compared with placebo, these supplements did not significantly affect other outcomes, and omega-3 supplementation did not yield a statistically significant reduction in any of these outcomes.
Riboflavin supplements for blood pressure lowering in adults
The Cochrane database of systematic reviews (2025) · Meta analysis · n=320
The evidence for the effect of oral riboflavin supplements on systolic and diastolic blood pressure is very uncertain.
Based on systematic review showing nervous system benefits. Limited specific RCT data for sleep outcomes. Effects may vary significantly between individuals.
Based on meta-analysis showing significant reduction in migraine frequency, days, duration, and pain score. High heterogeneity (I2=65-89%) in pooled analyses suggests variable individual responses. Most studies used 400mg daily dose.
AI-estimated from published studies. Interpret as directional guidance.
Riboflavin has a higher evidence score (6.5/10 vs 6.5/10) and wins in 1 of 3 categories.
For prenatal support, Riboflavin has a higher relevance score (78 vs 70).
No known interactions between Glycine and Riboflavin have been documented in our database. However, always consult a healthcare provider before combining supplements.