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Head-to-head evidence comparison — which supplement is right for you?
B-Complex wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Probably helps
5 of 8 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
4 of 6 studies with measurable effects showed benefit.
Top outcomes
1 capsule daily (per label)
Morning with breakfast
Methylated B-complex (methylcobalamin, methylfolate)
200-600mg daily
Morning on empty stomach, Before stressful events
Standardized to 3% rosavins and 1% salidroside
2-4 weeks
4-8 weeks
Immediate
1 week
1-2 weeks
1 week
First dose
Dosage exploration of combined B-vitamin supplementation in stroke prevention: a meta-analysis and systematic review
The American journal of clinical nutrition (2024) · Meta analysis · n=76664
In areas without and with partial folic acid fortification, combined B-vitamin supplementation significantly reduced the risk of stroke by 34% [RR: 0.66; 95% confidence interval (CI): 0.50, 0.86] and 11% (RR: 0.89; 95% CI: 0.79, 1.00), respectively.
A Comparative Study Evaluating the Effectiveness of Folate-Based B Vitamin Intervention on Cognitive Function of Older Adults under Mandatory Folic Acid Fortification Policy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Nutrients (2024) · Meta analysis · n=42768
The meta-analysis on the effects of folate-based B vitamin supplementation on cognitive function showed a significant overall impact (Z = 3.84; p = 0.0001; SMD, 0.18; 95% CI, 0.09, 0.28).
A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and 'At-Risk' Individuals
Nutrients (2019) · Meta analysis · n=2015
Regarding individual facets of mood, B vitamin supplementation benefited stress (n = 958, SMD = 0.23, 95% CI = 0.02, 0.45, p = 0.03).
Efficacy of Pharmacological Interventions in Milder Depression: A Systematic Review and Meta-Analysis
Neuropsychopharmacology reports (2025) · Meta analysis · n=1049
A meta-analysis found no significant difference in response rates between the two treatments (risk ratio [RR] = 0.96, 95% CI: 0.78-1.18) or dropout rates (RR = 1.08, 95% CI: 0.62-1.88).
Rhodiola rosea supplementation on sports performance: A systematic review of randomized controlled trials
Phytotherapy research : PTR (2023) · Systematic review · n=263
Acute supplementation with RR has a positive effect on endurance performance and rating of perceived exertion (RPE).
Modulation of the hypothalamic-pituitary-adrenal (HPA) axis by plants and phytonutrients: a systematic review of human trials
Nutritional neuroscience (2022) · Systematic review
For most phytonutrients, the effects of supplementation on HPA-axis activity in humans is unclear.
Multiple meta-analyses show small but statistically significant benefits for cognitive function in older adults and stroke prevention populations. Effect sizes are modest (SMD ~0.15-0.18). Benefits may be more pronounced in B-vitamin deficient populations.
Based on systematic reviews showing anti-fatigue effects. Most studies used standardized extracts (3% rosavins/1% salidroside). Effects observed for both mental and physical fatigue.
AI-estimated from published studies. Interpret as directional guidance.
B-Complex has a higher evidence score (9/10 vs 8.5/10) and wins in 1 of 3 categories.
For boost daily energy, Rhodiola Rosea has a higher relevance score (85 vs 80).
No known interactions between B-Complex and Rhodiola Rosea have been documented in our database. However, always consult a healthcare provider before combining supplements.