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Head-to-head evidence comparison — which supplement is right for you?
Vitamin B12 wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Mostly mechanism / observational
0 of 2 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
12 of 17 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both SAMe and Vitamin B12 have evidence — compare verdict strength side-by-side.
400-1600mg for mood; 600-1200mg for joints
On empty stomach, Morning and/or midday
Enteric-coated tablets (SAMe tosylate or butanedisulfonate)
500-1000mcg daily for maintenance; higher for deficiency
Morning (may be energizing), With or without food
Methylcobalamin (sublingual)
2-6 weeks
4-8 weeks
4-8 weeks
2-4 weeks
4-8 weeks
Weeks to months
S-Adenosylmethionine for osteoarthritis of the knee or hip
The Cochrane database of systematic reviews (2009) · Meta analysis · n=656
For pain, the analysis indicated a small SMD of -0.17 (95% CI -0.34 to 0.01), corresponding to a difference in pain scores between SAMe and placebo of 0.4 cm on a 10 cm VAS, with no between trial heterogeneity (I(2) = 0).
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).
S-Adenosylmethionine (SAMe) for Liver Health: A Systematic Review
Nutrients (2024) · Systematic review · n=15
The most common doses were SAMe 1000 mg or 1200 mg per day with or without another treatment or natural supplement.
Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta-analysis
Irish journal of medical science (2024) · Meta analysis · n=4275
Regarding the hemoglobin level, the pooled effect sizes showed no difference between all routes of administration that could reach statistical significance.
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.
Vitamin Status in Patients with Phenylketonuria: A Systematic Review and Meta-Analysis
International journal of molecular sciences (2024) · Meta analysis · n=770
The effect sizes were expressed as standardised mean differences.
Meta-analysis of 656 patients showed small effect size (SMD -0.17) corresponding to only 0.4cm improvement on 10cm pain scale. Effect is modest and barely reaches statistical significance threshold.
AI-estimated from published studies. Interpret as directional guidance.
Vitamin B12 has a higher evidence score (9/10 vs 9/10) and wins in 1 of 3 categories.
For support mood, SAMe has a higher relevance score (90 vs 55).
No known interactions between SAMe and Vitamin B12 have been documented in our database. However, always consult a healthcare provider before combining supplements.