Moderate evidenceStress & mood

Stress B-Complex

High-dose B vitamin complexes aimed at perceived stress. Meta-analysis supports a small reduction in stress scores in healthy adults; the effect on clinical depression or anxiety is not established.

Evidence last reviewed: August 2026

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What the science says

Perceived stress in healthy adults Moderate evidence
A systematic review and meta-analysis of 18 randomized controlled trials found that B vitamin supplementation reduced perceived stress in healthy and at-risk populations, with a small but statistically reliable effect. There was no clear benefit for depressive or anxiety symptoms.
Workplace stress Moderate evidence
A 90-day randomized, placebo-controlled trial in 60 working adults found that a high-dose B-complex lowered work-related stress and depressed mood scores. The sample was small and the outcome was self-reported.
Acute mood and mental performance Limited evidence
A randomized placebo-controlled trial in 215 healthy men found that a high-dose B-complex with vitamin C and minerals improved ratings of vigour and reduced mental fatigue during demanding tasks after 33 days. Effects on objective cognitive performance were minor.

Dosage & safety

Studied doseTrials used complexes supplying several times the daily reference intake of thiamine, riboflavin, B6, folate and B12 — typically one tablet daily with food. There is no benefit to megadoses beyond the amounts used in these products.

SafetyB vitamins are water-soluble and generally well tolerated; bright yellow urine from riboflavin is harmless. Chronic high-dose vitamin B6 (above roughly 100 mg/day, and reported at lower doses) can cause peripheral neuropathy, and some 'stress' formulas exceed that. High folic acid can mask B12 deficiency. Niacin at high doses causes flushing and can affect the liver.

Scientific references

A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and 'At-Risk' Individuals
Young LM, Pipingas A, White DJ — Nutrients, 2019
The effect of 90 day administration of a high dose vitamin B-complex on work stress
Stough C, Scholey A, Lloyd J — Hum Psychopharmacol, 2011
Effects of high-dose B vitamin complex with vitamin C and minerals on subjective mood and performance in healthy males
Kennedy DO, Veasey R, Watson A — Psychopharmacology (Berl), 2010

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