47 human trials, including the one that found nothing.

At 200 mg over 4 weeks, the study measured stress-related symptom scores, sleep quality, and verbal fluency.

A meta-analysis showing faster visual processing and recognition (a narrow, specific cognitive benefit).

A meta-analysis of 897 participants that measured better subjective sleep-quality scores and lower daytime-dysfunction ratings.

Over 28 days, the study measured lower perceived-stress scores in adults with moderate stress.

A single 200 mg dose was associated with a lower cortisol response and more alpha-wave activity within an hour in the study.

A systematic review concluding 200 to 400 mg per day may support a healthy stress response in stress-exposed people.

An fMRI companion study showing sharper target-specific attention and less mind-wandering.

At 200 mg, improved recognition and attention on a reaction-time task, with or without caffeine.

In the study, 200 mg was associated with lower self-rated stress within an hour and a different cortisol response within three hours.

At 200 mg, reduced tension and supported a calmer response to an acute stressor in high responders.

Increased calm alpha-wave activity in the brain versus placebo.

At 200 mg, blunted the heart-rate and stress-marker response to an acute stressor.

At 200 mg, improved a self-rated tranquil-versus-troubled state at rest.

The foundational 200 mg study showing increased alpha-wave generation, most pronounced in people prone to everyday tension.

A large trial that measured stress, vigor, and cognitive-performance scores under mental load with a high-dose B-complex.

Over 12 weeks, the study measured lower prolonged stress reactivity and better mood scores.

Used the same active coenzyme forms we do (P-5-P and methylcobalamin) in a genotype-tailored trial.

The study measured greater physical endurance and lower fatigue markers, consistent with the energy-metabolism role.

A meta-analysis reporting lower measured perceived-stress scores with B vitamins in healthy and at-risk adults.

Raised B-vitamin status and linked it to brain-energy metabolism over 6 months.

We show this too: across 27,882 people, B vitamins had little or no effect on general cognition.

A meta-analysis that measured lower stress and fatigue scores with vitamin-and-mineral supplementation.

Over 12 weeks, the study measured lower personal-strain and work-related-stress scores.