Evidence Base

The studies behind every answer.

Original papers. Full analysis. Every finding linked to its DOI so you can check our work.

The Iron Math Your Supplement Label Doesn't Show Twenty-three studies, one dose threshold, and a math problem that changes what "100% Daily Value" actually means for anyone who trains. M et al. · 2024 · Journal of Sport and Health Science · n=669

The 0-for-6 Scorecard Your Supplement Aisle Hides Researchers tested your multivitamin across six body systems — cancer, heart, immunity, brain, eyes, and mortality. The score was not what the label promised. Wang et al. · 2025 · Ageing Research Reviews · n=5,535,426

The man who owned the patent funded the only study that said ZMA works A 33.5% testosterone claim traces to one industry-funded study with 53% dropout. Two independent labs found zero. But athletes might actually need more zinc — just not from a branded tub. Te et al. · 2023 · Journal of Trace Elements in Medicine and Biology · n=38

Three Strength Tests Came Back Empty. The Fourth Had a Receptor. Researchers pooled ten trials of vitamin D in 354 athletes. Blood levels soared. Bench, jump, and grip didn't move. But quadriceps — loaded with vitamin D receptors on their fast-twitch fibers — broke the pattern. Han et al. · 2024 · Frontiers in Nutrition · n=354

Fell Asleep Faster. Didn’t Sleep Longer. A meta-analysis pooled every trial on magnesium and sleep. One outcome improved. The other didn’t. The evidence base is thinner than the marketing suggests. Mah et al. · 2021 · BMC Complementary Medicine and Therapies · n=151

Every Study Said Yes. Then Came the Asterisks. A systematic review filtered 1,254 papers on magnesium and soreness down to four. Every survivor found magnesium helped. But the protocol everyone recommends was never actually tested, and the evidence rests on 73 people. Tarsitano et al. · 2024 · Journal of Translational Medicine · n=73

Studies

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