Supplements that actually work — graded by evidence, not influencer.

Most supplement studies fail to replicate. Different dose, different bioavailable form, wrong population, no baseline measurement, n of 24, conflict of interest. When a compound “shows promise” in one underpowered trial and nowhere else, that's not evidence — it's a hypothesis. We weight RCTs by quality, replication, and effect size, then say so plainly when the signal is preliminary.

A short list has actual human evidence. Creatine monohydrate (strength, cognition, dose 3–5 g/day). Omega-3 EPA/DHA (triglycerides, mood, 2–4 g/day combined). Vitamin D3 (correction of deficiency, 2,000–5,000 IU titrated to a 25(OH)D of 40–60 ng/mL). Magnesium glycinate (sleep onset, 200–400 mg). These are the foundation. Almost everything else is situational.

Test before you supplement. Vitamin D, ferritin, B12, magnesium RBC, omega-3 index, and TSH should be measured before stacking pills. Supplementing into a normal level rarely moves anything. Supplementing into a deficiency moves a lot. We link each entry to the biomarker page that tells you whether you actually need it.

Brand quality matters more than label claims. The US supplement industry is not pre-market regulated. Look for third-party certification: NSF Certified for Sport, USP Verified, Informed Sport, or COA-verified labs. Heavy metals, fillers, and under-dosing are common. We name brands that consistently test clean and flag the categories where adulteration is rampant.