Supplement Insider Evidence-based wellness

What "strong evidence" means here

Three grades, applied to one ingredient for one outcome at a time. A grade describes the weight of human trial evidence — not safety, not quality, and not how well it will work for you.

Strong evidence We'd act on this

Several independent controlled trials, by different groups, agreeing on the same measured outcome — and a plausible mechanism.

  • At least three randomised controlled trials pointing the same way
  • Not all funded by the same manufacturer
  • An outcome that was measured, not self-reported alone
Moderate evidence Reasonable to try, with eyes open

Real positive trials exist, but they're small, narrow, or not yet replicated by an independent group.

  • Typically one or two trials, often under 100 participants
  • Effects may only appear in a specific group — deficient, older, or clinical
  • Frequently industry-funded, which we note per trial
Limited evidence We wouldn't buy it for this

The human data is absent, contradictory, or the positive findings failed to replicate at scale.

  • Cell or animal studies only, with no human trial
  • Large trials came back null after small ones looked promising
  • Commercial doses fall far below anything that was tested

What we can't grade

Proprietary blends. If doses are undisclosed, there is nothing to compare against a trial. These get no grade — which is not a neutral result, it's a reason to skip.

Whole multi-ingredient formulas. Almost no product is tested as sold. We grade the ingredients and count how many hit their studied dose; we never imply the combination was trialled.

Anything disease-related. We do not grade supplements for treating, curing or preventing a diagnosed condition. That is a question for a doctor, not a review site.

A grade can change

When new trials land we re-grade and date the change, keeping the previous conclusion visible on the page.

See every ingredient graded