How we rate supplements.

Cite every claim.

Every product, dose, and price links to a verifiable source. We name the date and URL.

Marketing claims are called out as marketing claims. If a brand says "clinically proven" without a published study we will note that in the comparison. We never cite a brand's own website as the source for a clinical claim about the brand's product — only peer-reviewed primary sources count.

Bioavailability first.

A 500 mg dose that absorbs 80% beats a 1,000 mg dose that absorbs 10%. We rank absorption, not label size.

For every form on every comparison, we answer the same three questions:

1. What fraction of the dose actually reaches the bloodstream?
2. How does that fraction change with food, age, or gut health?
3. What's the active dose — the amount that does the work — versus the label dose?

When two forms genuinely trade off (e.g. magnesium oxide is cheap but absorbs poorly; magnesium glycinate is well-absorbed but more expensive per serving), we say so explicitly and rank use case, not abstract "best".

Per-effective-dose pricing.

Same dollar amount in your hand gives very different useful nutrient depending on the form. We normalise by active dose.

Every product price is converted to cost per mg of usable active, not cost per capsule or cost per serving. A 60-capsule bottle of "1000 mg vitamin C" at $20 might look cheaper than a 30-capsule bottle of "500 mg liposomal vitamin C" at $35 — but the liposomal form delivers 5–10× more active vitamin C, so the per-effective-mg price is actually lower.