Some of the links inside a report — usually the retailer button near the bottom of a dossier — are affiliate links. If you click through and buy from an authorized retailer, we link to authorized retailers and may earn a commission at no extra cost to you. The price you pay doesn't change either way; the commission comes out of the retailer's own margin, not your wallet.
The Federal Trade Commission requires any site with a financial stake in a recommendation to say so clearly, regardless of how genuinely the writer means the recommendation. That rule exists because a reader can't judge how much weight to give a review without knowing whether the reviewer gets paid when it's followed. This page is that disclosure, and a shorter version of it sits in the footer of every page on the site.
The letter grade on an entry is decided by reading the manufacturer's claims against the available research — full human trials, thin pilot data, animal-only studies, or nothing published at all — before anyone on the desk considers whether an affiliate relationship exists for that product. Commission rates aren't part of that conversation, and a product with an affiliate link attached can still land a Grade C if the formula disclosure or the evidence doesn't hold up. Several entries in the current index do exactly that.
Links to a published study, a government agency page, a clinical guideline, or a manufacturer's own safety data sheet are citations, not affiliate links — nobody gets paid when you click one of those. The commercial links are specifically the retailer buttons on dossier pages and any similarly marked "buy" or "check price" link inside a report.
Entries are built from publicly available material — ingredient panels, published studies, manufacturer disclosures, and, where they exist, independent lab or third-party testing results — not from review units supplied by a brand and not from a paid placement. We don't accept payment in exchange for coverage, and we don't accept payment in exchange for a specific grade.
Nothing on this site, including a grade or a ranking, is intended to diagnose, treat, cure, or prevent any disease. Talk to a healthcare provider before starting any new supplement.
Federal Trade Commission — Guides Concerning the Use of Endorsements and Testimonials in Advertising (16 CFR Part 255).