Stacking Years Evidence Check

See the scientific evidence grade for supplements on iHerb, Walmart, Vitacost and Google search. No tracking.

Stacking Years Evidence Check tells you how strong the science is behind a supplement while you shop or search. On iHerb, Walmart and Vitacost product pages, and on Google search results, a small panel appears in the corner when the product or your search matches a supplement we cover. It shows: • Our evidence grade: A (strong), B (good) or C (early or limited) • A one-line summary of what the research shows • A link to the Stacking Years evidence page with the key studies behind the grade It covers 15 popular supplements, including creatine, magnesium, omega-3, vitamin D3, CoQ10, berberine, glycine, NMN/NR, urolithin A and quercetin. Click the toolbar icon to see the full list with grades. What it does not do: • It does not change any page, price or link, and adds no affiliate links or codes. • It does not collect, store or send any data. No account, no analytics, no ads. • It does not run code from the internet. All grades are built in. • It runs only on the sites listed above. You can close the panel with one click. Information only, not medical advice. Ask your doctor before starting a supplement. Stacking Years Evidence Check is independent. It is not affiliated with, endorsed by or sponsored by iHerb, Walmart, Vitacost, Google or any other store or search engine. All trademarks belong to their owners.