How do you check that a supplement is NSF Certified for Sport?

Listing counts on this page are from our read of Sep 23, 2026

Search NSF's own directory, open the product's listing, and read its Package Size line against the package you are buying. The search results are not enough on their own. When we read them, they showed a product name and a company name. The sizes were on each listing's own page. These steps show what a listing names. What they do not settle is further down.

The steps

1. Search NSF's directory. Go to NSF's Certified for Sport directory and search for the product or the brand. NSF also has a Certified for Sport app. We opened one listing in it on Sep 24, 2026. Its search box asked for a name, a brand, an ingredient or a lot number.
2. Open the listing itself. Do not stop at the results page. When we read that page on Sep 23, 2026, each result showed the product name and the company name and nothing else.
3. Read the Package Size line. Compare it with the size printed on the package you are buying. The line is a list. Of the 710 listings we have read, 181 name more than one size, the largest names 8, and the other 529 name exactly one.
4. Read the rest of the listing the same way. Compare the product name, the Product Form line (powder, capsule, softgel and so on) and the Serving Size line with the package too.
5. Check again on the day you buy. A listing can be added, changed or removed after anyone last read it, this site included. NSF's page is the record.

What the listing does not settle

• A size that is not on the line. Our reading is that a listing names the sizes it covers, so this site counts a listing only for a package it names. That reading is ours and not NSF's. We have put the question to NSF in writing. Whether a listing covers a size it does not name is NSF's to say.
• Lot numbers. A listing also prints lot numbers. This site reads store pages, where we have not seen lot numbers shown, so it does not use lots. What a lot that is not on a listing means is NSF's to say.
• What an athlete may take. This page is about reading a listing. The rules of a sport, and the people who run its testing, decide what counts for an athlete.

Other certifiers list differently

Informed Sport, Informed Choice and IFOS list products, and none of them names a package size. USP Verified names a product and a strength and puts its mark on the label, so there the check is two things at once: the product in USP's directory, and the mark on the package's own label. What NSF Certified for Sport, USP Verified, Informed Sport and Informed Choice each test is on NSF Certified for Sport vs Informed Sport vs Informed Choice.

The same check, already done

• The Package Size line of 710 listings, in one file. On the NSF pages we have read, the line shows one listing at a time. The file puts 981 package sizes side by side, each with a link to the listing it was read from.
• NSF Certified for Sport supplements: brands and packages. The packages we price whose listing names them, beside the ones whose listing names a different size, flavor or form.

Every category we compare: the home page. Every question we answer: the question index.

Found an error? Tell us. The full method: How we compare.