Short answer: NSF Certified for Sport and Informed-Sport are the strictest for banned-substance screening and are what drug-tested athletes look for. USP Verified focuses on identity, potency, and purity for everyday supplements. Clean Label Project focuses on contaminants such as heavy metals and pesticides. They are not interchangeable, and a product can carry one without meeting the bar of another.
The four seals at a glance
| Program | Main focus | Best for | Banned-substance screen |
|---|---|---|---|
| NSF Certified for Sport | Identity, potency, contaminants, banned substances | Drug-tested athletes | Yes, ~280 substances |
| Informed-Sport | Banned substances, batch by batch | Athletes, UK and global | Yes, every batch |
| USP Verified | Identity, potency, purity | Everyday supplements | No |
| Clean Label Project | Heavy metals, pesticides, contaminants | Clean-focused brands, protein, baby food | No |
NSF Certified for Sport
The strictest of the four. It confirms the product contains what the label says, is free of contaminants, and passes a screen for roughly 280 substances banned in sport. It is required or recommended by the NFL, MLB, PGA, and most NCAA programs. If you are drug tested, this is the seal that matters most.
Informed-Sport
The main alternative to NSF for athletes, strong in the UK and Europe. Its distinguishing feature is batch-by-batch testing: every production run is screened, not just a one-time certification. That difference matters, because a one-time certificate says nothing about the run your bottle came from.
USP Verified
Run by the US Pharmacopeia, the same standards body recognized in US federal law for medicines. It verifies identity, potency, and purity, and is common on multivitamins and mainstream supplements. It does not run a sport banned-substance screen, so it is not a substitute for NSF Certified for Sport if you compete.
Clean Label Project
Focused on what is not supposed to be there: heavy metals, pesticides, and plasticizers. You see it most on protein powders, baby food, and brands that market on purity. It is a contaminant lens, not an identity-or-potency guarantee, so it answers a different question than USP or NSF.
Which one should you look for?
- You get drug tested: NSF Certified for Sport or Informed-Sport, no exceptions.
- You want everyday quality assurance: USP Verified.
- You care most about heavy metals and contaminants: Clean Label Project.
- You want the actual lab numbers, not just a seal: look up the published certificate. ScanCheck indexes 20,407 of them across 1,174 brands, so you can see the batch, lab, date, and method behind the seal.
Full program directory at /labs/. Related: Informed-Sport vs NSF Certified for Sport and USP Verified vs NSF Certified.