Supplement Brand Quality Guide
Supplements reach store shelves without any government check of what is inside, and independent testing keeps finding labels that do not match the contents. This guide lists products we confirmed in NSF’s public certification directories, and shows you how to check any other product yourself.
Why third-party certification matters
In the United States, the FDA does not approve dietary supplements before they are sold, does not routinely test what is in them, and generally does not approve their labels (FDA). No regulator reviews a supplement’s quality before it reaches the market.1 Independent testing shows why that matters: in a 2022 analysis of 30 immune-support supplements bought on Amazon, only 13 had accurate labels.2 Of 272 supplements collected from people with suspected supplement-related liver injury, 51% did not contain what their labels said, though these were products already under suspicion.3 From 2007 to 2016, the FDA identified 776 supplements containing hidden drug ingredients, most sold for sexual enhancement, weight loss or muscle building.4
Certification programs fill part of that gap, but each tests different things.1 None of them tells you whether a supplement works; for that, see our Supplement Evidence Database.
USP Verified
The USP Verified Mark means a product contains the listed ingredients in the declared amounts, does not contain harmful levels of specified contaminants, and breaks down in the body within a set time. Manufacturers also pass a facility audit and off-the-shelf retesting (USP). Search USP Verified products.
NSF/ANSI 173
NSF certifies that a product contains the identity and quantity of ingredients on its label and no unacceptable levels of contaminants, according to the note on each NSF listing. Search NSF’s dietary supplement listings.
NSF Certified for Sport
NSF’s sport program adds testing for substances banned in sport and is recognized by the US Anti-Doping Agency, Major League Baseball, the NHL and the CFL (NSF). Search certified products.
Informed Sport
A program designed to protect athletes from supplements contaminated with banned substances. It notes that labels such as “approved by WADA” are meaningless, because anti-doping bodies do not approve supplements (Informed Sport).
ConsumerLab
A subscription service that tests products for identity, strength and purity and publishes the results (ConsumerLab). Its approval lists are behind a paywall, so we do not reproduce them here.
cGMP (good manufacturing practice)
FDA rules require every company that makes, packages or holds supplements to follow current good manufacturing practices (FDA). A “cGMP” claim on a label is the legal floor, not an FDA certification and not proof of testing.
How to read a supplement label
- Look for a seal you can verify: search the product in the certifier’s own directory; a seal printed on a label or website is not proof on its own.
- Check the amount of each ingredient: “proprietary blends” list only a total weight, so you cannot see how much of each ingredient you get.
- Check the form: the same nutrient comes in different chemical forms (for example, magnesium oxide or magnesium glycinate) that deliver different amounts of the mineral per pill.
- Read “Other ingredients”: this lists everything in the capsule besides the active ingredients.
- Ask for a certificate of analysis: some companies publish lab results for each batch; a company that will not name its lab is not offering independent proof.
| Brand | Supplement | Product (as listed by NSF) | Certification | Check it yourself |
|---|---|---|---|---|
| Thorne | Vitamin D3 | Thorne® Vitamin D3 (liquid) | NSF/ANSI 173 | NSF 173 listing |
| Thorne | Omega-3 / fish oil | Thorne® Super EPA (EPA & DHA) | NSF Certified for Sport | NSF Sport listing |
| Thorne | Magnesium | Thorne® Magnesium Bisglycinate | NSF/ANSI 173 NSF Certified for Sport | NSF 173 listing · NSF Sport listing |
| Thorne | Creatine | Thorne® Creatine | NSF Certified for Sport | NSF Sport listing |
| Thorne | B complex | Thorne® Basic B Complex | NSF/ANSI 173 | NSF 173 listing |
| Thorne | Curcumin | Thorne® Curcumin Phytosome | NSF/ANSI 173 NSF Certified for Sport | NSF 173 listing · NSF Sport listing |
| Nordic Naturals | Omega-3 / fish oil | Ultimate Omega 2X Sport | NSF Certified for Sport | NSF Sport listing |
| Momentous | Creatine | Momentous Creatine | NSF Certified for Sport | NSF Sport listing |
| Momentous | Omega-3 / fish oil | Momentous Omega-3 | NSF/ANSI 173 NSF Certified for Sport | NSF 173 listing · NSF Sport listing |
| Momentous | Magnesium | Momentous Magnesium Threonate | NSF Certified for Sport | NSF Sport listing |
| Tru Niagen | NR (NAD+ precursor) | TRU NIAGEN® (nicotinamide riboside) | NSF Certified for Sport | NSF Sport listing |
| Klean Athlete | Creatine | Klean Athlete® Klean Creatine | NSF/ANSI 173 NSF Certified for Sport | NSF 173 listing · NSF Sport listing |
| Vital Proteins | Collagen | Vital Proteins® Collagen Peptides | NSF Certified for Sport | NSF Sport listing |
| Core Med Science (OIAM) | Ashwagandha | Ashwagandha KSM-66 600 mg | NSF/ANSI 173 NSF Certified for Sport | NSF 173 listing · NSF Sport listing |
Every product above was found in NSF’s public directories on October 4, 2026. Certifications lapse and change, so open the listing before you buy. A product missing from this table may still be certified by USP, Informed Sport or ConsumerLab; use their lookups above. A listing here is not an endorsement and says nothing about whether the supplement works.
Red Flags — Signs of a Low-Quality Supplement Brand
- Proprietary blends — hides individual ingredient doses behind a total blend weight
- No third-party testing — claims "lab tested" but won't name the lab or show results
- "FDA approved": the FDA does not approve dietary supplements before they are sold, so this claim is false
- Exaggerated health claims — "cures," "reverses aging," "proven to extend lifespan"
- Amazon-only brands with no company website, no COA, and thousands of suspiciously uniform reviews
- Celebrity/influencer brands — endorsement is not evidence; check for third-party testing
Method, limits and how to read your result
How it works
Each row is a product we found by name in NSF’s public NSF/ANSI 173 directory or its Certified for Sport directory on October 4, 2026. The product name is copied from the listing, and the link opens the live listing so you can confirm it is still current.
Limits
The table covers only NSF programs, because USP’s directory could not be checked automatically and ConsumerLab’s results are paid. We removed earlier entries we could not confirm, including some products previously described as NSF certified. Certification programs check label accuracy and contaminants with different methods, not effectiveness (reference 1).
How to read your result
Use the table as a starting point, not a shopping list: confirm the exact product and size in the certifier’s directory, then check whether the supplement itself is supported by evidence before taking it.
References
- 1Eichner AK, et al. "Essential Features of Third-Party Certification Programs for Dietary Supplements: A Consensus Statement." Curr Sports Med Rep. 2019;18(5):178-182. PubMed · DOI
- 2Crawford C, et al. "Analysis of Select Dietary Supplement Products Marketed to Support or Boost the Immune System." JAMA Netw Open. 2022;5(8):e2226040. PubMed · DOI
- 3Navarro V, et al. "The Contents of Herbal and Dietary Supplements Implicated in Liver Injury in the United States Are Frequently Mislabeled." Hepatol Commun. 2019;3(6):792-794. PubMed · DOI
- 4Tucker J, et al. "Unapproved Pharmaceutical Ingredients Included in Dietary Supplements Associated With US Food and Drug Administration Warnings." JAMA Netw Open. 2018;1(6):e183337. PubMed · DOI
Check your supplements for interactions
Once you have selected your brands, verify your stack for dangerous interactions with our Interaction Checker.
Check Interactions →