A walk down the supplement aisle can lead to more questions than answers, as you wonder about the quality, safety, and potency of various products. That’s where third-party testing comes in, offering an additional layer of comfort when selecting a supplement. Choosing only third-party certified supplements is a reliable choice! But to be truly supplement-savvy, it’s important to understand what this type of testing actually means. 

A quick definition: “Third-party testing generally means a product has been tested by an independent organization rather than the manufacturer,” says John Travis, a Senior Scientific Strategist and Advisor for NSF, an independent global organization that offers third-party testing. In other words, a company outside of the supplement brand evaluates the product to verify quality and safety. 

According to Leah Murnane, M.S., R.D., C.S.S.D., L.D.N., a performance dietitian and owner of Lettuce Eat Dessert, third-party testing helps ensure that “what is listed on the label is actually what is in the product, as well as there are no added ingredients not listed on the label.”

Evaluating supplement labels on your own can be challenging. Third-party testing aims to help clear up the confusion. Here’s a closer look at what happens when products like vitamins, minerals, and protein powders undergo third-party testing.

• ABOUT OUR EXPERTS: John Travis is a Senior Scientific Strategist and Advisor for NSF. Leah Murnane, M.S., R.D., C.S.S.D., L.D.N., a performance dietitian and owner of Lettuce Eat Dessert. Leslie Getzinger, M.S., R.D.N. is a dietitian and consultant based in Orange, California.
  

What Does Third-Party Testing Involve?

The exact scope of testing depends on the organization conducting it and their certification program requirements. Generally, third-party testing assesses whether the ingredients listed on the supplement label are actually present, whether the dose matches what is listed, and whether the product contains contaminants or banned substances. “The scope of testing depends on the organization requesting it,” says Travis. “If a test is not requested, it’s not performed.” The onus is on the supplement company—not the testing agency—to request certain tests. 

Common testing categories may include:

• • Identity: Is the ingredient what the label says it is?
  • Potency: Does the product contain the listed amount?
  • Purity: Is the product free from unacceptable levels of contaminants
  • Disintegration: How well does the supplement break down and get absorbed?
  • Label accuracy: Does what’s in the bottle match what’s on the label?
  • Banned substances: Has the product been screened for substances prohibited by major athletic organizations?  

Third-Party Testing vs. Third-Party Certification

“Third-party testing generally refers to testing conducted at a specific point in time, but it doesn’t necessarily communicate the outcome of that testing or how the results were evaluated,” explains Travis. In other words, just because something has been tested doesn’t mean it’s earned a seal of approval from an independent organization. That’s what certification is for.

Read More: How to Read a Certificate of Analysis (COA) 

Certification means a product has not only been tested, but has passed a testing agency’s requirements. How to know a product has met these standards? Those little labels and seals that appear on supplements saying they’ve been vetted by an independent organization (like NSF, ConsumerLabs, USP, and others). 

Depending on the third party’s program, Travis says certification may check a variety of boxes. These might include evaluating testing results, performing facility audits, verifying label claims, and ongoing monitoring. Independent certification holds organizations to a higher standard, providing transparency about what’s really going on behind the scenes in supplements and their manufacturing sites.

Long story short: A certification seal means a product has passed third-party testing—a rigorous quality assurance control designed to give you more confidence in the safety, potency, and reliability of your supplement. 

What Does Third-Party Testing Not Tell You?

While third-party testing tells you important info about supplements from alpha galactosidase to omega-3s, it doesn’t tell you everything. Notably, third-party testing only reflects the result of a test performed at a specific point in time. While supplements may meet industry standards at the time of testing, things can always change. “Depending on the program, [testing] may not include broader information, such as ongoing manufacturing oversight, continued monitoring, or the full scope of product evaluation,” shares Travis. 

Furthermore, third-party testing doesn’t tell you if the supplement is appropriate for your unique health needs, what outcome you may experience, and if it’ll be safe for you, given your medical history. That’s where it’s helpful to work with a healthcare professional like your doctor or a registered dietitian.

Read More: 7 Possible Reasons Why Your Supplement Isn’t Working

How to Know a Product Is Third-Party Tested

When shopping for a third-party-tested supplement, look for an official seal or logo, says Leslie Getzinger, M.S., R.D.N. “The most common testing agencies are USP, NSF, Informed Choice, and Consumer Lab,” she adds. While these are reputable and reliable testing certifications, you may still want to do your own research on what the third-party testing or certification label means. Not all programs evaluate the same things, cautions Travis. Look on the certification’s website to understand specifically what’s being tested.

All of The Vitamin Shoppe house brand products are third-party tested, so you can have greater confidence in the supplements you take. Vitamin Shoppe requires rigorous testing of ingredient purity and potency and maintains stringent product specifications to ensure all supplements meet FDA guidelines and good manufacturing practices.

The Bottom Line

Looking for recognized third-party seals (and doing your own research about what those certifications include) can help you confidently navigate the supplement aisle. By choosing third-party-certified supps, you’ll have assurance you’re getting quality, safety, purity, and an absence of banned substances.