NOW Foods uses a combination of rigorous in-house laboratory testing and selective third-party certification, but not every product in their lineup carries an independent third-party seal. Some products are certified by organizations like Informed Sport, and the company’s manufacturing facilities have been certified under Good Manufacturing Practices (GMP) standards audited by UL Solutions. The short answer: NOW does more testing than most supplement brands, though the specifics depend on which product you’re looking at.
What NOW Tests In-House
NOW Foods operates an extensive analytical laboratory at its main manufacturing site in Bloomingdale, Illinois, and a second lab in Sparks, Nevada. These aren’t basic quality-check setups. Both labs hold ISO/IEC 17025 accreditation, the same international standard that governs the competence of independent testing and calibration laboratories worldwide. That accreditation is verified through 2027.
As of 2025, the labs have 14 accredited chemistry methods covering areas like heavy metal testing, vitamin C quantification, fatty acid analysis of oils, allergen detection, and multi-pesticide residue screening for over 425 pesticide compounds. The microbiology lab expanded from 6 to 12 accredited methods, including PCR-based detection of pathogens like Salmonella and Listeria. In practical terms, this means NOW can test for contaminants, verify that what’s on the label matches what’s in the bottle, and screen for a wide range of pesticide residues, all without sending samples to an outside lab.
This level of in-house capability is unusual in the supplement industry. Most brands rely entirely on contract labs or do minimal testing. NOW’s ISO accreditation means their internal results are held to the same standard an independent lab would need to meet.
Which Products Are Third-Party Certified
Select NOW products carry certification from Informed Sport, a third-party organization that tests supplements to verify they’re free of banned substances. This certification matters most for athletes subject to anti-doping regulations, but it also serves as an independent check that what’s in the bottle matches the label. You’ll find the Informed Sport logo on those specific products.
However, the majority of NOW’s product line does not carry a third-party certification seal from organizations like USP or NSF International. This is common across the supplement industry, where third-party certification is voluntary and expensive. The absence of a seal doesn’t necessarily mean a product wasn’t tested. It means it wasn’t submitted to one of those specific certification programs.
GMP Certification and Manufacturing Standards
NOW was one of the first supplement companies to earn GMP certification through UL Solutions, which audits facilities against the Natural Products Association’s GMP standard. This certification covers the manufacturing process itself: how ingredients are sourced, stored, handled, and turned into finished products. Companies that pass these audits can use the co-branded NPA and UL certification logo on their packaging and marketing.
GMP certification is different from product-level third-party testing. It confirms that the factory follows consistent, documented procedures designed to prevent contamination, mislabeling, and quality failures. Think of it as a baseline guarantee that the facility is run professionally, while product-specific certifications like Informed Sport verify individual items.
NOW’s Public Testing of Competitor Products
One thing that sets NOW apart is a transparency initiative they’ve run since around 2017. The company purchases supplements from lesser-known brands sold on Amazon, tests them in their own labs, and publishes the results. They’ve tested categories like St. John’s wort and curcumin, looking at potency, label accuracy, heavy metal levels, and whether products contain synthetic adulterants.
NOW shares these results with the FDA, FTC, and Amazon directly. According to the company’s CEO, Jim Emme, this program has led to contract manufacturers improving their practices after being flagged. Over the years, the initiative has produced roughly a dozen cases where brands corrected quality issues after NOW’s testing brought problems to light. While this doesn’t directly prove anything about NOW’s own products, it signals a company willing to put its testing capabilities on public display and hold the broader industry accountable.
What This Means for You
If you’re specifically looking for a supplement with an independent third-party certification logo on the label, check the individual product. NOW’s Informed Sport-certified items will display that clearly. For everything else, you’re relying on NOW’s in-house testing infrastructure, which is ISO-accredited and more sophisticated than what most supplement companies operate.
The practical distinction matters less than it might seem. An ISO 17025-accredited lab produces results that are recognized as equivalent to independent lab results. The accreditation itself is granted by an outside body and requires ongoing compliance. So while the testing happens inside NOW’s own facility, it’s not a case of the company grading its own homework without oversight.
If third-party certification from a specific organization like USP or NSF is important to you, NOW’s catalog has limited options. But if your concern is whether the products are genuinely tested for purity, potency, and contaminants, NOW’s testing program is among the more transparent and well-documented in the industry.