Third-Party-Tested Magnesium Glycinate Brands

Magnesium glycinate is one of the most popular supplements around, which also makes it one of the easiest to cut corners on. Here’s how to find one that’s been independently tested.

What “third-party tested” should mean

Anyone can print “lab tested” on a bottle. What matters is who did the testing and whether you can check it. The strongest signals are:

• NSF Certified for Sport: tests for label accuracy, contaminants, and banned substances.
• NSF/ANSI 173: checks that the contents match the label and screens for contaminants.
• USP Verified: checks identity, strength, purity, and manufacturing.

Certified magnesium brands on our list

• Thorne (NSF Certified for Sport)
• Momentous (NSF Certified for Sport)
• BiOptimizers (NSF Certified for Sport)
• Nature Made (USP Verified)
• Ritual (NSF/ANSI 173)
• Double Wood (NSF/ANSI 173)

Certification often applies to specific products, not the whole brand, so check that the exact bottle you’re buying is listed.

How to verify it yourself

Search the product name on the NSF or USP website. If it’s not listed there, treat the seal on the bottle with caution.

Glycinate vs. bisglycinate

These names refer to the same form. Some products are “buffered,” meaning they’re mixed with cheaper magnesium oxide, so check the label for a fully reacted or 100% glycinate formula.

This article is for education, not medical advice. These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease. We may earn a commission from links on this site.