This is a research-based review, not a hands-on test — see our editorial policy for how we evaluate supplements.
What it is
Thorne Magnesium Bisglycinate is a powdered magnesium supplement providing 200 mg of elemental magnesium per scoop (3.77 g), in the bisglycinate (glycinate) form — the form generally best tolerated for digestive comfort, as covered in our magnesium ingredient guide. It’s lightly sweetened with monk fruit and mixed into water or juice rather than taken as a capsule.
Dosage vs. the evidence
At 200 mg per serving, one scoop covers roughly half to two-thirds of the adult RDA (310–420 mg/day, which includes dietary intake), and comfortably sits under the 350 mg/day Tolerable Upper Intake Level for supplemental magnesium. The label’s suggested use of one to two scoops daily gives some flexibility, though two full scoops (400 mg) would approach the supplement-only upper limit — worth keeping in mind if you’re also getting meaningful magnesium from food.
Third-party certification
This product is NSF Certified for Sport, which verifies the product doesn’t contain any of 290+ substances banned by major athletic organizations, confirms the label accurately reflects the contents, and includes a toxicological review of ingredients. This is one of the more rigorous certifications available and matters even for non-athletes, since it’s independent confirmation that what’s on the label is actually what’s in the product.
Price
Priced around $52 for 60 servings at typical retailers (roughly $0.87/serving) as of this writing — prices vary by retailer and fluctuate over time, so treat this as a ballpark rather than current pricing.
Bottom line
A well-documented, third-party-certified magnesium glycinate product at a dose that’s easy to fit safely alongside dietary magnesium intake. The NSF certification is the standout feature here — it’s independently verified, which most magnesium supplements on the market are not.
This review is researched and fact-checked against manufacturer disclosures, third-party certification records, and government health databases (NIH). It is not written or reviewed by a licensed medical professional, and it is not a substitute for personalized medical advice — talk to your doctor before starting any new supplement, especially if you take medication or have a health condition.
Sources: Thorne: Magnesium Bisglycinate product page, NIH ODS Magnesium Fact Sheet
