How We Choose Brands
Supplement Facts
1Serving size 2 capsules
Amount per serving% DV
2Magnesium (as magnesium bisglycinate)200 mg · 48%
3Other ingredients: cellulose capsule, rice flour
4Certification seal · Lot # · Best by
- 1Serving size. The amounts listed are per serving, which may be more than one capsule.
- 2The form. The part in parentheses tells you which form you're getting.
- 3Other ingredients. Fillers, coatings, and colors are listed here.
- 4Seal and lot number. Look the product up on the certifier's own site, and keep the lot number in case you need a lab report.
Every brand on our Where to Buy page has to meet at least one of these standards:
- Third-party certification. The specific product is listed on a certifier’s own website, such as NSF or USP. We check the certifier’s listing directly, not the brand’s claim.
- Published lab reports. Where no certified option exists, the brand publishes batch lab reports (certificates of analysis) for the product.
- Standardized branded ingredients. The product uses a standardized, branded ingredient, such as NSK-SD for nattokinase.
Each product card on the Where to Buy page shows which standard it meets. Certifications change, so we re-check our listings regularly, and we recommend checking the label before you buy.
We may earn a commission when you buy through our links. Commissions never decide what makes the list.