Magnesium · 9 products
What magnesium really costs, and how much of its testing you can see.
Every price is converted to cost per 100 mg of elemental magnesium, the amount on the Supplement Facts panel, not the weight of the whole compound (500 mg of magnesium glycinate holds far less than 500 mg of magnesium). Each product shows its form. Testing transparency gets its own grade, A to C, and is never blended into the price.
| Product | Cost per 100 mg | Best price | Tier | Testing |
|---|---|---|---|---|
Nature's BountyMagnesium 500 mg Tablets | $0.020 | Nature's Bounty$10.16 / 100 servingsChecked Oct 22, 2026 | C | No current certificationNo COA found |
Nature MadeMagnesium Oxide 250 mg Tablets | $0.032 | Fred Meyer$7.99 / 100 servingsChecked Oct 22, 2026 | C | No current certificationNo COA found |
NOW FoodsMagnesium Citrate 200 mg Tablets | $0.067 | Vitacost$13.46 / 50 servingsChecked Oct 22, 2026 | C | No current certificationNo COA found |
Doctor's BestHigh Absorption Magnesium | $0.100 | Vitacost$23.99 / 120 servingsChecked Oct 22, 2026 | C | No current certificationNo COA found |
Nature MadeMagnesium Glycinate 200 mg Capsules | $0.18 | H-E-B$10.68 / 30 servingsChecked Oct 22, 2026 | C | No current certificationNo COA found |
Pure EncapsulationsMagnesium (Glycinate) | $0.21 | Vitacost (360 capsules)$89.61 / 360 servingsChecked Oct 22, 2026 | C | No current certificationNo COA found |
Klean AthleteKlean Magnesium 90 Capsules | $0.25 | Klean Athlete$26.50 / 90 servingsChecked Oct 22, 2026 | B | NSF Certified for SportNo COA found |
ThorneMagnesium Bisglycinate | $0.43 | Thorne$52.00 / 60 servingsChecked Oct 22, 2026 | B | NSF Certified for SportNo COA found |
Life ExtensionNeuro-Mag Magnesium L-Threonate 90 Vegetarian Capsules | $0.73 | Vitacost$31.50 / 30 servingsChecked Oct 22, 2026 | C | No current certificationNo COA found |
No products match these filters.
What the tiers mean
- A
- A current third-party certification and a COA from an ISO/IEC 17025 accredited lab, testing the finished product, less than 2 years old.
- B
- Some proof of testing (a COA or a certification), but not everything Tier A needs.
- C
- No COA and no certification found.
Prices are read from each store's own page and marked stale after 14 days. A certification counts only if it appears on the certifier's own website. Star ratings are each store's own customer reviews, shown for reference; they never affect the order of the table.