Version July 2025
| Brand name examples (United States) | Magnesium salt content per pill or as shown (mg) | Elemental magnesium per pill or as shown (mmol) | Elemental magnesium content per pill or as shown (mg) | Number of pills (or as shown) daily for RDA* | |
| Oral magnesium salts | |||||
| Magnesium oxide | Uro-Mag | 140 | 3.5 | 84.5 | 4 to 5 |
| Mag-Ox 400 Mag-Oxide | 400 | 10 | 241 | 1 to 2 | |
| Magnesium chloride (hexahydrate)¶ | SlowMag SlowMag Muscle + Heart | 600 | 2.9 | 72 | 4 to 6 |
| MagDelay Slow Magnesium/Calcium | 535 | 2.6 | 64 | 5 to 7 | |
| Magnesium carbonate | Magonate oral liquid | 1000 mg per 5 mL | 2.4 mmol per 5 mL | 54 mg per 5 mL | 30 to 40 mL |
| Magnesium gluconate | Mag-G | 500 | 1.1 | 27 | 11 to 16 |
| Magnesium L-aspartate hydrochloride | Maginex (enteric coated) | 615 mg per tablet | 2.5 mmol per tablet | 61 mg per tablet | 5 to 7 tablets |
| Maginex DS granules for oral solution (packet) | 1230 mg per packet | 5 mmol per packet | 122 mg per packet | 2.5 to 4 packets | |
| Magnesium L-lactate (dihydrate)¶ | Mag-Tab SR | 833 | 3.5 | 84 | 4 to 5 |
| Intravenous magnesium | |||||
| Magnesium sulfate (heptahydrate)¶ | Sterile parenteral product available in several dilutions | 1000 | 4 | 98 | N/A |
This table lists characteristics of select magnesium preparations available in the United States. Generic (nonproprietary) formulations are also available.
Most oral magnesium products in the United States express product strength as elemental magnesium per pill (or per two pills). In some other areas, product strength may be expressed as magnesium salt content or mmol of magnesium per pill. Equivalences for these expressions are listed above; however, always check current local product information.
Refer to UpToDate content on hypomagnesemia for discussion of product selection and dosing.N/A: not applicable; RDA: recommendary dietary allowance.
* Elemental magnesium RDAs for adults ≥19 years: Males: 400 to 420 mg daily; Females: 310 to 320 mg daily; Pregnancy: 350 to 360 mg daily; Breastfeeding: 310 to 320 mg daily.
¶ Elemental content shown is for hydrate form available in United States and some other countries. Products with different hydrates are available in some other countries. Those products can have different elemental magnesium content than listed above; consult local labeling.Courtesy of Alan S L Yu, MB, BChir.
Additional data from: