Magnesium Oxide vs. Magnesium Citrate
Among 6,062 on-market magnesium products with an identifiable primary form, 52.4% use Magnesium Oxide (3,177 products) and 25.3% use Magnesium Citrate (1,533).
| Magnesium Oxide | Magnesium Citrate | |
|---|---|---|
| Quality tier | Tier 3 | Tier 1 |
| Magnesium by weight | 60.3% | 16.2% |
| Share of market | 52.4% | 25.3% |
| On-market products | 3,177 | 1,533 |
| Median declared dose | 100 elemental mg middle half: 47.38–140 | 75 elemental mg middle half: 24–150 |
| Most common brands | DC, Wonder Laboratories, GNC Mega Men | Pure Encapsulations, Ultima, Douglas Laboratories |
Doses are declared per serving in elemental mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).
Why Magnesium Oxide is tier 3
Virtually insoluble in water, only ~43% soluble even under peak gastric acid.
Source: Lindberg JS et al. 1990, J Am Coll Nutr 9(1):48-55, PMID 2407766
Why Magnesium Citrate is tier 1
Far more soluble than oxide across physiological pH, with a higher urinary Mg rise after a 25 mmol oral load (Lindberg 1990); produced the greatest serum and salivary Mg response of the three forms tested in a 60-day human RCT (Walker 2003).
Source: Lindberg 1990, PMID 2407766; Walker AF et al. 2003, Magnesium Research 16(3):183-191, PMID 14596323
Other magnesium comparisons
- Magnesium Oxide vs. Magnesium Glycinate
- Magnesium Oxide vs. Magnesium Aspartate
- Magnesium Oxide vs. Magnesium Amino Acid Chelate
- Magnesium Citrate vs. Magnesium Glycinate
- Magnesium Citrate vs. Magnesium Aspartate
- Magnesium Citrate vs. Magnesium Amino Acid Chelate
- Magnesium Glycinate vs. Magnesium Aspartate
- Magnesium Glycinate vs. Magnesium Amino Acid Chelate
- Magnesium Aspartate vs. Magnesium Amino Acid Chelate