Magnesium citrate is 11.3–16.2% magnesium by weight and malate 12.6–15.5%, so 200 mg of magnesium takes 1,240–1,770 mg of citrate or 1,290–1,580 mg of malate. The ranges overlap, so the two can carry the same magnesium per gram; which end applies depends on the citrate type and the hydrate, and labels rarely say. Label counts come from the NIH Dietary Supplement Label Database (DSLD) snapshot of 2026-08-10; prices come from Amazon offers observed 2026-10-26 to 2026-11-02 and are compared only inside one salt.
Which to pick for what
At 400 mg of magnesium, both salts need 4–5 size 00 capsules of salt alone: 2,480–3,540 mg of citrate or 2,570–3,170 mg of malate, by the formulas Mg₃(C₆H₅O₇)₂ and MgC₄H₄O₅ at 0.8 g/mL.
- Fewest capsules. For 200 mg of magnesium, either salt needs 2–3 size 00 or 2 size 000 capsules. For 400 mg, either needs 4–5 size 00; in size 000, citrate needs 3–4 and malate 3. Counts assume salt alone at 0.8 g/mL: 730 mg per size 00, 1,100 mg per size 000.
- Lowest cost inside each salt. 30 days at 400 mg a day from the cheapest ranked citrate offer: $4.13. From the cheapest ranked malate offer: $5.52. At the median ranked offer, citrate: $13.90; malate: $12.62. These are within-salt figures, not a ranking of the salts.
- What studies measured. Two studies in the site's PubMed-checked registry include both salts, one of them in rats:
- PMID 30761462 (2020): absorption of oxide, citrate, glycinate and malate was profiled across several doses, so a comparison at one dose need not hold at another.
- PMID 29679349 (2019): rats received one dose of sulfate, oxide, acetyl taurate, citrate or malate; serum and tissue magnesium, brain included, were followed for hours.
- PMID 29425476 (2018): 91 adults, 53 of them on a timed-release dimagnesium malate tablet with B vitamins and folate, the rest on placebo; serum and red-cell magnesium were measured. Dimagnesium malate is not the malate in this table.
- For citrate: PMID 2407766 (1990) measured how citrate and oxide dissolve in acid, and PMID 35041150 (2022) measured ionized and total serum magnesium in 61 young women after 10 days of citrate, oxide or carbonate.
Side by side
For 400 mg of magnesium, citrate takes 2,480–3,540 mg of compound and malate 2,570–3,170 mg; label counts are from the DSLD snapshot of 2026-08-10 and prices were observed 2026-10-26 to 2026-11-02.
| Measure | Magnesium citrate | Magnesium malate |
|---|---|---|
| Magnesium by weight | 11.3–16.2% | 12.6–15.5% |
| Compound for 400 mg of magnesium | 2,480–3,540 mg | 2,570–3,170 mg |
| Size 00 capsules for 400 mg (salt alone) | 4–5 | 4–5 |
| Most magnesium one size 000 capsule can hold | 124–178 mg | 139–171 mg |
| Labels in NIH DSLD naming the salt | 212 | 73 |
| Median magnesium per serving on those labels | 235 mg | 321 mg |
| Ranked US price offers | 12 | 4 |
| Lowest price per 100 mg of magnesium, within the salt | $0.0344 | $0.0460 |
Compound masses are rounded to the nearest 10 mg.
What to check on the label
In the DSLD snapshot of 2026-08-10, 135 of 212 citrate labels and 20 of 73 malate labels name that salt as the only magnesium source.
- Which citrate. Trimagnesium dicitrate is 16.2% magnesium; dibasic and hydrated forms go as low as 11.3%.
- Dimagnesium malate. It carries more magnesium per gram than magnesium malate, so the 12.6–15.5% figure does not apply; the site lists it on its own salt page.
- Malic acid and citric acid. Listed as their own ingredients, they are free acids and add no magnesium.
- Magnesium or compound? Supplement Facts should state the magnesium itself. As compound weight, 1,000 mg of citrate holds 113–162 mg of magnesium and 1,000 mg of malate 126–155 mg.
- Per-capsule ceiling. One size 000 capsule holds at most 124–178 mg of magnesium as citrate alone and 139–171 mg as malate at 0.8 g/mL. The label audit lists labels above their capsule.
Where to go next
The citrate ranking and the malate ranking order 12 and 4 ranked offers by price per 100 mg of magnesium, prices observed 2026-10-26 to 2026-11-02.