Same elemental magnesium · two salts · snapshot 2026-08-10
Magnesium carbonate vs lactate: 694–807 vs 1,665–1,963 mg of compound for 200 mg of magnesium
Magnesium carbonate is 24.8–28.8% elemental magnesium and magnesium lactate is 10.2–12.0%, so 200 mg of magnesium needs 694–807 mg of carbonate against 1,665–1,963 mg of lactate: 1–2 vs 3 size 00 capsules at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range. No capsule label names carbonate alone, against 0 of 1 for lactate. Neither salt has a ranked US retail price as of 2026-11-02.
computed from chemical formulas
Chart data
| Displayed chart text |
|---|
| 100 mg magnesium |
| carbonate 347–404 · lactate 833–981 |
| 200 mg magnesium |
| carbonate 694–807 · lactate 1,665–1,963 |
| 400 mg magnesium |
| carbonate 1,387–1,614 · lactate 3,331–3,925 |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-11-02 · chemistry 2026-10-17
How much carbonate or lactate carries the same elemental magnesium?
At the same elemental amount, carbonate (24.8–28.8% magnesium) always needs less compound than lactate (10.2–12.0%): for 400 mg of magnesium, 1,387–1,614 mg against 3,331–3,925 mg. That is the mass of powder per dose; how much of it is absorbed is what the studies below measured.
computed| Elemental magnesium | carbonate compound | carbonate size 00 | lactate compound | lactate size 00 |
|---|---|---|---|---|
| 100 mg | 347–404 mg | 1 | 833–981 mg | 2 |
| 200 mg | 694–807 mg | 1–2 | 1,665–1,963 mg | 3 |
| 400 mg | 1,387–1,614 mg | 2–3 | 3,331–3,925 mg | 5–6 |
carbonate: anhydrous or hydrated; labels rarely state which; lactate: anhydrous 12.01% or dihydrate 10.19% (238.48 g/mol); hydration ambiguity stays a range.
Source · Chemical formulas and NIH DSLD labels · snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Estimated salt mass versus assumed capsule capacity
No capsule label names carbonate alone, against 0 of 1 for lactate. Verdicts use the most favourable hydration and the most units per serving at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range; the audited registry as a whole has 8 of 137 capsule labels above size 000.
computed with assumption| Salt | Audited capsule labels | Fits 0 or 00 | Needs 000 | Exceeds 000 |
|---|---|---|---|---|
| carbonate | 0 | 0 | 0 | 0 |
| lactate | 1 | 1 | 0 | 0 |
Source · NIH DSLD labels; mass balance · recognized salt only; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does each cost per 100 mg of elemental magnesium, within its own salt?
No ranked US retail price is matched for either salt as of 2026-11-02.
computed| Salt | Ranked offers | Lowest per 100 mg | Median per 100 mg | Observed |
|---|---|---|---|---|
| carbonate | 0 | none | none | 2026-11-02 |
| lactate | 0 | none | none | 2026-11-02 |
Source · Amazon via licensed data provider; NIH DSLD · unique ASIN × date; prices observed 2026-10-26 to 2026-11-02 · release 2026-08-10-f441aa9f · CSV · method
Has any study measured carbonate and lactate side by side?
One study in the PubMed-checked registry measured both salts in the same design; 2 involve carbonate and 2 involve lactate in total. They measured outcomes of the salts, not of any label.
measured| Year | Study | Salts measured | PubMed |
|---|---|---|---|
| 2005 | Study of magnesium bioavailability from ten organic and inorganic Mg salts in Mg-depleted rats using a stable isotope approach | oxide, chloride, sulfate, carbonate, citrate, gluconate, lactate, aspartate, glycinate | 16548135 |
| 2022 | Effects of short-term magnesium supplementation on ionized, total magnesium and other relevant electrolytes levels. | oxide, citrate, carbonate | 35041150 |
| 2001 | Bioavailability of US commercial magnesium preparations | oxide, chloride, lactate, aspartate | 11794633 |
Source · PubMed-checked study registry · registry checked 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How many labels name both carbonate and lactate?
No label names both carbonate and lactate as of 2026-08-10, against 23 labels naming carbonate and 6 naming lactate.
measured| Label | Declared elemental per serving | NIH DSLD |
|---|---|---|
| No label as of 2026-08-10 |
Source · Chemical formulas and NIH DSLD labels · snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does every dose from 25 to 1,000 mg of magnesium need in each salt?
The table converts 40 elemental amounts, 25 to 1,000 mg in 25 mg steps, into compound mass and size 00 capsules for both salts, against 730 mg per size 00 capsule at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range. The first eight rows are shown; the rest open below.
computed| Elemental magnesium | carbonate compound | carbonate size 00 | lactate compound | lactate size 00 |
|---|---|---|---|---|
| 25 mg | 87–101 mg | 1 | 208–245 mg | 1 |
| 50 mg | 173–202 mg | 1 | 416–491 mg | 1 |
| 75 mg | 260–303 mg | 1 | 624–736 mg | 1–2 |
| 100 mg | 347–404 mg | 1 | 833–981 mg | 2 |
| 125 mg | 434–504 mg | 1 | 1,041–1,227 mg | 2 |
| 150 mg | 520–605 mg | 1 | 1,249–1,472 mg | 2–3 |
| 175 mg | 607–706 mg | 1 | 1,457–1,717 mg | 2–3 |
| 200 mg | 694–807 mg | 1–2 | 1,665–1,963 mg | 3 |
32 additional rows
| Elemental magnesium | carbonate compound | carbonate size 00 | lactate compound | lactate size 00 |
|---|---|---|---|---|
| 225 mg | 780–908 mg | 2 | 1,873–2,208 mg | 3–4 |
| 250 mg | 867–1,009 mg | 2 | 2,082–2,453 mg | 3–4 |
| 275 mg | 954–1,110 mg | 2 | 2,290–2,699 mg | 4 |
| 300 mg | 1,041–1,211 mg | 2 | 2,498–2,944 mg | 4–5 |
| 325 mg | 1,127–1,312 mg | 2 | 2,706–3,189 mg | 4–5 |
| 350 mg | 1,214–1,412 mg | 2 | 2,914–3,435 mg | 4–5 |
| 375 mg | 1,301–1,513 mg | 2–3 | 3,122–3,680 mg | 5–6 |
| 400 mg | 1,387–1,614 mg | 2–3 | 3,331–3,925 mg | 5–6 |
| 425 mg | 1,474–1,715 mg | 3 | 3,539–4,171 mg | 5–6 |
| 450 mg | 1,561–1,816 mg | 3 | 3,747–4,416 mg | 6–7 |
| 475 mg | 1,648–1,917 mg | 3 | 3,955–4,661 mg | 6–7 |
| 500 mg | 1,734–2,018 mg | 3 | 4,163–4,907 mg | 6–7 |
| 525 mg | 1,821–2,119 mg | 3 | 4,371–5,152 mg | 6–8 |
| 550 mg | 1,908–2,220 mg | 3–4 | 4,580–5,397 mg | 7–8 |
| 575 mg | 1,994–2,320 mg | 3–4 | 4,788–5,643 mg | 7–8 |
| 600 mg | 2,081–2,421 mg | 3–4 | 4,996–5,888 mg | 7–9 |
| 625 mg | 2,168–2,522 mg | 3–4 | 5,204–6,133 mg | 8–9 |
| 650 mg | 2,255–2,623 mg | 4 | 5,412–6,379 mg | 8–9 |
| 675 mg | 2,341–2,724 mg | 4 | 5,620–6,624 mg | 8–10 |
| 700 mg | 2,428–2,825 mg | 4 | 5,828–6,869 mg | 8–10 |
| 725 mg | 2,515–2,926 mg | 4–5 | 6,037–7,115 mg | 9–10 |
| 750 mg | 2,601–3,027 mg | 4–5 | 6,245–7,360 mg | 9–11 |
| 775 mg | 2,688–3,128 mg | 4–5 | 6,453–7,605 mg | 9–11 |
| 800 mg | 2,775–3,228 mg | 4–5 | 6,661–7,851 mg | 10–11 |
| 825 mg | 2,862–3,329 mg | 4–5 | 6,869–8,096 mg | 10–12 |
| 850 mg | 2,948–3,430 mg | 5 | 7,077–8,342 mg | 10–12 |
| 875 mg | 3,035–3,531 mg | 5 | 7,286–8,587 mg | 10–12 |
| 900 mg | 3,122–3,632 mg | 5 | 7,494–8,832 mg | 11–13 |
| 925 mg | 3,208–3,733 mg | 5–6 | 7,702–9,078 mg | 11–13 |
| 950 mg | 3,295–3,834 mg | 5–6 | 7,910–9,323 mg | 11–13 |
| 975 mg | 3,382–3,935 mg | 5–6 | 8,118–9,568 mg | 12–14 |
| 1,000 mg | 3,469–4,036 mg | 5–6 | 8,326–9,814 mg | 12–14 |
Source · Chemical formulas and NIH DSLD labels · snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method