Same elemental magnesium · two salts · snapshot 2026-08-10

Magnesium aspartate vs orotate: 1,279–2,670 vs 2,751 mg of compound for 200 mg of magnesium

Magnesium aspartate is 7.5–15.6% elemental magnesium and magnesium orotate is 7.3%, so 200 mg of magnesium needs 1,279–2,670 mg of aspartate against 2,751 mg of orotate: 2–4 vs 4 size 00 capsules at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range. 0 of 15 capsule labels naming aspartate alone are above the assumed size 000 capacity at powder density 0.8 g/mL, against 0 of 3 for orotate. Prices within each salt: no ranked aspartate price; orotate $0.7937 per 100 mg (a single ranked offer); observed 2026-10-26 to 2026-11-02.

computed from chemical formulas

aspartate for 200 mg Mg1,279–2,670 mg7.5–15.6% magnesium · 2–4 size 00

orotate for 200 mg Mg2,751 mg7.3% magnesium · 4 size 00

Exceeds size 0000 of 15 · 0 of 3aspartate · orotate capsule labels

Cheapest by declared elemental magnesium, per 100 mg, within each saltaspartate none · orotate $0.79370 and 1 ranked offers · 2026-11-02

Compound mass for the same elemental magnesium: dark dot aspartate (7.5–15.6%, lower mass bound), grey dot orotate (7.3%); the labels give each salt's full range.

Chart data

Chart labels and values for the main chart
Displayed chart text
100 mg magnesium
aspartate 639–1,335 · orotate 1,376
200 mg magnesium
aspartate 1,279–2,670 · orotate 2,751
400 mg magnesium
aspartate 2,558–5,340 · orotate 5,502

Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-11-02 · chemistry 2026-10-17

Elemental: The magnesium itself; the rest of the compound weight is the partner molecule.

Compound: The whole salt that must physically fit in a capsule; a lower magnesium fraction means more compound for the same magnesium.

How much aspartate or orotate carries the same elemental magnesium?

At the same elemental amount, aspartate (7.5–15.6% magnesium) always needs less compound than orotate (7.3%): for 400 mg of magnesium, 2,558–5,340 mg against 5,502 mg. That is the mass of powder per dose; how much of it is absorbed is what the studies below measured.

computed

Compound mass and size 00 capsules for aspartate and orotate
Elemental magnesium	aspartate compound	aspartate size 00	orotate compound	orotate size 00
100 mg	639–1,335 mg	1–2	1,376 mg	2
200 mg	1,279–2,670 mg	2–4	2,751 mg	4
400 mg	2,558–5,340 mg	4–8	5,502 mg	8

aspartate: 1:1 magnesium aspartate 15.64%; bis(hydrogen aspartate) 8.42%, its dihydrate 7.49%; stoichiometry and hydration unresolved; 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

0 of 15 capsule labels naming aspartate alone are above the assumed size 000 capacity at powder density 0.8 g/mL, against 0 of 3 for orotate. 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

stacked bar · aspartate vs orotate · capsule verdicts, 0 of 15 vs 0 of 3 exceed size 000 · snapshot 2026-08-10 — Capsule verdicts for labels naming each salt alone: fits size 0 or 00, needs 000, exceeds 000.

Chart data

Chart labels and values for Estimated salt mass versus assumed capsule capacity
Displayed chart text
aspartate
fits 13 of 15
needs 000 2 of 15
exceeds 0 of 15
orotate
fits 3 of 3
needs 000 0 of 3
exceeds 0 of 3

Capsule verdicts for aspartate and orotate labels
Salt	Audited capsule labels	Fits 0 or 00	Needs 000	Exceeds 000
aspartate	15	13	2	0
orotate	3	3	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?

Compared only with offers of the same salt: no ranked aspartate price; orotate $0.7937 per 100 mg (a single ranked offer). Prices observed 2026-10-26 to 2026-11-02; a ranking exists only inside one salt, because the compound mass per 100 mg of magnesium differs between salts.

computed

Price per 100 mg of declared elemental magnesium, within each salt
Salt	Ranked offers	Lowest per 100 mg	Median per 100 mg	Observed
aspartate	0	none	none	2026-11-02
orotate	1	$0.7937	$0.7937	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 aspartate and orotate side by side?

No study in the PubMed-checked registry measured aspartate and orotate side by side as of 2026-08-10; 2 involve aspartate and 0 involve orotate separately.

measured

Registry studies involving aspartate or orotate
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
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 aspartate and orotate?

No label names both aspartate and orotate as of 2026-08-10, against 46 labels naming aspartate and 8 naming orotate.

measured

Labels naming both salts
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

Compound mass reference, 25 to 1,000 mg of elemental magnesium
Elemental magnesium	aspartate compound	aspartate size 00	orotate compound	orotate size 00
25 mg	160–334 mg	1	344 mg	1
50 mg	320–668 mg	1	688 mg	1
75 mg	480–1,001 mg	1–2	1,032 mg	2
100 mg	639–1,335 mg	1–2	1,376 mg	2
125 mg	799–1,669 mg	2–3	1,719 mg	3
150 mg	959–2,003 mg	2–3	2,063 mg	3
175 mg	1,119–2,336 mg	2–4	2,407 mg	4
200 mg	1,279–2,670 mg	2–4	2,751 mg	4

32 additional rows

Compound mass reference, 25 to 1,000 mg of elemental magnesium, additional rows
Elemental magnesium	aspartate compound	aspartate size 00	orotate compound	orotate size 00
225 mg	1,439–3,004 mg	2–5	3,095 mg	5
250 mg	1,598–3,338 mg	3–5	3,439 mg	5
275 mg	1,758–3,672 mg	3–6	3,783 mg	6
300 mg	1,918–4,005 mg	3–6	4,127 mg	6
325 mg	2,078–4,339 mg	3–6	4,470 mg	7
350 mg	2,238–4,673 mg	4–7	4,814 mg	7
375 mg	2,398–5,007 mg	4–7	5,158 mg	8
400 mg	2,558–5,340 mg	4–8	5,502 mg	8
425 mg	2,717–5,674 mg	4–8	5,846 mg	9
450 mg	2,877–6,008 mg	4–9	6,190 mg	9
475 mg	3,037–6,342 mg	5–9	6,534 mg	9
500 mg	3,197–6,676 mg	5–10	6,878 mg	10
525 mg	3,357–7,009 mg	5–10	7,221 mg	10
550 mg	3,517–7,343 mg	5–11	7,565 mg	11
575 mg	3,676–7,677 mg	6–11	7,909 mg	11
600 mg	3,836–8,011 mg	6–11	8,253 mg	12
625 mg	3,996–8,344 mg	6–12	8,597 mg	12
650 mg	4,156–8,678 mg	6–12	8,941 mg	13
675 mg	4,316–9,012 mg	6–13	9,285 mg	13
700 mg	4,476–9,346 mg	7–13	9,629 mg	14
725 mg	4,636–9,680 mg	7–14	9,972 mg	14
750 mg	4,795–10,013 mg	7–14	10,316 mg	15
775 mg	4,955–10,347 mg	7–15	10,660 mg	15
800 mg	5,115–10,681 mg	8–15	11,004 mg	16
825 mg	5,275–11,015 mg	8–16	11,348 mg	16
850 mg	5,435–11,348 mg	8–16	11,692 mg	17
875 mg	5,595–11,682 mg	8–17	12,036 mg	17
900 mg	5,754–12,016 mg	8–17	12,380 mg	17
925 mg	5,914–12,350 mg	9–17	12,724 mg	18
950 mg	6,074–12,684 mg	9–18	13,067 mg	18
975 mg	6,234–13,017 mg	9–18	13,411 mg	19
1,000 mg	6,394–13,351 mg	9–19	13,755 mg	19

Source · Chemical formulas and NIH DSLD labels · snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method