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

Magnesium aspartate vs taurate: 1,279–2,670 vs 2,242 mg of compound for 200 mg of magnesium

Magnesium aspartate is 7.5–15.6% elemental magnesium and magnesium taurate is 8.9%, so 200 mg of magnesium needs 1,279–2,670 mg of aspartate against 2,242 mg of taurate: 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 2 for taurate. Prices within each salt: no ranked aspartate price; taurate from $0.1033 per 100 mg (median $0.1842, 4 ranked offers); 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
taurate for 200 mg Mg2,242 mg8.9% magnesium · 4 size 00
Exceeds size 0000 of 15 · 0 of 2aspartate · taurate capsule labels
Cheapest by declared elemental magnesium, per 100 mg, within each saltaspartate none · taurate $0.10330 and 4 ranked offers · 2026-11-02
dumbbell · aspartate vs taurate · compound mass for 100, 200 and 400 mg magnesium, 1,279–2,670 vs 2,242 mg at 200 mg · chemistry 2026-08-10
Compound mass for the same elemental magnesium: dark dot aspartate (7.5–15.6%, lower mass bound), grey dot taurate (8.9%); 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 · taurate 1,121
200 mg magnesium
aspartate 1,279–2,670 · taurate 2,242
400 mg magnesium
aspartate 2,558–5,340 · taurate 4,484

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 taurate carries the same elemental magnesium?

At the same elemental amount, aspartate (7.5–15.6% magnesium) always needs less compound than taurate (8.9%): for 400 mg of magnesium, 2,558–5,340 mg against 4,484 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 taurate
Elemental magnesiumaspartate compoundaspartate size 00taurate compoundtaurate size 00
100 mg639–1,335 mg1–21,121 mg2
200 mg1,279–2,670 mg2–42,242 mg4
400 mg2,558–5,340 mg4–84,484 mg7

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 2 for taurate. 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 taurate · capsule verdicts, 0 of 15 vs 0 of 2 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
taurate
fits 0 of 2
needs 000 2 of 2
exceeds 0 of 2
Capsule verdicts for aspartate and taurate labels
SaltAudited capsule labelsFits 0 or 00Needs 000Exceeds 000
aspartate151320
taurate2020

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; taurate from $0.1033 per 100 mg (median $0.1842, 4 ranked offers). 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
SaltRanked offersLowest per 100 mgMedian per 100 mgObserved
aspartate0nonenone2026-11-02
taurate4$0.1033$0.18422026-11-02

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 taurate side by side?

No study in the PubMed-checked registry measured aspartate and taurate side by side as of 2026-08-10; 2 involve aspartate and 1 involve taurate separately.

measured
Registry studies involving aspartate or taurate
YearStudySalts measuredPubMed
2005Study of magnesium bioavailability from ten organic and inorganic Mg salts in Mg-depleted rats using a stable isotope approachoxide, chloride, sulfate, carbonate, citrate, gluconate, lactate, aspartate, glycinate16548135
2001Bioavailability of US commercial magnesium preparationsoxide, chloride, lactate, aspartate11794633
2019Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best?sulfate, oxide, taurate, citrate, malate29679349

Source · PubMed-checked study registry · registry checked 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method

How many labels name both aspartate and taurate?

No label names both aspartate and taurate as of 2026-08-10, against 46 labels naming aspartate and 12 naming taurate.

measured
Labels naming both salts
LabelDeclared elemental per servingNIH 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 magnesiumaspartate compoundaspartate size 00taurate compoundtaurate size 00
25 mg160–334 mg1280 mg1
50 mg320–668 mg1561 mg1
75 mg480–1,001 mg1–2841 mg2
100 mg639–1,335 mg1–21,121 mg2
125 mg799–1,669 mg2–31,401 mg2
150 mg959–2,003 mg2–31,682 mg3
175 mg1,119–2,336 mg2–41,962 mg3
200 mg1,279–2,670 mg2–42,242 mg4
32 additional rows
Compound mass reference, 25 to 1,000 mg of elemental magnesium, additional rows
Elemental magnesiumaspartate compoundaspartate size 00taurate compoundtaurate size 00
225 mg1,439–3,004 mg2–52,522 mg4
250 mg1,598–3,338 mg3–52,803 mg4
275 mg1,758–3,672 mg3–63,083 mg5
300 mg1,918–4,005 mg3–63,363 mg5
325 mg2,078–4,339 mg3–63,643 mg5
350 mg2,238–4,673 mg4–73,924 mg6
375 mg2,398–5,007 mg4–74,204 mg6
400 mg2,558–5,340 mg4–84,484 mg7
425 mg2,717–5,674 mg4–84,765 mg7
450 mg2,877–6,008 mg4–95,045 mg7
475 mg3,037–6,342 mg5–95,325 mg8
500 mg3,197–6,676 mg5–105,605 mg8
525 mg3,357–7,009 mg5–105,886 mg9
550 mg3,517–7,343 mg5–116,166 mg9
575 mg3,676–7,677 mg6–116,446 mg9
600 mg3,836–8,011 mg6–116,726 mg10
625 mg3,996–8,344 mg6–127,007 mg10
650 mg4,156–8,678 mg6–127,287 mg10
675 mg4,316–9,012 mg6–137,567 mg11
700 mg4,476–9,346 mg7–137,848 mg11
725 mg4,636–9,680 mg7–148,128 mg12
750 mg4,795–10,013 mg7–148,408 mg12
775 mg4,955–10,347 mg7–158,688 mg12
800 mg5,115–10,681 mg8–158,969 mg13
825 mg5,275–11,015 mg8–169,249 mg13
850 mg5,435–11,348 mg8–169,529 mg14
875 mg5,595–11,682 mg8–179,809 mg14
900 mg5,754–12,016 mg8–1710,090 mg14
925 mg5,914–12,350 mg9–1710,370 mg15
950 mg6,074–12,684 mg9–1810,650 mg15
975 mg6,234–13,017 mg9–1810,930 mg15
1,000 mg6,394–13,351 mg9–1911,211 mg16

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