ElementalDose

Equal elemental amount · snapshot 2026-08-10

Magnesium aspartate vs Magnesium oxide

For 200 mg elemental magnesium, magnesium aspartate requires 1,279–2,670 mg of compound and magnesium oxide requires 332 mg, using the chemistry accompanying the 2026-08-10 label snapshot. This difference follows from the magnesium fraction of each compound. It requires no absorption-study assumption: the same elemental mass travels with a different mass of the rest of the compound.

Show the working

Same elemental amount, different compound mass

At 100, 200 and 400 mg elemental magnesium, the chemistry accompanying the 2026-08-10 snapshot uses 7.49–15.64% magnesium by mass for magnesium aspartate and 60.32% for magnesium oxide; dividing the elemental amount by these fractions gives the compound masses below.

Formula, magnesium fraction and compound mass · snapshot context 2026-08-10
PropertyMagnesium aspartateMagnesium oxide
Elemental Mg by compound mass7.49–15.64%60.32%
Anhydrous reference formulaMgC₄H₅NO₄MgO
Molar mass of that reference formula155.39 g/mol40.30 g/mol
Composition interval1:1 magnesium aspartate 15.64%; bis(hydrogen aspartate) 8.42%, its dihydrate 7.49%; stoichiometry and hydration unresolvedOne formula fraction used for MgO in this model.
Compound for 100 mg elemental Mg639–1,335 mg166 mg
Compound for 200 mg elemental Mg1,279–2,670 mg332 mg
Compound for 400 mg elemental Mg2,558–5,340 mg663 mg
Size 00 capsules for 100 mg elemental Mg1–2 capsules at 730 mg compound fill each1 capsules at 730 mg compound fill each
Size 00 capsules for 200 mg elemental Mg2–4 capsules at 730 mg compound fill each1 capsules at 730 mg compound fill each
Size 00 capsules for 400 mg elemental Mg4–8 capsules at 730 mg compound fill each1 capsules at 730 mg compound fill each

Molar masses refer to the displayed anhydrous formulas. Hydrated or composition-ambiguous readings use the full fraction interval from the chemistry layer. Compound masses are rounded to whole milligrams; capsule counts round the unrounded mass divided by 730 mg upward at each interval endpoint.

Magnesium aspartate: 200 mg worked example

For 200 mg elemental magnesium as magnesium aspartate, the chemistry accompanying the 2026-08-10 snapshot requires 1,279–2,670 mg of compound: 200 ÷ 0.1564 through 200 ÷ 0.0749, rounded to whole milligrams.

That requires 2–4 size 00 capsules at 730 mg of compound per capsule, before other ingredients. The mass interval reflects 1:1 magnesium aspartate 15.64%; bis(hydrogen aspartate) 8.42%, its dihydrate 7.49%; stoichiometry and hydration unresolved.

Magnesium oxide: 200 mg worked example

For 200 mg elemental magnesium as magnesium oxide, the chemistry accompanying the 2026-08-10 snapshot requires 332 mg of compound: 200 ÷ 0.6032, rounded to whole milligrams.

That requires 1 size 00 capsules at 730 mg of compound per capsule, before other ingredients. The model uses the MgO fraction throughout.

Compound mass reference in 25 mg elemental increments

40 arithmetic inputs from 25 to 1,000 mg elemental magnesium are converted below using the two salt fractions and the capsule capacities accompanying the 2026-08-10 snapshot, calculated 2026-10-17. These are mass-conversion inputs, independent of any consumption schedule.

Each compound interval divides the elemental input by the high and low magnesium fractions. Each capsule interval divides those unrounded compound masses by the listed fill capacity, then rounds upward. The three capsule sizes use 545, 730 and 1100 mg of compound per capsule respectively, before other ingredients.

Magnesium aspartate and Magnesium oxide · 40 elemental inputs · 2026-10-17
Elemental MgMagnesium aspartate: compound massMagnesium aspartate: size 0Magnesium aspartate: size 00Magnesium aspartate: size 000Magnesium oxide: compound massMagnesium oxide: size 0Magnesium oxide: size 00Magnesium oxide: size 000
25 mg elemental Mg160–334 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill41 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
50 mg elemental Mg320–668 mg compound1–2 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill83 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
75 mg elemental Mg480–1,001 mg compound1–2 capsules at 545 mg fill1–2 capsules at 730 mg fill1 capsules at 1100 mg fill124 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
100 mg elemental Mg639–1,335 mg compound2–3 capsules at 545 mg fill1–2 capsules at 730 mg fill1–2 capsules at 1100 mg fill166 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
125 mg elemental Mg799–1,669 mg compound2–4 capsules at 545 mg fill2–3 capsules at 730 mg fill1–2 capsules at 1100 mg fill207 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
150 mg elemental Mg959–2,003 mg compound2–4 capsules at 545 mg fill2–3 capsules at 730 mg fill1–2 capsules at 1100 mg fill249 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
175 mg elemental Mg1,119–2,336 mg compound3–5 capsules at 545 mg fill2–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill290 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
200 mg elemental Mg1,279–2,670 mg compound3–5 capsules at 545 mg fill2–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill332 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
225 mg elemental Mg1,439–3,004 mg compound3–6 capsules at 545 mg fill2–5 capsules at 730 mg fill2–3 capsules at 1100 mg fill373 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
250 mg elemental Mg1,598–3,338 mg compound3–7 capsules at 545 mg fill3–5 capsules at 730 mg fill2–4 capsules at 1100 mg fill414 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
275 mg elemental Mg1,758–3,672 mg compound4–7 capsules at 545 mg fill3–6 capsules at 730 mg fill2–4 capsules at 1100 mg fill456 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
300 mg elemental Mg1,918–4,005 mg compound4–8 capsules at 545 mg fill3–6 capsules at 730 mg fill2–4 capsules at 1100 mg fill497 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
325 mg elemental Mg2,078–4,339 mg compound4–8 capsules at 545 mg fill3–6 capsules at 730 mg fill2–4 capsules at 1100 mg fill539 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
350 mg elemental Mg2,238–4,673 mg compound5–9 capsules at 545 mg fill4–7 capsules at 730 mg fill3–5 capsules at 1100 mg fill580 mg compound2 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
375 mg elemental Mg2,398–5,007 mg compound5–10 capsules at 545 mg fill4–7 capsules at 730 mg fill3–5 capsules at 1100 mg fill622 mg compound2 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
400 mg elemental Mg2,558–5,340 mg compound5–10 capsules at 545 mg fill4–8 capsules at 730 mg fill3–5 capsules at 1100 mg fill663 mg compound2 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
425 mg elemental Mg2,717–5,674 mg compound5–11 capsules at 545 mg fill4–8 capsules at 730 mg fill3–6 capsules at 1100 mg fill705 mg compound2 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
450 mg elemental Mg2,877–6,008 mg compound6–12 capsules at 545 mg fill4–9 capsules at 730 mg fill3–6 capsules at 1100 mg fill746 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
475 mg elemental Mg3,037–6,342 mg compound6–12 capsules at 545 mg fill5–9 capsules at 730 mg fill3–6 capsules at 1100 mg fill787 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
500 mg elemental Mg3,197–6,676 mg compound6–13 capsules at 545 mg fill5–10 capsules at 730 mg fill3–7 capsules at 1100 mg fill829 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
525 mg elemental Mg3,357–7,009 mg compound7–13 capsules at 545 mg fill5–10 capsules at 730 mg fill4–7 capsules at 1100 mg fill870 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
550 mg elemental Mg3,517–7,343 mg compound7–14 capsules at 545 mg fill5–11 capsules at 730 mg fill4–7 capsules at 1100 mg fill912 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
575 mg elemental Mg3,676–7,677 mg compound7–15 capsules at 545 mg fill6–11 capsules at 730 mg fill4–7 capsules at 1100 mg fill953 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
600 mg elemental Mg3,836–8,011 mg compound8–15 capsules at 545 mg fill6–11 capsules at 730 mg fill4–8 capsules at 1100 mg fill995 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
625 mg elemental Mg3,996–8,344 mg compound8–16 capsules at 545 mg fill6–12 capsules at 730 mg fill4–8 capsules at 1100 mg fill1,036 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
650 mg elemental Mg4,156–8,678 mg compound8–16 capsules at 545 mg fill6–12 capsules at 730 mg fill4–8 capsules at 1100 mg fill1,078 mg compound2 capsules at 545 mg fill2 capsules at 730 mg fill1 capsules at 1100 mg fill
675 mg elemental Mg4,316–9,012 mg compound8–17 capsules at 545 mg fill6–13 capsules at 730 mg fill4–9 capsules at 1100 mg fill1,119 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
700 mg elemental Mg4,476–9,346 mg compound9–18 capsules at 545 mg fill7–13 capsules at 730 mg fill5–9 capsules at 1100 mg fill1,160 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
725 mg elemental Mg4,636–9,680 mg compound9–18 capsules at 545 mg fill7–14 capsules at 730 mg fill5–9 capsules at 1100 mg fill1,202 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
750 mg elemental Mg4,795–10,013 mg compound9–19 capsules at 545 mg fill7–14 capsules at 730 mg fill5–10 capsules at 1100 mg fill1,243 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
775 mg elemental Mg4,955–10,347 mg compound10–19 capsules at 545 mg fill7–15 capsules at 730 mg fill5–10 capsules at 1100 mg fill1,285 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
800 mg elemental Mg5,115–10,681 mg compound10–20 capsules at 545 mg fill8–15 capsules at 730 mg fill5–10 capsules at 1100 mg fill1,326 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
825 mg elemental Mg5,275–11,015 mg compound10–21 capsules at 545 mg fill8–16 capsules at 730 mg fill5–11 capsules at 1100 mg fill1,368 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
850 mg elemental Mg5,435–11,348 mg compound10–21 capsules at 545 mg fill8–16 capsules at 730 mg fill5–11 capsules at 1100 mg fill1,409 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
875 mg elemental Mg5,595–11,682 mg compound11–22 capsules at 545 mg fill8–17 capsules at 730 mg fill6–11 capsules at 1100 mg fill1,451 mg compound3 capsules at 545 mg fill2 capsules at 730 mg fill2 capsules at 1100 mg fill
900 mg elemental Mg5,754–12,016 mg compound11–23 capsules at 545 mg fill8–17 capsules at 730 mg fill6–11 capsules at 1100 mg fill1,492 mg compound3 capsules at 545 mg fill3 capsules at 730 mg fill2 capsules at 1100 mg fill
925 mg elemental Mg5,914–12,350 mg compound11–23 capsules at 545 mg fill9–17 capsules at 730 mg fill6–12 capsules at 1100 mg fill1,533 mg compound3 capsules at 545 mg fill3 capsules at 730 mg fill2 capsules at 1100 mg fill
950 mg elemental Mg6,074–12,684 mg compound12–24 capsules at 545 mg fill9–18 capsules at 730 mg fill6–12 capsules at 1100 mg fill1,575 mg compound3 capsules at 545 mg fill3 capsules at 730 mg fill2 capsules at 1100 mg fill
975 mg elemental Mg6,234–13,017 mg compound12–24 capsules at 545 mg fill9–18 capsules at 730 mg fill6–12 capsules at 1100 mg fill1,616 mg compound3 capsules at 545 mg fill3 capsules at 730 mg fill2 capsules at 1100 mg fill
1000 mg elemental Mg6,394–13,351 mg compound12–25 capsules at 545 mg fill9–19 capsules at 730 mg fill6–13 capsules at 1100 mg fill1,658 mg compound4 capsules at 545 mg fill3 capsules at 730 mg fill2 capsules at 1100 mg fill

A whole capsule count describes the minimum number of modelled containers needed to hold compound mass. It does not establish the dimensions, packing density or excipient content of a retail product. The ingredient list and serving statement on each linked record supply the product-specific context.

Declarations against capacity

How each salt's capsule labels distribute

In the 2026-08-10 snapshot, the magnesium aspartate form group has 15 audited capsule labels and the magnesium oxide group has 12; their distributions below use the mass-budget counts stored for each form, at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range.

Capsule mass budgets within each form group · 2026-08-10
Salt groupAll labelsAudited capsulesFits 0/00Needs 000Exceeds 000
Magnesium aspartate46151320
Magnesium oxide124121110

At 2026-08-10, magnesium aspartate has 13 of 15 audited capsule labels at or below 730 mg minimum compound mass per capsule, 2 above 730 mg but at or below 1100 mg, and 0 above 1100 mg. Its other 31 labels have no capsule verdict in this group, either because they are not classified as capsules or because a mass budget is unavailable.

At 2026-08-10, magnesium oxide has 11 of 12 audited capsule labels at or below 730 mg minimum compound mass per capsule, 1 above 730 mg but at or below 1100 mg, and 0 above 1100 mg. Its other 112 labels have no capsule verdict in this group, either because they are not classified as capsules or because a mass budget is unavailable.

The audit divides a label's elemental amount by its assigned salt fraction and serving-unit count. It uses the highest fraction, hence the smallest required mass. A hydration interval can move a nominally fitting label into a larger size at its high-mass end. A result exceeding 000 means the assigned single salt exceeds this fill model even at the low-mass end.

Form groups include names in extracted primary rows, resolved salts and full-record salt mentions, and can overlap; a capsule verdict requires a single assigned salt matching this group. These are counts of label declarations, with the capsule model allocating the fill to the compound. Inspect individual serving statements and assigned salts in the audit register and the linked form pages.

Literature coverage

Which measurements are attached to these salts?

As of the literature review dated 2026-09-11, the supplied study collection associates 2 publications with magnesium aspartate and 12 with magnesium oxide; the combined list contains 12 unique publications, with shared records printed once.

Study-set membership · reviewed 2026-09-11
SaltPublicationsPublication years
Magnesium aspartate22001–2005
Magnesium oxide121990–2026

Membership means that at least one selected salt appears in the study's recorded coverage; it does not mean every paper directly compares this exact pair. In particular, an amino-acid-chelate arm does not establish a chemically defined bisglycinate preparation. Each record below retains its actual design, population, read-out and limits.

Published measurements · peer-reviewed sources

12 published measurements relevant to this pair

The 2026-09-11 literature review links these 12 publications, ordered newest first; study outcomes remain attached to their own experimental conditions.

These entries report what each study measured and on whom. They are not advice, not a ranking, and not a claim about any product on this site. Every reference links to its PubMed record so the original can be read in full.

  1. Randomized, open-label study of the short-term pharmacokinetics of oral magnesium oxide in healthy volunteers.

    Scientific reports · 2026 · PMID 42091979

    Design
    Randomized, open-label pharmacokinetic study in 24 healthy male volunteers aged 18-45 years, equally assigned to a single oral dose of either 750 mg or 2000 mg magnesium oxide.
    What it measured
    Serum magnesium concentrations at baseline and multiple time points up to 12 hours post-dose (colorimetric assay); pharmacokinetic parameters Cmax, Tmax, and AUC0-12 via non-compartmental analysis; safety via vital signs, laboratory parameters, ECG, and adverse events.
    Limits
    Male volunteers only, no female data; only two dose levels tested (750 mg, 2000 mg) so dose-proportionality across a wider range is not established; terminal elimination parameters (t1/2, AUC0-infinity, CL/F, MRT) could not be estimated within the 12-hour sampling window; single-dose (not chronic) administration; sample size n=24 (12 per dose group).

  2. Comparative Clinical Study on Magnesium Absorption and Side Effects After Oral Intake of Microencapsulated Magnesium (MAGSHAPE™ Microcapsules) Versus Other Magnesium Sources.

    Nutrients · 2024 · PMID 39770988

    Design
    Double-blind, randomized, cross-over clinical study in 40 healthy women and men. Participants followed a low-magnesium diet for 7 days and fasted 8 hours, then received a single oral dose of each of four products in cross-over fashion: microencapsulated magnesium (Mg-MS / MAGSHAPE), magnesium oxide (MgO), magnesium citrate (Mg-C), and magnesium bisglycinate (Mg-BG). Blood was drawn by digital puncture before dosing (0 h) and at 1, 4, and 6 hours after each product.
    What it measured
    Plasma magnesium concentration at 0, 1, 4, and 6 hours after oral intake of each of the four products; gastrointestinal side effects (intestinal motility, sensations of gastric heaviness) associated with each product.
    Limits
    Single-dose exposure per product, not chronic supplementation; sample size n=40; a specific proprietary microencapsulation technology was tested, which may not generalize to other encapsulation methods; plasma magnesium was the only absorption marker used (no urinary or tissue measurement).

  3. Effects of short-term magnesium supplementation on ionized, total magnesium and other relevant electrolytes levels.

    Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine · 2022 · PMID 35041150

    Design
    Short-term, 10-day supplementation study in 61 healthy young female adults, comparing three magnesium supplement forms: magnesium oxide (powder/granulate), magnesium citrate, and magnesium carbonate (effervescent tablets).
    What it measured
    Ionized magnesium concentration and its percentage of total magnesium; serum total magnesium concentration; other serum electrolyte levels — each assessed at baseline and after the 10-day intervention.
    Limits
    Healthy young female adults only, no male or older/deficient populations studied; short 10-day intervention with no longer-term follow-up; three specific product formulations were tested, so results may not generalize to other products of the same salts; the abstract does not report the per-arm breakdown of the 61 participants.

  4. Dose-Dependent Absorption Profile of Different Magnesium Compounds

    Biological Trace Element Research · 2020 · PMID 30761462

    Design
    Absorption of several magnesium compounds profiled across doses rather than at a single dose.
    What it measured
    Absorption is treated as dose-dependent, so a comparison made at one dose need not hold at another — which is why single-dose head-to-head results disagree.
    Limits
    Compound coverage and sample size vary by arm; read the paper before carrying any single figure across.

  5. Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best?

    Biological trace element research · 2019 · PMID 29679349

    Design
    Single-dose administration of 400 mg/70 kg magnesium as one of five compounds (magnesium sulfate, magnesium oxide, magnesium acetyl taurate, magnesium citrate, magnesium malate) to Sprague Dawley rats, with a control group, followed by time-dependent tissue and serum sampling.
    What it measured
    Time-dependent magnesium absorption profile (area under the curve) in serum; magnesium tissue penetration and concentration, including brain tissue; behavioral indicators (e.g., anxiety-related behavior) recorded in the animals.
    Limits
    Animal model (Sprague Dawley rats), not humans — extrapolation of pharmacokinetic and behavioral findings to people is not established; single dose only, no chronic-dosing data; per-compound group sample size is not stated in the abstract; behavioral endpoints were measured only in rodents. The tested acetyl taurate is distinct from the unmodified taurate in the chemistry table.

  6. Comparison of magnesium status using X-ray dispersion analysis following magnesium oxide and magnesium citrate treatment of healthy subjects

    Magnesium Research · 2012 · PMID 22433473

    Design
    Oral magnesium citrate versus magnesium oxide in healthy subjects; intracellular magnesium measured by X-ray dispersion analysis, alongside platelet function.
    What it measured
    The comparison used intracellular magnesium rather than serum magnesium, which changes what the read-out means.
    Limits
    Healthy subjects, small sample; intracellular magnesium by X-ray dispersion is not a routine clinical measure.

  7. Study of magnesium bioavailability from ten organic and inorganic Mg salts in Mg-depleted rats using a stable isotope approach

    Magnesium Research · 2005 · PMID 16548135

    Design
    Eighty male Wistar rats fed a magnesium-depleted diet for three weeks, then randomised into ten groups, each receiving a different magnesium salt labelled with a stable isotope.
    What it measured
    Stable isotopes allow absorption and retention to be traced directly rather than inferred from urine, across ten salts at once — the widest head-to-head comparison in the literature.
    Limits
    Rats, not people, and magnesium-depleted rats at that: depletion itself raises absorption. The breadth of the comparison is its value; the species is its limit.

  8. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study

    Magnesium Research · 2003 · PMID 14596323

    Design
    Randomised, double-blind, placebo-controlled parallel study in 46 healthy individuals, 300 mg of elemental magnesium per day, comparing an amino-acid chelate, citrate and oxide.
    What it measured
    Relative bioavailability of the three preparations was compared at an equal elemental dose.
    Limits
    46 participants, healthy, 300 mg per day; “amino-acid chelate” is a class rather than one defined compound, so the chelate arm is not a single substance.

  9. Bioavailability of US commercial magnesium preparations

    Magnesium Research · 2001 · PMID 11794633

    Design
    Four commercially available US preparations given to healthy volunteers; bioavailability measured as the increment in urinary magnesium excretion.
    What it measured
    The study set out to test the claim that organic magnesium salts are more easily absorbed than inorganic ones, using urinary excretion as the read-out.
    Limits
    Healthy volunteers, small sample, urinary excretion as a proxy for absorption rather than a direct measurement of retention.

  10. Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection

    JPEN: Journal of Parenteral and Enteral Nutrition · 1995 · PMID 7815675

    Design
    Comparison of magnesium diglycinate (a chelate) with magnesium oxide in patients who had undergone ileal resection.
    What it measured
    The work followed in vitro and in situ findings suggesting diglycinate is absorbed by a different route than inorganic salts, and tested that in patients with impaired absorption.
    Limits
    Patients after ileal resection are a specific clinical population with poor absorption to begin with; results do not transfer to people with an intact gut.

  11. Magnesium bioavailability from magnesium citrate and magnesium oxide

    Journal of the American College of Nutrition · 1990 · PMID 2407766

    Design
    In vitro solubility of 25 mmol of each salt across hydrochloric acid concentrations mimicking achlorhydric to peak acid secretion, plus in vivo gastrointestinal absorbability.
    What it measured
    Magnesium oxide was virtually insoluble across the acid range tested, while citrate dissolved; absorbability was then compared in vivo.
    Limits
    Solubility in a beaker is not absorption in a person; the in vivo arm is small. Published 1990.

  12. Effect of magnesium citrate and magnesium oxide on the crystallization of calcium salts in urine

    The Journal of Urology · 1990 · PMID 2299712

    Design
    Seven normal subjects and four patients with recurrent calcium oxalate stones; 486 mg of magnesium per day for two weeks, taken on an empty stomach and again with food.
    What it measured
    Taken on an empty stomach, urinary magnesium rose by only 77–79 mg per day out of 486 mg given — and the increase changed when the dose was taken with food.
    Limits
    Eleven subjects; the endpoint is urinary chemistry in stone formers, not absorption in general. Published 1990.

Magnesium aspartate: trace the filed inputs

8 of 46 labels mentioning magnesium aspartate are shown in brand order from the supplied NIH DSLD records, calculated 2026-10-17. Salt mentions can overlap; only records assigned this single salt enter its capsule audit above.

Filed labels in brand and product order · 8 labels · calculated 2026-10-17
Brand / labelSalt / physical stateFiled servingObserved item price / EC100
Adaptogen Research Potassium MagnesiumNIH DSLD 247239 · label 2021-05-22Single salt unresolved as of 2026-10-17Tablet or Pill1 Tablet(s)100 mg elemental magnesium per servingNo published price matched to barcode 8 28054 77273 1 as of 2026-10-17.
AOR Advanced Orthomolecular Research Advanced Advanced Magnesium ComplexNIH DSLD 214423 · label 2020-02-26Single salt unresolved as of 2026-10-17Capsule1 Capsule(s)Elemental amount unresolved as of 2026-10-17No published price matched to barcode 6 24917 08333 0 as of 2026-10-17.
AOR Advanced Orthomolecular Research Premium Magnesium Potassium AspartatesNIH DSLD 214686 · label 2020-03-24Magnesium aspartateCapsule1 Capsule(s)Elemental amount unresolved as of 2026-10-17No published price matched to barcode 6 2497 08224 1 as of 2026-10-17.
BIOVEA Magnesium 200 mgNIH DSLD 249072 · label 2021-05-22Single salt unresolved as of 2026-10-17Capsule1 Vegetarian Capsule(s)200 mg elemental magnesium per servingNo published price matched to barcode 8 11079 03132 7 as of 2026-10-17.
Bronson Potassium & Magnesium AspartateNIH DSLD 9135 · label 2012-06-01Magnesium aspartateCapsule1 Capsule(s)21 mg elemental magnesium per servingNo published price matched to barcode 7 16563 25101 7 as of 2026-10-17.
BulkSupplements.com Magnesium D-AspartateNIH DSLD 310740 · label 2024-03-22Magnesium aspartatePowder680 mg (about 1/4 tsp)49 mg elemental magnesium per serving$35.97 per container; cost per 100 mg not computedObserved 2026-09-11 · provisional (pack weight differs: the offer lists 250 g, the label 1000 g)
BulkSupplements.com Magnesium D-AspartateNIH DSLD 310742 · label 2024-03-22Magnesium aspartatePowder680 mg (about 1/4 tsp)49 mg elemental magnesium per servingNo published price matched to barcode X00191LG7V as of 2026-10-17.
BulkSupplements.com Magnesium D-AspartateNIH DSLD 310743 · label 2024-03-22Magnesium aspartatePowder680 mg (about 1/4 tsp)49 mg elemental magnesium per servingNo published price matched to barcode X0018VO6HJ as of 2026-10-17.

Open the salt index and linked records to inspect ingredient lists, the source of the assigned salt and dated gaps in price matching.

Magnesium oxide: trace the filed inputs

8 of 124 labels mentioning magnesium oxide are shown in brand order from the supplied NIH DSLD records, calculated 2026-10-17. Salt mentions can overlap; only records assigned this single salt enter its capsule audit above.

Filed labels in brand and product order · 8 labels · calculated 2026-10-17
Brand / labelSalt / physical stateFiled servingObserved item price / EC100
Adaptogen Research Magnesium Buffered ChelateNIH DSLD 247097 · label 2021-05-22Single salt unresolved as of 2026-10-17Capsule2 Capsule(s)300 mg elemental magnesium per servingNo published price matched to barcode 688907 859794 as of 2026-10-17.
Adaptogen Research Magnesium Buffered ChelateNIH DSLD 247098 · label 2021-05-22Single salt unresolved as of 2026-10-17Capsule2 Capsule(s)300 mg elemental magnesium per servingNo published price matched to barcode 688907 859800 as of 2026-10-17.
Approved Science Magnesium ComplexNIH DSLD 319784 · label 2024-11-22Single salt unresolved as of 2026-10-17Capsule1 Capsule(s)Elemental amount unresolved as of 2026-10-17No published price matched to barcode X0039PGF67 as of 2026-10-17.
AvalonX Powered by MDLogic Magnesium 8NIH DSLD 299138 · label 2023-11-22Single salt unresolved as of 2026-10-17Capsule2 Capsule(s)500 mg elemental magnesium per servingNo published price matched to barcode 8 97395 00282 1 as of 2026-10-17.
Basic Vitamins Magnesium 250 mgNIH DSLD 250165 · label 2021-05-22Magnesium oxideTablet or Pill1–2 Tablet(s)250 mg elemental magnesium per servingNo published price matched to barcode 3 07610 28320 6 as of 2026-10-17.
BioSchwartz Magnesium BisglycinateNIH DSLD 228062 · label 2020-06-24Single salt unresolved as of 2026-10-17Capsule2 Capsule(s)72 mg elemental magnesium per servingNo published price matched to NIH DSLD 228062; barcode not filed as of 2026-10-17.
BIOVEA Calcium-MagnesiumNIH DSLD 248974 · label 2021-05-22Single salt unresolved as of 2026-10-17Capsule3 Vegetarian Capsule(s)500 mg elemental magnesium per servingNo published price matched to barcode 8 18423 02124 9 as of 2026-10-17.
BIOVEA Magnesium 200 mgNIH DSLD 249072 · label 2021-05-22Single salt unresolved as of 2026-10-17Capsule1 Vegetarian Capsule(s)200 mg elemental magnesium per servingNo published price matched to barcode 8 11079 03132 7 as of 2026-10-17.

Open the salt index and linked records to inspect ingredient lists, the source of the assigned salt and dated gaps in price matching.

Retail observations · after chemistry and evidence

Price observations within each salt

As of 2026-10-17, the published price set contains 0 verified magnesium aspartate matches and 8 verified magnesium oxide matches. Each table below contains one salt and its own sample size; verified medians describe only that salt's verified rows.

EC100 = container price ÷ (declared elemental mg per serving × servings per container ÷ 100). It normalizes the container's elemental amount. The observations use one-time item prices, without coupons or subscriptions and excluding shipping. The tables retain the two salts' page order; sorting operates inside an individual salt table.

Magnesium aspartate: its own retail sample

As of 2026-10-17, magnesium aspartate has 0 verified matches and 3 pending matches in the price set. No verified median is available as of 2026-10-17. Observation dates: 2026-09-11 to 2026-10-26.

0 verified retail matches are published for magnesium aspartate as of 2026-10-17.

Magnesium aspartate · pending observations · reviewed 2026-10-17 · n= 3

These candidate retail-to-label matches remain separate from verified rows and are not included in verified medians.

Magnesium aspartate · pending observations · reviewed 2026-10-17 · n=
BulkSupplements.comMagnesium D-AspartateNIH DSLD · Label 31074049 mg1,471$35.97Per container · Price observed 2026-09-11, AmazonNot computedpack weight differs: the offer lists 250 g, the label 1000 gPending · provisional
SwansonMagnesium AspartateNIH DSLD · Label 308656133 mg90$14.84Per container · Price observed 2026-09-11, AmazonNot computedthe offer is a multi-pack (2 packs)Pending · provisional
NOWMagnesium & Potassium AspartateNIH DSLD · Label 204986250 mg60$29.62Per container · Price observed 2026-10-26, AmazonNot computedthe offer is a multi-pack (2 packs)Pending · provisional

Open the magnesium aspartate label group →

Magnesium oxide: its own retail sample

As of 2026-10-17, magnesium oxide has 8 verified matches and 2 pending matches in the price set. Its verified EC100 median is $0.0293 per 100 mg elemental magnesium (n=8); pending matches are excluded from that median. Observation dates: 2026-09-11 to 2026-11-02.

Magnesium oxide · verified observations · reviewed 2026-10-17 · n= 8

Magnesium oxide · verified observations · reviewed 2026-10-17 · n=
CarlsonMagnesium Gels 400 mgNIH DSLD · Label 216334400 mg100$25.42Per container · Price observed 2026-11-02, Amazon$0.063640.00 total elemental g/containerVerified
Wonder LabsMagnesium Oxide 400NIH DSLD · Label 261002482.6 mg125$21.49Per container · Price observed 2026-11-02, Amazon$0.035660.33 total elemental g/containerVerified
Wonder LabsMagnesium Oxide 400NIH DSLD · Label 262919482.6 mg125$21.49Per container · Price observed 2026-11-02, Amazon$0.035660.33 total elemental g/containerVerified
Wonder LabsMagnesium Oxide 400NIH DSLD · Label 316129482.6 mg125$21.49Per container · Price observed 2026-11-02, Amazon$0.035660.33 total elemental g/containerVerified
NutricostMagnesium Oxide 375 mgNIH DSLD · Label 270606210 mg240$14.95Per container · Price observed 2026-11-02, Amazon$0.029750.40 total elemental g/containerVerified
NutricostMagnesium OxideNIH DSLD · Label 223424420 mg240$14.95Per container · Price observed 2026-11-02, Amazon$0.0148100.80 total elemental g/containerVerified
tnvitaminsMagnesium Oxide 420 mgNIH DSLD · Label 336940420 mg120$12.99Per container · Price observed 2026-11-02, Amazon$0.025850.40 total elemental g/containerVerified
Douglas LaboratoriesMagnesium OxideNIH DSLD · Label 245309300 mg250$22.00Per container · Price observed 2026-11-02, Amazon$0.029375.00 total elemental g/containerVerified
Magnesium oxide · pending observations · reviewed 2026-10-17 · n= 2

These candidate retail-to-label matches remain separate from verified rows and are not included in verified medians.

Magnesium oxide · pending observations · reviewed 2026-10-17 · n=
BulkSupplements.comMagnesium Oxide PowderNIH DSLD · Label 329720500 mg599$17.97Per container · Price observed 2026-09-11, AmazonNot computedpack weight differs: the offer lists 250 g, the label 500 gPending · provisional
NusaPureMagnesium Oxide 1000 mgNIH DSLD · Label 2749631,000 mg90$19.35Per container · Price observed 2026-09-21, AmazonNot computedthe filed elemental amount (1000 mg per serving) is likely the compound massPending · provisional

Open the magnesium oxide label group →

To reproduce a container calculation, use the elemental cost calculator and its static mass tables. The magnesium collection abstract connects each salt group to the label corpus; the literature collection puts the cited measurements in their broader study context.