ElementalDose

Equal elemental amount · snapshot 2026-08-10

Magnesium citrate vs Magnesium sulfate

For 200 mg elemental magnesium, magnesium citrate requires 1,238–1,770 mg of compound and magnesium sulfate requires 991–2,028 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 11.30–16.16% magnesium by mass for magnesium citrate and 9.86–20.19% for magnesium sulfate; dividing the elemental amount by these fractions gives the compound masses below.

Formula, magnesium fraction and compound mass · snapshot context 2026-08-10
PropertyMagnesium citrateMagnesium sulfate
Elemental Mg by compound mass11.30–16.16%9.86–20.19%
Anhydrous reference formulaMg₃(C₆H₅O₇)₂MgSO₄
Molar mass of that reference formula451.11 g/mol120.37 g/mol
Composition intervaltrimagnesium dicitrate 16.2%; dibasic and hydrated forms as low as 11.3%anhydrous 20.2%, heptahydrate 9.9%
Compound for 100 mg elemental Mg619–885 mg495–1,014 mg
Compound for 200 mg elemental Mg1,238–1,770 mg991–2,028 mg
Compound for 400 mg elemental Mg2,475–3,540 mg1,981–4,057 mg
Size 00 capsules for 100 mg elemental Mg1–2 capsules at 730 mg compound fill each1–2 capsules at 730 mg compound fill each
Size 00 capsules for 200 mg elemental Mg2–3 capsules at 730 mg compound fill each2–3 capsules at 730 mg compound fill each
Size 00 capsules for 400 mg elemental Mg4–5 capsules at 730 mg compound fill each3–6 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 citrate: 200 mg worked example

For 200 mg elemental magnesium as magnesium citrate, the chemistry accompanying the 2026-08-10 snapshot requires 1,238–1,770 mg of compound: 200 ÷ 0.1616 through 200 ÷ 0.1130, rounded to whole milligrams.

That requires 2–3 size 00 capsules at 730 mg of compound per capsule, before other ingredients. The mass interval reflects trimagnesium dicitrate 16.2%; dibasic and hydrated forms as low as 11.3%.

Magnesium sulfate: 200 mg worked example

For 200 mg elemental magnesium as magnesium sulfate, the chemistry accompanying the 2026-08-10 snapshot requires 991–2,028 mg of compound: 200 ÷ 0.2019 through 200 ÷ 0.0986, rounded to whole milligrams.

That requires 2–3 size 00 capsules at 730 mg of compound per capsule, before other ingredients. The mass interval reflects anhydrous 20.2%, heptahydrate 9.9%.

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 2026-09-13. 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 citrate and Magnesium sulfate · 40 elemental inputs · 2026-09-13
Elemental MgMagnesium citrate: compound massMagnesium citrate: size 0Magnesium citrate: size 00Magnesium citrate: size 000Magnesium sulfate: compound massMagnesium sulfate: size 0Magnesium sulfate: size 00Magnesium sulfate: size 000
25 mg elemental Mg155–221 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill124–254 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
50 mg elemental Mg309–442 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill248–507 mg compound1 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill
75 mg elemental Mg464–664 mg compound1–2 capsules at 545 mg fill1 capsules at 730 mg fill1 capsules at 1100 mg fill371–761 mg compound1–2 capsules at 545 mg fill1–2 capsules at 730 mg fill1 capsules at 1100 mg fill
100 mg elemental Mg619–885 mg compound2 capsules at 545 mg fill1–2 capsules at 730 mg fill1 capsules at 1100 mg fill495–1,014 mg compound1–2 capsules at 545 mg fill1–2 capsules at 730 mg fill1 capsules at 1100 mg fill
125 mg elemental Mg774–1,106 mg compound2–3 capsules at 545 mg fill2 capsules at 730 mg fill1–2 capsules at 1100 mg fill619–1,268 mg compound2–3 capsules at 545 mg fill1–2 capsules at 730 mg fill1–2 capsules at 1100 mg fill
150 mg elemental Mg928–1,327 mg compound2–3 capsules at 545 mg fill2 capsules at 730 mg fill1–2 capsules at 1100 mg fill743–1,521 mg compound2–3 capsules at 545 mg fill2–3 capsules at 730 mg fill1–2 capsules at 1100 mg fill
175 mg elemental Mg1,083–1,549 mg compound2–3 capsules at 545 mg fill2–3 capsules at 730 mg fill1–2 capsules at 1100 mg fill867–1,775 mg compound2–4 capsules at 545 mg fill2–3 capsules at 730 mg fill1–2 capsules at 1100 mg fill
200 mg elemental Mg1,238–1,770 mg compound3–4 capsules at 545 mg fill2–3 capsules at 730 mg fill2 capsules at 1100 mg fill991–2,028 mg compound2–4 capsules at 545 mg fill2–3 capsules at 730 mg fill1–2 capsules at 1100 mg fill
225 mg elemental Mg1,392–1,991 mg compound3–4 capsules at 545 mg fill2–3 capsules at 730 mg fill2 capsules at 1100 mg fill1,114–2,282 mg compound3–5 capsules at 545 mg fill2–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill
250 mg elemental Mg1,547–2,212 mg compound3–5 capsules at 545 mg fill3–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill1,238–2,535 mg compound3–5 capsules at 545 mg fill2–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill
275 mg elemental Mg1,702–2,434 mg compound4–5 capsules at 545 mg fill3–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill1,362–2,789 mg compound3–6 capsules at 545 mg fill2–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill
300 mg elemental Mg1,856–2,655 mg compound4–5 capsules at 545 mg fill3–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill1,486–3,043 mg compound3–6 capsules at 545 mg fill3–5 capsules at 730 mg fill2–3 capsules at 1100 mg fill
325 mg elemental Mg2,011–2,876 mg compound4–6 capsules at 545 mg fill3–4 capsules at 730 mg fill2–3 capsules at 1100 mg fill1,610–3,296 mg compound3–7 capsules at 545 mg fill3–5 capsules at 730 mg fill2–3 capsules at 1100 mg fill
350 mg elemental Mg2,166–3,097 mg compound4–6 capsules at 545 mg fill3–5 capsules at 730 mg fill2–3 capsules at 1100 mg fill1,734–3,550 mg compound4–7 capsules at 545 mg fill3–5 capsules at 730 mg fill2–4 capsules at 1100 mg fill
375 mg elemental Mg2,321–3,319 mg compound5–7 capsules at 545 mg fill4–5 capsules at 730 mg fill3–4 capsules at 1100 mg fill1,857–3,803 mg compound4–7 capsules at 545 mg fill3–6 capsules at 730 mg fill2–4 capsules at 1100 mg fill
400 mg elemental Mg2,475–3,540 mg compound5–7 capsules at 545 mg fill4–5 capsules at 730 mg fill3–4 capsules at 1100 mg fill1,981–4,057 mg compound4–8 capsules at 545 mg fill3–6 capsules at 730 mg fill2–4 capsules at 1100 mg fill
425 mg elemental Mg2,630–3,761 mg compound5–7 capsules at 545 mg fill4–6 capsules at 730 mg fill3–4 capsules at 1100 mg fill2,105–4,310 mg compound4–8 capsules at 545 mg fill3–6 capsules at 730 mg fill2–4 capsules at 1100 mg fill
450 mg elemental Mg2,785–3,982 mg compound6–8 capsules at 545 mg fill4–6 capsules at 730 mg fill3–4 capsules at 1100 mg fill2,229–4,564 mg compound5–9 capsules at 545 mg fill4–7 capsules at 730 mg fill3–5 capsules at 1100 mg fill
475 mg elemental Mg2,939–4,204 mg compound6–8 capsules at 545 mg fill5–6 capsules at 730 mg fill3–4 capsules at 1100 mg fill2,353–4,817 mg compound5–9 capsules at 545 mg fill4–7 capsules at 730 mg fill3–5 capsules at 1100 mg fill
500 mg elemental Mg3,094–4,425 mg compound6–9 capsules at 545 mg fill5–7 capsules at 730 mg fill3–5 capsules at 1100 mg fill2,476–5,071 mg compound5–10 capsules at 545 mg fill4–7 capsules at 730 mg fill3–5 capsules at 1100 mg fill
525 mg elemental Mg3,249–4,646 mg compound6–9 capsules at 545 mg fill5–7 capsules at 730 mg fill3–5 capsules at 1100 mg fill2,600–5,325 mg compound5–10 capsules at 545 mg fill4–8 capsules at 730 mg fill3–5 capsules at 1100 mg fill
550 mg elemental Mg3,403–4,867 mg compound7–9 capsules at 545 mg fill5–7 capsules at 730 mg fill4–5 capsules at 1100 mg fill2,724–5,578 mg compound5–11 capsules at 545 mg fill4–8 capsules at 730 mg fill3–6 capsules at 1100 mg fill
575 mg elemental Mg3,558–5,088 mg compound7–10 capsules at 545 mg fill5–7 capsules at 730 mg fill4–5 capsules at 1100 mg fill2,848–5,832 mg compound6–11 capsules at 545 mg fill4–8 capsules at 730 mg fill3–6 capsules at 1100 mg fill
600 mg elemental Mg3,713–5,310 mg compound7–10 capsules at 545 mg fill6–8 capsules at 730 mg fill4–5 capsules at 1100 mg fill2,972–6,085 mg compound6–12 capsules at 545 mg fill5–9 capsules at 730 mg fill3–6 capsules at 1100 mg fill
625 mg elemental Mg3,868–5,531 mg compound8–11 capsules at 545 mg fill6–8 capsules at 730 mg fill4–6 capsules at 1100 mg fill3,096–6,339 mg compound6–12 capsules at 545 mg fill5–9 capsules at 730 mg fill3–6 capsules at 1100 mg fill
650 mg elemental Mg4,022–5,752 mg compound8–11 capsules at 545 mg fill6–8 capsules at 730 mg fill4–6 capsules at 1100 mg fill3,219–6,592 mg compound6–13 capsules at 545 mg fill5–10 capsules at 730 mg fill3–6 capsules at 1100 mg fill
675 mg elemental Mg4,177–5,973 mg compound8–11 capsules at 545 mg fill6–9 capsules at 730 mg fill4–6 capsules at 1100 mg fill3,343–6,846 mg compound7–13 capsules at 545 mg fill5–10 capsules at 730 mg fill4–7 capsules at 1100 mg fill
700 mg elemental Mg4,332–6,195 mg compound8–12 capsules at 545 mg fill6–9 capsules at 730 mg fill4–6 capsules at 1100 mg fill3,467–7,099 mg compound7–14 capsules at 545 mg fill5–10 capsules at 730 mg fill4–7 capsules at 1100 mg fill
725 mg elemental Mg4,486–6,416 mg compound9–12 capsules at 545 mg fill7–9 capsules at 730 mg fill5–6 capsules at 1100 mg fill3,591–7,353 mg compound7–14 capsules at 545 mg fill5–11 capsules at 730 mg fill4–7 capsules at 1100 mg fill
750 mg elemental Mg4,641–6,637 mg compound9–13 capsules at 545 mg fill7–10 capsules at 730 mg fill5–7 capsules at 1100 mg fill3,715–7,606 mg compound7–14 capsules at 545 mg fill6–11 capsules at 730 mg fill4–7 capsules at 1100 mg fill
775 mg elemental Mg4,796–6,858 mg compound9–13 capsules at 545 mg fill7–10 capsules at 730 mg fill5–7 capsules at 1100 mg fill3,839–7,860 mg compound8–15 capsules at 545 mg fill6–11 capsules at 730 mg fill4–8 capsules at 1100 mg fill
800 mg elemental Mg4,950–7,080 mg compound10–13 capsules at 545 mg fill7–10 capsules at 730 mg fill5–7 capsules at 1100 mg fill3,962–8,114 mg compound8–15 capsules at 545 mg fill6–12 capsules at 730 mg fill4–8 capsules at 1100 mg fill
825 mg elemental Mg5,105–7,301 mg compound10–14 capsules at 545 mg fill7–11 capsules at 730 mg fill5–7 capsules at 1100 mg fill4,086–8,367 mg compound8–16 capsules at 545 mg fill6–12 capsules at 730 mg fill4–8 capsules at 1100 mg fill
850 mg elemental Mg5,260–7,522 mg compound10–14 capsules at 545 mg fill8–11 capsules at 730 mg fill5–7 capsules at 1100 mg fill4,210–8,621 mg compound8–16 capsules at 545 mg fill6–12 capsules at 730 mg fill4–8 capsules at 1100 mg fill
875 mg elemental Mg5,415–7,743 mg compound10–15 capsules at 545 mg fill8–11 capsules at 730 mg fill5–8 capsules at 1100 mg fill4,334–8,874 mg compound8–17 capsules at 545 mg fill6–13 capsules at 730 mg fill4–9 capsules at 1100 mg fill
900 mg elemental Mg5,569–7,965 mg compound11–15 capsules at 545 mg fill8–11 capsules at 730 mg fill6–8 capsules at 1100 mg fill4,458–9,128 mg compound9–17 capsules at 545 mg fill7–13 capsules at 730 mg fill5–9 capsules at 1100 mg fill
925 mg elemental Mg5,724–8,186 mg compound11–16 capsules at 545 mg fill8–12 capsules at 730 mg fill6–8 capsules at 1100 mg fill4,581–9,381 mg compound9–18 capsules at 545 mg fill7–13 capsules at 730 mg fill5–9 capsules at 1100 mg fill
950 mg elemental Mg5,879–8,407 mg compound11–16 capsules at 545 mg fill9–12 capsules at 730 mg fill6–8 capsules at 1100 mg fill4,705–9,635 mg compound9–18 capsules at 545 mg fill7–14 capsules at 730 mg fill5–9 capsules at 1100 mg fill
975 mg elemental Mg6,033–8,628 mg compound12–16 capsules at 545 mg fill9–12 capsules at 730 mg fill6–8 capsules at 1100 mg fill4,829–9,888 mg compound9–19 capsules at 545 mg fill7–14 capsules at 730 mg fill5–9 capsules at 1100 mg fill
1000 mg elemental Mg6,188–8,850 mg compound12–17 capsules at 545 mg fill9–13 capsules at 730 mg fill6–9 capsules at 1100 mg fill4,953–10,142 mg compound10–19 capsules at 545 mg fill7–14 capsules at 730 mg fill5–10 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 citrate form group has 83 audited capsule labels and the magnesium sulfate group has 0; their distributions below use the mass-budget counts stored for each form, at powder density 0.6–0.8 g/mL.

Capsule mass budgets within each form group · 2026-08-10
Salt groupAll labelsAudited capsulesFits 0/00Needs 000Exceeds 000
Magnesium citrate21283264413
Magnesium sulfate40000

At 2026-08-10, magnesium citrate has 26 of 83 audited capsule labels at or below 730 mg minimum compound mass per capsule, 44 above 730 mg but at or below 1100 mg, and 13 above 1100 mg. Its other 129 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 sulfate has 0 of 0 audited capsule labels at or below 730 mg minimum compound mass per capsule, 0 above 730 mg but at or below 1100 mg, and 0 above 1100 mg. Its other 4 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 10 publications with magnesium citrate and 2 with magnesium sulfate; the combined list contains 10 unique publications, with shared records printed once.

Study-set membership · reviewed 2026-09-11
SaltPublicationsPublication years
Magnesium citrate101990–2025
Magnesium sulfate22005–2019

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

10 published measurements relevant to this pair

The 2026-09-11 literature review links these 10 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. Comparing the Bioavailability of Two Seawater-Derived Magnesium Preparations.

    Journal of medicinal food · 2025 · PMID 40955524

    Design
    Double-blind, randomized, three-arm crossover study in 20 healthy young men and women: placebo (maltodextrin), seawater-derived magnesium citrate (Aquamin-Mg, minimum 10% elemental magnesium), and seawater-derived magnesium hydroxide (Aquamin-MgTg, minimum 33% elemental magnesium). Total magnesium doses were standardized to the RDA for elemental magnesium.
    What it measured
    Incremental 18-hour urinary magnesium excretion as the relative-bioavailability marker; serum magnesium concentration at 1 and 2 hours post-ingestion (colorimetric assay, run in triplicate).
    Limits
    Small sample (n=20); healthy young adults only, not a magnesium-deficient or older population; only two seawater-derived preparations plus placebo were tested, no head-to-head comparison against standard magnesium citrate/oxide/glycinate salts; short observation window (18 h urine, 2 h serum).

  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. 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.

  10. 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 citrate: trace the filed inputs

8 of 212 labels mentioning magnesium citrate are shown in brand order from the supplied NIH DSLD records, calculated 2026-09-13. 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 2026-09-13
Brand / labelSalt / physical stateFiled servingObserved item price / EC100
Adaptogen Research Magnesium CitrateNIH DSLD 247099 · label 2021-05-22Magnesium citrateCapsule1 Capsule(s)150 mg elemental magnesium per servingNo published price matched to barcode 8 28054 70508 1 as of 2026-09-13.
Allergy Research Group Magnesium CitrateNIH DSLD 233067 · label 2020-08-23Magnesium citrateCapsule1 Capsule(s)170 mg elemental magnesium per servingNo published price matched to barcode 7 13947 70240 0 as of 2026-09-13.
Allergy Research Group Magnesium CitrateNIH DSLD 233300 · label 2020-08-23Magnesium citrateCapsule1 Capsule(s)170 mg elemental magnesium per servingNo published price matched to barcode 7 13947 76660 0 as of 2026-09-13.
Allergy Research Group Magnesium Malate ForteNIH DSLD 233224 · label 2020-08-23Single salt unresolved as of 2026-09-13Tablet or Pill1–2 Tablet(s)124 mg elemental magnesium per servingNo published price matched to barcode 7 13947 70740 5 as of 2026-09-13.
Allergy Research Group Magnesium Malate ForteNIH DSLD 304253 · label 2023-12-14Single salt unresolved as of 2026-09-13Tablet or Pill1–2 Tablet(s)124 mg elemental magnesium per servingNo published price matched to barcode 7 13947 70740 5 as of 2026-09-13.
AN Amazing Nutrition Amazing Formulas Magnesium Citrate 200 mgNIH DSLD 251825 · label 2021-08-23Magnesium citrateTablet or Pill1 Tablet(s)200 mg elemental magnesium per servingNo published price matched to barcode 8 10180 02665 9 as of 2026-09-13.
AN Amazing Nutrition Amazing Formulas Magnesium Citrate 200 mgNIH DSLD 256078 · label 2021-10-22Magnesium citrateTablet or Pill1 Tablet(s)200 mg elemental magnesium per servingNo published price matched to barcode 8 10180 02496 9 as of 2026-09-13.
AN Amazing Nutrition Amazing Formulas Magnesium Citrate 250 mgNIH DSLD 251815 · label 2021-08-23Magnesium citratePowder1.7 Gram(s) (1/2 Level Teaspoon)250 mg elemental magnesium per servingNo published price matched to barcode 8 10180 02763 2 as of 2026-09-13.

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

Magnesium sulfate: trace the filed inputs

4 of 4 labels mentioning magnesium sulfate are shown in brand order from the supplied NIH DSLD records, calculated 2026-09-13. Salt mentions can overlap; only records assigned this single salt enter its capsule audit above.

Filed labels in brand and product order · 4 labels · calculated 2026-09-13
Brand / labelSalt / physical stateFiled servingObserved item price / EC100
CVS Pharmacy Natural Calcium, Magnesium & Zinc USPNIH DSLD 12010 · label 2012-08-24Magnesium oxideUnknown1 Caplet(s)133 mg elemental magnesium per servingNo published price matched to barcode 0 50428 06542 6 as of 2026-09-13.
Douglas Laboratories Dyna-Cal Extra-Strength Natural Calcium/Magnesium ComplexNIH DSLD 9831 · label 2012-06-01Single salt unresolved as of 2026-09-13Tablet or Pill4 Tablet(s)420 mg elemental magnesium per servingNo published price matched to barcode 3 10539 01579 7 as of 2026-09-13.
Douglas Laboratories Dyna-Cal Extra-Strength Natural Calcium/Magnesium ComplexNIH DSLD 9832 · label 2012-06-01Single salt unresolved as of 2026-09-13Tablet or Pill4 Tablet(s)420 mg elemental magnesium per servingNo published price matched to barcode 3 10539 01239 0 as of 2026-09-13.
The Vitamin Shoppe Ionic MagnesiumNIH DSLD 204103 · label 2019-06-24Single salt unresolved as of 2026-09-13Liquid4 mL (4 droppers)400 mg elemental magnesium per servingNo published price matched to barcode 7 66536 03688 2 as of 2026-09-13.

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 2026-09-13, the published price set contains 9 verified magnesium citrate matches and 0 verified magnesium sulfate 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 citrate: its own retail sample

As of 2026-09-13, magnesium citrate has 9 verified matches and 10 pending matches in the price set. Its verified EC100 median is $0.1331 per 100 mg elemental magnesium (n=9); pending matches are excluded from that median. Observation dates: 2026-08-10 to 2026-09-11.

Magnesium citrate · verified observations · reviewed 2026-09-13 · n= 9

Magnesium citrate · verified observations · reviewed 2026-09-13 · n=
GNCMagnesium 250 mg Strawberry Natural FlavorNIH DSLD · Label 243072250 mg30$9.98Per container · Price observed 2026-09-07, Amazon$0.13317.50 total elemental g/containerVerified
GNCMagnesium Powder LemonNIH DSLD · Label 243047325 mg84$22.99Per container · Price observed 2026-09-07, Amazon$0.084227.30 total elemental g/containerVerified
Nature MadeMagnesium CitrateNIH DSLD · Label 179948250 mg30$10.89Per container · Price observed 2026-09-07, Amazon$0.14527.50 total elemental g/containerVerified
Nature MadeMagnesium CitrateNIH DSLD · Label 179947250 mg60$10.89Per container · Price observed 2026-09-07, Amazon$0.072615.00 total elemental g/containerVerified
Nature's SunshineMagnesium ComplexNIH DSLD · Label 255360184 mg50$19.95Per container · Price observed 2026-09-07, Amazon$0.21689.20 total elemental g/containerVerified
Natures PlusKalmAssure Magnesium Powder 400 mg UnflavoredNIH DSLD · Label 187441400 mg60$13.95Per container · Price observed 2026-09-07, Amazon$0.058124.00 total elemental g/containerVerified
Pure EncapsulationsMagnesium (Citrate)NIH DSLD · Label 201495150 mg90$20.50Per container · Price observed 2026-09-07, Amazon$0.151913.50 total elemental g/containerVerified
Pure EncapsulationsMagnesium (Citrate/Malate)NIH DSLD · Label 184671120 mg90$20.50Per container · Price observed 2026-09-07, Amazon$0.189810.80 total elemental g/containerVerified
SolgarMagnesium CitrateNIH DSLD · Label 219453420 mg30$15.29Per container · Price observed 2026-09-07, Amazon$0.121312.60 total elemental g/containerVerified
Magnesium citrate · pending observations · reviewed 2026-09-13 · n= 10

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

Magnesium citrate · pending observations · reviewed 2026-09-13 · n=
KALMagnesium Citrate 160 mg PowderNIH DSLD · Label 55106160 mg139$21.99Per container · Price observed 2026-08-10, Amazon$0.098922.24 total elemental g/containerPending verification
KALMalic Acid 1500 mg with MagnesiumNIH DSLD · Label 253228500 mg30$21.95Per container · Price observed 2026-08-10, Amazon$0.146315.00 total elemental g/containerPending verification
Nature's LabMagnesium Soothe 350 mg Raspberry LemonNIH DSLD · Label 207246350 mg100$17.99Per container · Price observed 2026-08-10, Amazon$0.051435.00 total elemental g/containerPending verification
Best NaturalsMagnesium Citrate 200 mgNIH DSLD · Label 269854400 mg125$17.21Per container · Price observed 2026-09-11, Amazon$0.034450.00 total elemental g/containerPending verification
Douglas LaboratoriesMagnesium CitrateNIH DSLD · Label 232777150 mg90$19.00Per container · Price observed 2026-09-11, Amazon$0.140713.50 total elemental g/containerPending verification
LES LabsMagnesium CitrateNIH DSLD · Label 320259225 mg120$20.99Per container · Price observed 2026-09-11, Amazon$0.077727.00 total elemental g/containerPending verification
NutriCologyMagnesium CitrateNIH DSLD · Label 235550170 mg180$31.79Per container · Price observed 2026-09-11, Amazon$0.103930.60 total elemental g/containerPending verification
Pure EncapsulationsMagnesium (Citrate)NIH DSLD · Label 294013150 mg180$36.50Per container · Price observed 2026-09-11, Amazon$0.135227.00 total elemental g/containerPending verification
SolgarMagnesium CitrateNIH DSLD · Label 219466420 mg60$15.29Per container · Price observed 2026-09-11, Amazon$0.060725.20 total elemental g/containerPending verification
SolgarMagnesium CitrateNIH DSLD · Label 241135420 mg60$15.29Per container · Price observed 2026-09-11, Amazon$0.060725.20 total elemental g/containerPending verification

Open the magnesium citrate label group →

Magnesium sulfate: its own retail sample

As of 2026-09-13, magnesium sulfate has 0 verified matches and 0 pending matches in the price set. No verified median is available as of 2026-09-13. Observation dates: No published observations as of 2026-09-13.

0 verified retail matches are published for magnesium sulfate as of 2026-09-13.

There are 0 pending price matches for magnesium sulfate as of 2026-09-13.

Open the magnesium sulfate 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.