Label arithmetic · NIH DSLD snapshot 2026-08-10
How much magnesium is in magnesium aspartate? 7.5–15.6% by weight, so 100 mg of magnesium takes 639–1,335 mg of aspartate
7.5–15.6% of magnesium aspartate is magnesium: 100 mg takes 639–1,335 mg of salt, 0.9–1.8 size 00 capsules. No ranked US price (Nov 2).
Magnesium aspartate is 7.5–15.6% elemental magnesium, so 100 mg of magnesium needs 639–1,335 mg of compound, about 0.9–1.8 size 00 capsules at 0.8 g/mL powder density. 0 of 15 capsule labels naming aspartate alone exceed size 000. No ranked offer; 3 price observations are on review as of 2026-10-26.
computed from chemical formula
Chart data
| Displayed chart text |
|---|
| oxide |
| 60.3% |
| hydroxide |
| 41.7% |
| carbonate |
| 24.8–28.8% |
| chloride |
| 12.0–25.5% |
| sulfate |
| 9.9–20.2% |
| citrate |
| 11.3–16.2% |
| aspartate |
| 7.5–15.6% |
| malate |
| 12.6–15.5% |
| glycinate |
| 11.8–14.1% |
| glycerophosphate |
| 12.5% |
| lactate |
| 10.2–12.0% |
| taurate |
| 8.9% |
| L-threonate |
| 8.3% |
| orotate |
| 7.3% |
| gluconate |
| 5.9% |
Data release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-10-26 · chemistry 2026-10-17
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How much elemental magnesium is actually in 100, 200 or 400 mg of aspartate?
Magnesium aspartate is 7.5–15.6% elemental magnesium by mass (MgC₄H₅NO₄, molar mass 155.39). Magnesium aspartate has a molar mass of 155.39 against magnesium's 24.305, so 7.5–15.6% of its mass is magnesium. One caveat: 1:1 magnesium aspartate 15.64%; bis(hydrogen aspartate) 8.42%, its dihydrate 7.49%; stoichiometry and hydration unresolved, so the figures below are given as a range wherever that matters. Every 100 mg of elemental magnesium from it needs 639–1,335 mg of the compound, calculated 2026-10-17.
computedThe filed salt can have more than one hydration state, so its elemental fraction is shown as a range.
Chart data
| Displayed chart text |
|---|
| aspartate |
| 2,558 · 5,340 |
| oxide |
| 663 |
| Elemental magnesium | aspartate required | Size 00 capsules that much powder fills |
|---|---|---|
| 100 mg | 639–1,335 mg | 1–2 size 00 capsules (0.9–1.8 capsules' worth of powder) |
| 200 mg | 1,279–2,670 mg | 2–4 size 00 capsules (1.8–3.7 capsules' worth of powder) |
| 400 mg | 2,558–5,340 mg | 4–8 size 00 capsules (3.5–7.3 capsules' worth of powder) |
1:1 magnesium aspartate 15.64%; bis(hydrogen aspartate) 8.42%, its dihydrate 7.49%; stoichiometry and hydration unresolved
Source · Chemical formula and atomic masses · Calculated 2026-08-10; powder density 0.8 g/mL, the top of the usual 0.6–0.8 range · 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 8 of 137 capsule labels across the audited registry. 13 fit size 0 or 00 and 2 need size 000. This is computed with a stated assumption of powder density 0.8 g/mL, the top of the usual 0.6–0.8 range and the most favorable mass per capsule.
computed with assumption15 capsule labels naming aspartate alone can be checked against capsule sizes.
Chart data
| Displayed chart text |
|---|
| aspartate |
| fits 13 of 15 |
| needs 000 2 of 15 |
| exceeds 0 of 15 |
| all audited |
| fits 82 of 137 |
| needs 000 47 of 137 |
| exceeds 8 of 137 |
| Mass budget verdict | Labels |
|---|---|
| Fits size 0 or 00 | 13 of 15 |
| Needs size 000 | 2 of 15 |
| Exceeds size 000 | 0 of 15 |
A size 00 capsule holds about 730 mg of powder at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range; a size 000 about 1,100 mg.
Source · NIH DSLD labels; mass balance · Recognized salt only; 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Is a label called aspartate really aspartate, or mixed with another salt?
0 of 25 labels naming aspartate also name another form as of 2026-08-10. The table counts partner names on filed labels; a named blend does not establish the elemental contribution of each salt. Naming one salt is not the same as fitting it: 0 of 15 capsule labels naming aspartate alone exceed size 000. Open the full label list to inspect individual records.
measuredA defined molecular formula permits a calculated fraction.
| Other named form | Labels |
|---|---|
| No other named form | 25 labels reviewed |
Source · NIH DSLD magnesium rows · Labels naming this salt; 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
I need 200 mg of actual magnesium. What changes in compound weight and capsules between aspartate and other forms?
For 200 mg of elemental magnesium, aspartate needs 1,279–2,670 mg of compound, against oxide at 332 mg. Size 00 holds about 730 mg at powder density 0.8 g/mL, the top of the usual 0.6–0.8 range. Each row uses the stated elemental fraction; hydration ambiguity stays a range, and any price comparison remains within a single salt.
computed with assumption| Salt | Elemental fraction | Compound for 200 mg | Size 00 capsules |
|---|---|---|---|
| Magnesium aspartate | 7.5–15.6% | 1,279–2,670 mg | 2–4 size 00 |
| Magnesium glycinate | 11.8–14.1% | 1,418–1,691 mg | 2–3 size 00 |
| Magnesium citrate | 11.3–16.2% | 1,238–1,770 mg | 2–3 size 00 |
| Magnesium oxide | 60.3% | 332 mg | 1 size 00 |
| Magnesium malate | 12.6–15.5% | 1,287–1,584 mg | 2–3 size 00 |
Source · Chemical formulas and capsule capacity · Calculated 2026-08-10; powder density 0.8 g/mL, the top of the usual 0.6–0.8 range · release 2026-08-10-f441aa9f · CSV · method
What does aspartate cost per 100 mg of elemental magnesium, and which label is cheapest by declared elemental magnesium?
No ranked price per 100 mg of declared elemental magnesium is available for aspartate as of 2026-10-26. 3 observations are on review; their pack or dose has not passed the match checks. The 25 recognized labels remain visible in the registry even where no US retail price is matched.
computedNo offer is ranked; 3 price observations are on review.
| Rank | Label | EC100 | Match and observation |
|---|---|---|---|
| On review | BulkSupplements.com Magnesium D-Aspartate | No ranked EC100 | pack weight differs: the offer lists 250 g, the label 1000 g; 2026-09-11 |
| On review | Swanson Magnesium Aspartate | No ranked EC100 | the offer is a multi-pack (2 packs); 2026-09-11 |
| On review | NOW Magnesium & Potassium Aspartate | No ranked EC100 | the offer is a multi-pack (2 packs); 2026-10-26 |
Source · Amazon via licensed data provider · Unique ASIN and observation date; prices observed 2026-10-26 to 2026-11-02 · release 2026-08-10-f441aa9f · CSV · method
What else is in aspartate labels, including stearate, shells and fillers?
8 named excipients appear in the top displayed list among 25 labels naming aspartate as of 2026-08-10. A listed ingredient is a filed name, not a quantified mass; open the underlying label to check context and capsule material.
measured
Chart data
| Displayed chart text |
|---|
| silicon dioxide |
| 17 |
| magnesium stearate |
| 15 |
| gelatin |
| 10 |
| stearic acid |
| 9 |
| cellulose |
| 5 |
| hypromellose |
| dicalcium phosphate |
| 4 |
| microcrystalline cellulose |
| microcrystalline |
| Filed ingredient | Labels |
|---|---|
| silicon dioxide | 17 of 25 |
| magnesium stearate | 15 of 25 |
| gelatin | 10 of 25 |
| stearic acid | 9 of 25 |
| cellulose | 5 of 25 |
| hypromellose | 5 of 25 |
| dicalcium phosphate | 4 of 25 |
| microcrystalline cellulose | 4 of 25 |
Source · NIH DSLD full label ingredient fields · Labels naming this salt; 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What did studies measure about absorption and side effects for aspartate?
2 studies in our PubMed checked registry measured outcomes involving aspartate as of 2026-08-10. The table names each design and measured outcome, against no pooled comparison across different study methods. No study in our registry of 16 measured side effects for aspartate as of 2026-08-10.
measured2 studies in this registry measured outcomes involving aspartate.
| Year | Study design and measured outcome | PubMed |
|---|---|---|
| 2005 | 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. 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. | PMID 16548135 |
| 2001 | Four commercially available US preparations given to healthy volunteers; bioavailability measured as the increment in urinary magnesium excretion. 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. | PMID 11794633 |
Source · PubMed checked study registry · Registry checked 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Which labels file aspartate, and how much do they declare per serving?
25 labels name aspartate; 24 have a computable elemental amount per serving, with median 100 mg, against the full list linked below. The first eight are shown here. Values are filed elemental magnesium, not an assay of the contents, in the NIH DSLD snapshot 2026-08-10.
measured
Chart data
| Displayed chart text |
|---|
| P10 29 mg |
| P50 100 mg |
| P90 495 mg |
| Label | Declared elemental per serving | NIH DSLD |
|---|---|---|
| AOR Advanced Orthomolecular Research Premium Magnesium Potassium Aspartates | Not determined | 214686 |
| Bronson Potassium & Magnesium Aspartate | 21 mg | 9135 |
| BulkSupplements.com Magnesium D-Aspartate | 49 mg | 310740 |
| BulkSupplements.com Magnesium D-Aspartate | 49 mg | 310742 |
| BulkSupplements.com Magnesium D-Aspartate | 49 mg | 310743 |
| Country Life Target-Mins Magnesium Potassium Aspartate | 600 mg | 327621 |
| Country Life Target-Mins Magnesium Potassium Aspartate | 600 mg | 333314 |
| Country Life Target-Mins Magnesium Potassium Aspartate | 600 mg | 333315 |
Source · NIH DSLD on-market labels · Labels naming this salt; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Where do these numbers come from, and how do I cite or correct them?
The 25 recognized aspartate labels come from the NIH DSLD snapshot 2026-08-10. Chemistry was calculated from molecular formulas on 2026-10-17; observed retail prices are checked 2026-10-26. The linked CSV carries only values displayed on this page. Cite the release and report a claim if a filed label or calculation needs correction.
computed| Layer | Source and date |
|---|---|
| Labels | NIH DSLD snapshot 2026-08-10 |
| Chemistry | Formula calculation 2026-10-17 |
| Retail | Prices observed 2026-10-26 to 2026-11-02 |
Source · NIH DSLD; chemical formulas; Amazon via licensed data provider · Release 2026-08-10-f441aa9f · release 2026-08-10-f441aa9f · CSV · method