Magnesium Aspartate
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Compound | Magnesium aspartate — Mg(C4H6NO4)2 |
|---|---|
| Chemical class | Organic magnesium salt of L-aspartic acid, 1:2 metal to ligand |
| CAS | 2068-80-6 (anhydrous) · 7018-07-7 (dihydrate) |
| Molecular weight | 288.49 g/mol anhydrous · 324.52 g/mol dihydrate |
| Elemental magnesium | ~8.4% anhydrous · ~7.5% dihydrate — the lowest of the common salts |
| Comparison | Oxide ~60% · citrate ~11–16% · bisglycinate ~14% · aspartate ~8% |
| Claim strength | High for the elemental arithmetic; Emerging for aspartate-specific advantage |
| Buy from Herbuno | Magnesium Aspartate Powder · Liposomal Magnesium Bisglycinate Powder · Liposomal Magnesium Citrate Powder |
| Origin | Processed / Sourced from India |
| MOQ | R&D 100 g / 250 g (subject to stock) · Pilot batch 1–5 kg · Bulk 10 kg, 25 kg and above |
| Lead Time | Dispatch within 72 hrs from stock · fresh-batch production (typically 50 kg+): 10 working days |
| Documentation | CoA & MSDS standard with every lot |
Name origin: The magnesium salt of L-aspartic acid, in which one magnesium cation is balanced by two aspartate anions. Aspartic acid takes its name from Asparagus, via asparagine, the first amino acid ever isolated. The salt belongs to the family of organic-acid and amino-acid magnesium forms developed to improve on the inorganic salts.
Why the salt exists: Magnesium oxide is cheap and magnesium-dense but poorly absorbed and strongly laxative; the organic salts were developed to improve tolerance and absorption. Magnesium aspartate sits in that family alongside citrate, malate, glycinate, taurate and orotate. Its particular selling point historically was the aspartate itself as a urea cycle and malate-aspartate shuttle participant rather than an inert counter-ion.
Commercial history: Magnesium aspartate's best-known commercial appearance was in the ZMA formulations of the late 1990s, which combined zinc monomethionine aspartate with magnesium aspartate and vitamin B6 for sports nutrition. That positioning rested on correcting deficiency in athletes rather than on a pharmacological effect, and the trial record for the combination is mixed.
Commercial source: Magnesium aspartate is produced by reacting a magnesium source with L-aspartic acid, itself made by enzymatic addition of ammonia to fumaric acid. It is traded as the anhydrous salt and as the dihydrate, which carry separate CAS numbers and differ in elemental magnesium content.
Evidence for Magnesium Aspartate Applications
Elemental magnesium content is the specification, and aspartate's is the lowest of the common salts. At 288.49 g/mol anhydrous against magnesium's atomic weight of 24.305, the anhydrous salt is approximately 8.4% elemental magnesium; the dihydrate at 324.52 g/mol is approximately 7.5%. Against magnesium oxide at roughly 60%, citrate at 11 to 16% depending on hydration, and bisglycinate at around 14%, this is a substantial difference. A 100 milligram elemental magnesium dose requires about 1.19 grams of anhydrous aspartate against 167 milligrams of oxide. Claim strength: High.
That arithmetic largely determines the format. A 300 milligram elemental magnesium daily intake — a common supplement level — needs roughly 3.6 grams of magnesium aspartate, which is a sachet or multi-capsule regimen rather than a single capsule. Declaring "magnesium aspartate 500 mg" without the elemental figure tells a formulator almost nothing, since it corresponds to about 42 milligrams of magnesium. Dose and declare on elemental magnesium. Claim strength: High.
Organic magnesium salts are better absorbed than oxide, which is a low bar rather than a strong claim. Magnesium oxide's fractional absorption is poor and it is the most laxative of the common forms, so comparisons against it flatter every alternative. Comparative evidence establishing aspartate as superior to citrate, malate, glycinate or taurate is limited, and head-to-head trials among the organic salts are few. The honest position is that aspartate is one of several reasonable organic forms, not a demonstrated best. Claim strength: Emerging.
The aspartate is a metabolic participant rather than an inert counter-ion, which is a genuine mechanistic distinction without a demonstrated outcome. Aspartate donates the second nitrogen of urea via argininosuccinate synthetase and carries reducing equivalents in the malate-aspartate shuttle. Whether supplying it alongside magnesium produces any effect beyond supplying magnesium has not been tested. The aspartate also contributes a measurable amino acid load that should be counted in the formula rather than ignored. Claim strength: Emerging.
The laxative threshold applies to all magnesium salts and sets the practical dose ceiling. Unabsorbed magnesium retains water osmotically in the bowel, producing loose stools above an individual threshold; the threshold is higher for better-absorbed organic forms than for oxide or hydroxide but it exists for all of them. Because aspartate requires a large fill weight for a given elemental dose, the total material in the gut is high even where the magnesium is well absorbed, which is worth factoring into tolerance expectations. Claim strength: High.
Renal impairment is the significant contraindication and it applies to the element, not the salt. Magnesium is cleared renally, so impaired kidney function allows accumulation and hypermagnesaemia, which is a recognised clinical hazard. Any magnesium supplement warrants a caution for anyone with reduced renal function, and this is independent of which salt is used. Magnesium also interacts with several drug classes by chelation, notably tetracyclines, fluoroquinolones and bisphosphonates, which requires dose separation. Claim strength: High.
Sourcing magnesium aspartate from Herbuno. We supply magnesium aspartate, and bisglycinate, citrate, hydroxide and oxide in liposomal formats.
Specify elemental magnesium, the hydration state and the CAS number — 2068-80-6 anhydrous at ~8.4% magnesium, 7018-07-7 dihydrate at ~7.5%. This is the lowest elemental fraction among the common salts, so check the fill weight before committing to a capsule format: 300 mg of elemental magnesium needs roughly 3.6 g of aspartate. If magnesium density is the binding constraint, bisglycinate or citrate will serve better. All lots ship with CoA and MSDS; request a quotation for pilot or bulk volumes.
Dosage & Formulator Specification
Dose on elemental magnesium and state it on the label. Adult reference intakes sit around 300 to 420 milligrams daily depending on sex and jurisdiction, and supplemental products commonly provide 100 to 400 milligrams of elemental magnesium. Converting: divide the elemental target by 0.084 for the anhydrous salt or 0.075 for the dihydrate. A 100 milligram elemental dose is about 1.19 grams of anhydrous or 1.33 grams of dihydrate; a 400 milligram dose is 4.8 and 5.3 grams respectively.
Form selection should be made on explicit criteria rather than marketing. Oxide: ~60% magnesium, cheapest, poorly absorbed, most laxative — appropriate where magnesium density per unit is paramount and tolerance is secondary. Citrate: 11 to 16%, well absorbed, mildly laxative, soluble and suitable for liquids. Bisglycinate: ~14%, well tolerated, glycine is a useful co-ingredient. Aspartate: ~8%, well absorbed, functional counter-ion, lowest density. Hydroxide: ~41%, principally an antacid. For most supplement formats bisglycinate or citrate dominate on density and tolerance together.
Handling is straightforward. Magnesium aspartate is a white crystalline powder, moderately soluble in water, stable to heat and across a reasonable pH range, and mildly hygroscopic, so sealed packaging and humidity control during blending are advisable. It has a faintly bitter to saline taste, less aggressive than magnesium oxide's chalkiness but noticeable at the gram-scale inclusions this form requires. Bulk density is moderate; the fill weight rather than the flow is the constraint on capsule format.
Co-formulation should account for the amino acid load and for competing minerals. A 3.6 gram dose of magnesium aspartate contributes roughly 3.3 grams of aspartate, which is a real amino acid load and should be declared rather than treated as an excipient. Magnesium competes with calcium and zinc for absorption at high doses, so where all three appear in one formula, separating the doses or accepting reduced fractional absorption is the honest design. Vitamin B6 is conventionally paired with magnesium; the rationale is reasonable but the combination has not been tested as such.
For analytical control, specify elemental magnesium by atomic absorption or ICP with the basis stated, the hydration state confirmed by water determination, aspartate content, and the mole ratio. Specify optical rotation or a chiral method confirming L-aspartate, since D-aspartic acid is a distinct compound with its own pharmacology and price. Maleic acid is the relevant process-related impurity where the aspartate derives from maleic-anhydride-sourced fumaric acid. Standard coverage includes heavy metals, residual solvents, microbiological limits, loss on drying and sulphated ash.
Two label items belong at formulation rather than registration. First, the elemental magnesium figure must appear, because the salt weight alone is misleading by roughly twelvefold in this category and regulators in most markets require the elemental declaration. Second, a renal caution: magnesium is cleared renally and accumulates in impaired kidney function, so a hypermagnesaemia advisory is appropriate for any magnesium product. Add dose-separation guidance for tetracyclines, fluoroquinolones and bisphosphonates, which magnesium chelates — a practical interaction that affects real users and is cheap to state.
One point on the ZMA heritage, since customers still ask for it by name. The combination of zinc monomethionine aspartate, magnesium aspartate and vitamin B6 was positioned in the late 1990s on the basis that athletes in hard training are frequently zinc and magnesium insufficient and that correcting the insufficiency restores normal testosterone and IGF-1 rather than raising them above normal. That framing is defensible, and it is narrower than the marketing it generated: the benefit, where present, is correction of a deficit in a deficient person, not an anabolic effect in a replete one. Trial results have been mixed and the better-controlled work in adequately nourished athletes has generally been null. A customer specifying the combination should understand they are formulating a repletion product, and the defensible claim language follows from that.
Finally, a note on where this salt genuinely earns its place. Given the elemental arithmetic, magnesium aspartate is rarely the right choice when magnesium delivery alone is the objective — bisglycinate and citrate dominate on density and tolerance together. Its reasonable applications are reproducing an existing customer formula, a product where the aspartate is wanted for its own sake, and effervescent or liquid formats where the salt's solubility and mildly acidic character suit the system. Specifying it on a general absorption argument, when that argument rests on comparison against magnesium oxide, is the error worth heading off at quotation stage.
Frequently Asked Questions — Magnesium Aspartate
How much magnesium does it actually contain?
About 8.4% as the anhydrous salt and 7.5% as the dihydrate — the lowest of the common magnesium forms. A 100 mg elemental magnesium dose needs roughly 1.19 g of anhydrous aspartate. "Magnesium aspartate 500 mg" corresponds to only about 42 mg of magnesium.
Can I deliver a normal magnesium dose in capsules?
Not comfortably. A 300 mg elemental daily intake needs about 3.6 g of magnesium aspartate, which is a sachet or a multi-capsule regimen. If capsule count matters, bisglycinate at ~14% or citrate at 11 to 16% halves the fill weight; oxide at ~60% cuts it dramatically, at the cost of absorption and tolerance.
Is aspartate better absorbed than other forms?
Better than oxide, which is a low bar — oxide's fractional absorption is poor and it is the most laxative form, so comparisons against it flatter everything. Head-to-head evidence establishing aspartate as superior to citrate, malate, glycinate or taurate is limited. It is one reasonable organic form, not a demonstrated best.
Does the aspartate contribute anything?
Mechanistically it is a urea cycle and malate-aspartate shuttle participant rather than an inert counter-ion, which is a genuine distinction. Whether that produces any effect beyond supplying magnesium has not been tested. It does contribute a real amino acid load — about 3.3 g per 3.6 g dose — which should be declared.
What cautions does the label need?
A renal caution, since magnesium is cleared renally and accumulates in impaired kidney function — hypermagnesaemia is a recognised hazard. And dose separation from tetracyclines, fluoroquinolones and bisphosphonates, which magnesium chelates. Both apply to the element regardless of salt.
What should the certificate state?
Elemental magnesium by atomic absorption or ICP, the hydration state confirmed by water determination, aspartate content and the mole ratio, plus chiral confirmation of L-aspartate — D-aspartic acid is a distinct compound at a different price. Also maleic acid as a limit where the aspartate came via maleic-anhydride-sourced fumaric acid.