L-Arginine L-Aspartate
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Compound | L-Arginine L-aspartate |
|---|---|
| Chemical class | 1:1 salt of a basic and an acidic amino acid — both urea cycle participants |
| CAS | 7675-83-4 |
| Component MW | L-arginine 174.20 · L-aspartic acid 133.10 · salt 307.30 |
| Composition | Approx. 56.7% L-arginine · approx. 43.3% L-aspartate |
| Key property | Chloride-free, near-neutral in solution — unlike free base or hydrochloride |
| Claim strength | High for the formulation properties; Emerging for the fatigue literature |
| Buy from Herbuno | L-Arginine L-Aspartate Powder · L-Arginine HCl 99% 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 1:1 salt of L-arginine with L-aspartic acid. As with ornithine aspartate, neither ion is merely a counter-ion: arginine and aspartate are both urea cycle participants, arginine as the immediate precursor of urea and ornithine via arginase, aspartate as the donor of the cycle's second nitrogen via argininosuccinate synthetase.
Why the salt exists: Free-base arginine is strongly basic, giving a 10% solution above pH 10.5, which is unusable in flavoured liquids. The hydrochloride solves that but contributes 16.8% chloride and an acidic solution. Arginine aspartate solves it differently: the basic arginine and acidic aspartate largely neutralise one another, producing a freely soluble salt with a near-neutral solution pH and no chloride at all. That combination is not available from either parent compound.
Research trajectory: Arginine aspartate has a long European pharmaceutical history in asthenia and functional fatigue, marketed in France and elsewhere for decades. The supporting literature is largely old, small and of limited methodological quality by current standards, and no modern controlled trial has established a fatigue benefit. Separately, arginine aspartate appeared in some early growth hormone and exercise studies, with the same inconsistent results that characterise oral arginine generally.
Commercial source: The arginine component is produced by fermentation using Corynebacterium glutamicum or engineered Escherichia coli; the aspartate by enzymatic addition of ammonia to fumaric acid using aspartase, or by fermentation. The two are combined and crystallised as the 1:1 salt. Both ions must be specified as the L-form, since D-aspartate is a distinct compound.
Evidence for L-Arginine L-Aspartate Applications
The chloride-free near-neutral solution profile is the salt's real and distinctive advantage. Free-base arginine at 10% gives pH above 10.5, which rules out flavoured liquids, destabilises co-formulated actives and is harsh on mucosa. The hydrochloride corrects the pH but adds 168 milligrams of chloride per gram and an acidic solution. The aspartate salt gives a freely soluble, near-neutral solution with no chloride, because the basic and acidic ions balance. For a liquid, effervescent or low-sodium format carrying arginine, this is a genuinely different proposition from either parent. Claim strength: High.
The arginine fraction is 56.7%, which is the cost of that advantage and is lower than most formulators expect. At 307.30 g/mol against arginine's 174.20, 1 gram of the salt delivers 567 milligrams of arginine and 433 milligrams of aspartate. The hydrochloride delivers 827 milligrams of arginine per gram and the free base 1,000. So matching a 5 gram arginine dose requires 8.82 grams of arginine aspartate against 6.05 grams of the hydrochloride — a substantial difference in fill weight and scoop size. Claim strength: High.
The aspartate is a urea cycle participant rather than an inert counter-ion, which gives the combination a mechanistic rationale. Aspartate donates the second nitrogen of urea via argininosuccinate synthetase, condensing with citrulline, while arginine is cleaved by arginase to urea and ornithine. So both ions sit in the same cycle at different points. Whether supplying them together produces any effect beyond supplying arginine alone has not been tested, and the anaplerotic and nitrogen-handling contribution of a dietary aspartate dose is unquantified. Claim strength: Emerging.
The European fatigue literature is old and should not be relied upon. Arginine aspartate has been marketed in France and elsewhere for asthenia and functional fatigue for decades, and the supporting studies are largely from the 1980s and earlier, small, and of limited methodological quality by current standards. No modern controlled trial has established a fatigue benefit. The long market presence reflects regulatory grandfathering in those jurisdictions rather than accumulated evidence, and a formulator should know the difference. Claim strength: Emerging.
Arginine's own constraints are unchanged by the salt and limit what any arginine product can claim. Oral arginine is extensively degraded by intestinal and hepatic arginase before reaching the systemic circulation, which is why oral arginine raises plasma arginine inefficiently and why its vasodilatory and performance effects are inconsistent. Citrulline bypasses that pathway and raises plasma arginine more effectively per gram. No arginine salt addresses this, because it is a property of the molecule. Claim strength: High.
Tolerability is good and the absence of chloride and acidity helps at the margin. Oral arginine causes dose-dependent nausea, cramping and osmotic diarrhoea above roughly 9 to 10 grams of arginine in a single dose, and the aspartate salt does not change that threshold on an arginine-equivalent basis. It does avoid the gastric acidity of the hydrochloride, which is a modest benefit in sensitive individuals and in concentrated shots. The herpes simplex caution applies to any arginine product and warrants a note rather than silence. Claim strength: Moderate.
Sourcing L-arginine L-aspartate from Herbuno. We supply the aspartate alongside L-arginine HCl and the free base.
Take the aspartate where a chloride-free, near-neutral arginine source is needed — liquids, effervescents, low-chloride or low-acid formulations. Accept that it delivers 56.7% arginine against the hydrochloride's 82.7%, so fill weights rise by roughly 46% for the same arginine. We would not position it on the old European fatigue literature, which is small, dated and has not been replicated. All lots ship with CoA and MSDS; request a quotation for pilot or bulk volumes.
Dosage & Formulator Specification
Dose on arginine content and state the basis. At the 1:1 ratio the salt is approximately 56.7% arginine, so 1 gram delivers about 567 milligrams of arginine and a 3 gram arginine target requires about 5.29 grams of the salt. Set against the hydrochloride at 82.7% and the free base at 100%, the fill weight for equivalent arginine rises by roughly 46% over the hydrochloride. For a capsule format that is often decisive; for a liquid or effervescent, where the pH and chloride advantages apply, it is usually acceptable.
The selection logic across the three arginine forms is worth setting out plainly for customers, because the trade-offs run in different directions. Free base: highest arginine density, strongly alkaline, markedly hygroscopic, workable only in capsules under humidity control or where alkalinity is wanted. Hydrochloride: 82.7% arginine, workable pH for flavoured liquids, 16.8% chloride and acidic, monograph coverage in USP, EP and JP. Aspartate: 56.7% arginine, near-neutral, chloride-free, functional counter-ion, lowest density. No single form wins on every axis.
Handling is good. L-arginine L-aspartate is freely soluble in water, giving clear near-neutral solutions, and is only mildly hygroscopic — considerably better behaved than free-base arginine, which deliquesces. It flows acceptably as a crystalline powder, blends uniformly and is compatible with direct compression and automated capsule filling. Taste is mildly bitter with a faintly savoury edge from the aspartate rather than the saline note of a hydrochloride, which some flavour systems handle more easily.
The near-neutral pH is the property to design around. In an effervescent system it does not disturb the acid-carbonate balance the way a hydrochloride does, and in a flavoured ready-to-drink it allows the acidulant to be selected on flavour grounds rather than to correct an alkaline active. In a formula already carrying several hydrochloride salts, substituting arginine aspartate for arginine HCl removes a meaningful share of the total chloride and acid load. Those are real formulation levers and a better basis for specifying this salt than any physiological claim.
For analytical control, specify both components: L-arginine and L-aspartic acid assays as percentages of total mass, the mole ratio, and optical rotation or chiral methods confirming L-configuration on both ions, since D-aspartic acid is a distinct compound with its own pharmacology and price. Specify maleic acid as a limit where the aspartate derives from maleic-anhydride-sourced fumaric acid, since an amino acid assay will not catch it. Standard coverage includes heavy metals, residual solvents, microbiological limits, loss on drying and sulphated ash, with both production routes named for certification.
On claim construction, the honest framing is formulation-led. The defensible statements are the chloride-free near-neutral profile, the solubility, and the fact that aspartate is a urea cycle participant rather than an inert counter-ion — the last presented as mechanism, since no trial has compared the salt against an equivalent arginine dose with an inert counter-ion. Not defensible: the old European asthenia indication, which rests on small dated studies and regulatory grandfathering rather than replicated evidence. Not addressed by any arginine salt: the intestinal and hepatic arginase first-pass problem, which is why citrulline raises plasma arginine more effectively and why a customer whose objective is nitric oxide substrate should probably be redirected to citrulline rather than sold a different arginine salt.
Frequently Asked Questions — L-Arginine L-Aspartate
What does the aspartate salt give me that the hydrochloride does not?
A near-neutral solution and no chloride. Free arginine at 10% gives pH above 10.5, unusable in flavoured liquids; the hydrochloride corrects the pH but adds 168 mg chloride per gram and an acidic solution. The aspartate's basic and acidic ions balance, giving a freely soluble near-neutral salt with no chloride — not available from either parent.
How much arginine does it deliver?
56.7% — 307.30 g/mol salt against arginine's 174.20, so 1 gram gives 567 mg arginine and 433 mg aspartate. Against the hydrochloride's 82.7%, fill weight for equivalent arginine rises about 46%. Matching a 5 gram arginine dose needs 8.82 grams of aspartate against 6.05 grams of hydrochloride.
Is the European fatigue indication usable?
No. Arginine aspartate has been marketed in France and elsewhere for asthenia for decades, but the supporting studies are largely from the 1980s and earlier, small and of limited methodological quality. No modern controlled trial has established a fatigue benefit. The market presence reflects regulatory grandfathering, not accumulated evidence.
Which arginine form should I specify?
Depends on the axis. Free base for maximum density where alkalinity is tolerable and humidity is controlled. Hydrochloride for flavoured liquids with monograph coverage, accepting 16.8% chloride. Aspartate for near-neutral, chloride-free liquids and effervescents, accepting the lowest arginine density. No form wins on every axis.
Does the aspartate improve absorption?
No. Oral arginine's real limitation is extensive intestinal and hepatic arginase first-pass metabolism, and no salt addresses that — it is a property of the molecule. If raising plasma arginine is the objective, citrulline bypasses the pathway and does it more effectively per gram. We would redirect rather than sell a different arginine salt.
What should the certificate show?
Both components: L-arginine and L-aspartic acid assays as percentages of total mass, the mole ratio, and chiral confirmation on both ions — D-aspartic acid is a distinct compound with its own pharmacology and price. Plus maleic acid as a limit where the aspartate came via maleic-anhydride-sourced fumaric acid.