L-Arginine Alpha-Ketoglutarate
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 alpha-ketoglutarate (AAKG), 2:1 |
|---|---|
| Chemical class | Salt of L-arginine with 2-oxoglutaric acid, conventionally 2:1 |
| CAS | 16856-18-1 (2:1 AAKG) · 328-50-7 (alpha-ketoglutaric acid) |
| Component MW | L-arginine 174.20 · alpha-ketoglutaric acid 146.10 |
| Composition | Approx. 70.5% L-arginine at the 2:1 ratio (1:1 gives ~54.4%) |
| Counter-ion rationale | Alpha-ketoglutarate is a TCA intermediate and glutamate precursor |
| Claim strength | High for the chemistry; performance trials are null rather than merely thin |
| Buy from Herbuno | L-Arginine Alpha-Ketoglutarate 2:1 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 salt of L-arginine with alpha-ketoglutaric acid, also called 2-oxoglutaric acid, universally abbreviated AAKG. Alpha-ketoglutarate is one of the eight intermediates of the tricarboxylic acid cycle, sitting between citrate and succinyl-CoA, and it is also the keto acid corresponding to glutamate — the two interconvert directly by transamination and by glutamate dehydrogenase.
Why the salt exists: The commercial rationale was dual. Alpha-ketoglutarate is a genuine metabolic intermediate rather than an inert counter-ion, and its own nitrogen- scavenging and anaplerotic properties were presented as complementary to arginine's. AAKG is also freely soluble and less alkaline than free-base arginine, which suits powder formats. The salt became prominent in pre-workout products during the 2000s, when it was widely marketed as a superior nitric oxide precursor to arginine hydrochloride.
Research trajectory: AAKG occupies an unusual position in this catalogue: its performance literature is not merely thin but actively negative. Controlled trials in resistance-trained men examining AAKG supplementation have reported no improvement in strength, power, muscular endurance, or in haemodynamic and nitric oxide markers, and at least one found no change in plasma arginine kinetics sufficient to support the proposed mechanism. The alpha-ketoglutarate component has a separate and more interesting literature in clinical nutrition and, more recently, in ageing research as the calcium salt.
Commercial source: The arginine component is produced by fermentation; alpha-ketoglutaric acid is produced by fermentation or chemical synthesis. The two are combined and crystallised, conventionally at a 2:1 arginine-to-ketoglutarate mole ratio, though 1:1 material exists and the ratio is not always declared.
Evidence for L-Arginine Alpha-Ketoglutarate Applications
The performance trials are null, and that is a stronger statement than "insufficient evidence". Controlled studies in resistance-trained men have examined AAKG supplementation against strength, power and muscular endurance endpoints and reported no benefit; studies examining haemodynamic and nitric oxide markers have likewise found no meaningful change. This is not an absence of research but a body of research that failed to find an effect. A product positioned on AAKG as a superior nitric oxide precursor is making a claim that has been tested and not supported. Claim strength: High that the performance claim is unsupported.
The mechanistic reason for that failure is arginine's, not the salt's. Oral arginine is extensively degraded by intestinal and hepatic arginase before reaching the systemic circulation, so oral arginine raises plasma arginine inefficiently regardless of counter-ion, and plasma arginine is in any case not usually the limiting factor for endothelial nitric oxide synthesis in healthy people. Changing the salt does not address either problem. This is precisely why citrulline displaced arginine in pre-workout formulation: it bypasses the arginase first pass. Claim strength: High.
The ratio matters and is frequently undeclared. At the conventional 2:1 ratio — two moles of arginine to one of alpha-ketoglutaric acid — arginine is 348.40 parts in 494.50, or approximately 70.5%. At 1:1 it falls to approximately 54.4%. Both are sold as AAKG and the ratio is often absent from the label and sometimes from the certificate, giving a 23% swing in arginine delivered. Require the mole ratio and an arginine assay stated as a percentage of total mass. This is the same discipline citrulline malate and carnitine tartrate require. Claim strength: High.
Alpha-ketoglutarate itself is a more interesting molecule than the AAKG literature suggests, and its own evidence should not be conflated with AAKG's. As a tricarboxylic acid cycle intermediate it is anaplerotic; as the keto acid of glutamate it can accept amino groups, which is the basis of its use as a nitrogen scavenger in clinical nutrition; and calcium alpha-ketoglutarate has recently drawn attention in ageing research. None of that work used AAKG, and the alpha-ketoglutarate dose delivered by a typical AAKG serving is modest. Claim strength: Emerging, and attributable to alpha-ketoglutarate rather than AAKG.
Ornithine alpha-ketoglutarate is a distinct and better-evidenced article that is sometimes confused with AAKG. OKG, a 2:1 ornithine-to-ketoglutarate salt, has been studied in burns, trauma and surgical recovery with reported effects on nitrogen balance and wound healing, and is used in clinical nutrition in some markets. Its evidence does not transfer to AAKG, which pairs the same counter-ion with a different cation and has been tested separately with negative results. Claim strength: Moderate for OKG specifically.
Formulation properties are acceptable and are the one honest reason to specify AAKG. It is freely soluble, considerably less alkaline than free-base arginine, and delivers 70.5% arginine at the 2:1 ratio against the hydrochloride's 82.7% — so a lower density but no chloride load. Taste is sour and somewhat harsh from the keto acid. Where a customer's existing formula specifies AAKG, or where a chloride-free arginine source is wanted and the aspartate's lower density is unacceptable, AAKG is a reasonable article. On evidence grounds it is not. Claim strength: High.
Sourcing AAKG from Herbuno. We supply AAKG at the 2:1 ratio alongside L-arginine HCl, the aspartate and the free base.
We will supply AAKG where a customer's formula specifies it, and we will not support a nitric oxide or performance claim on it: the controlled trials in resistance-trained men came back null on strength, power, endurance and nitric oxide markers. If the objective is nitric oxide substrate, citrulline bypasses the arginase first pass that limits every arginine form and is the better specification. 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 ratio. At 2:1, AAKG is approximately 70.5% arginine, so 1 gram delivers about 705 milligrams of arginine and a 3 gram arginine target requires about 4.26 grams of AAKG. At 1:1 the arginine fraction falls to approximately 54.4%, so the same 3 grams of arginine would require 5.51 grams. Pre-workout products have commonly used 3 to 6 grams of AAKG, which is 2.1 to 4.2 grams of arginine at the 2:1 ratio — below the doses at which oral arginine shows any effect, which is a further reason the trials came back null.
Ratio specification is not optional. A certificate reading "AAKG 99%" establishes salt purity and nothing about arginine content, which depends entirely on the stoichiometry. Require the mole ratio stated, the arginine assay as a percentage of total mass, and the alpha-ketoglutaric acid content, with the three internally consistent. The 23% swing between 2:1 and 1:1 is well outside analytical tolerance and is the single most common specification failure in this category.
Handling is adequate with two constraints. AAKG is freely soluble in water, giving acidic solutions from the keto acid, and is moderately hygroscopic — more so than the hydrochloride, less than free-base arginine — so sealed packaging and humidity control during blending are advisable. Taste is sour and somewhat harsh, which integrates with citrus flavour systems but is difficult in neutral or dairy matrices. Alpha-ketoglutaric acid is also less stable in solution than the mineral or organic di-acid counter-ions, so liquid formats warrant accelerated stability data rather than assumption.
Form selection across the arginine series is best made on explicit axes. Free base: 100% arginine, strongly alkaline, markedly hygroscopic. Hydrochloride: 82.7% arginine, workable pH, 16.8% chloride, USP, EP and JP monograph coverage. Aspartate: 56.7% arginine, near-neutral, chloride-free, functional counter-ion. AAKG at 2:1: 70.5% arginine, acidic, chloride-free, metabolically active counter-ion, no supporting outcome evidence. The hydrochloride is the default for most applications on density and monograph grounds; AAKG's case is a customer specification or a chloride-free requirement where density matters more than it does for the aspartate.
For analytical control, specify L-arginine identity and assay with the basis stated, optical rotation confirming L-configuration, alpha-ketoglutaric acid content, and the mole ratio. Specify glutamic acid as a limit, since alpha-ketoglutarate and glutamate interconvert and glutamate can be present as a process-related impurity or a degradation product. Water content matters given the moderate hygroscopicity. Standard coverage includes heavy metals, residual solvents, microbiological limits, loss on drying and sulphated ash, with both production routes and the fermentation organism and substrate named.
Two distinctions worth carrying in customer documentation, because both cause real confusion. First, ornithine alpha-ketoglutarate is not AAKG: OKG pairs the same counter-ion with ornithine, has its own clinical nutrition literature in burns, trauma and surgical recovery, and its evidence does not transfer to AAKG, which was tested separately and found wanting. Second, alpha-ketoglutarate's own emerging literature — anaplerotic use in clinical nutrition, nitrogen scavenging, and the calcium salt's recent appearance in ageing research — belongs to alpha-ketoglutarate and not to AAKG, and the alpha-ketoglutarate dose delivered by a typical AAKG serving is modest in any case. A customer interested in that literature wants calcium alpha-ketoglutarate, which is a different article.
Frequently Asked Questions — L-Arginine Alpha-Ketoglutarate
Does AAKG work for nitric oxide or performance?
The trials say no. Controlled studies in resistance-trained men found no improvement in strength, power or muscular endurance, and none in haemodynamic or nitric oxide markers. That is a body of research that failed to find an effect, not an absence of research. A product positioned on AAKG as a superior NO precursor is claiming something that has been tested.
Why did it fail?
Arginine's problem, not the salt's. Oral arginine is extensively degraded by intestinal and hepatic arginase before reaching circulation, so plasma arginine rises inefficiently whatever the counter-ion — and plasma arginine is not usually limiting for endothelial NO synthesis in healthy people anyway. Citrulline bypasses the first pass, which is why it displaced arginine.
What ratio should I specify?
2:1 or 1:1, explicitly. At 2:1 AAKG is about 70.5% arginine; at 1:1 about 54.4% — a 23% swing, well outside analytical tolerance. Both are sold as AAKG and the ratio is often absent from the certificate. Require the mole ratio, the arginine assay as a percentage of total mass, and the ketoglutaric acid content, mutually consistent.
Is OKG the same thing?
No. Ornithine alpha-ketoglutarate pairs the same counter-ion with ornithine instead of arginine. It has its own clinical nutrition literature in burns, trauma and surgical recovery with reported nitrogen balance and wound healing effects. That evidence does not transfer to AAKG, which was tested separately with negative results.
Can I use the alpha-ketoglutarate longevity research?
Not on an AAKG product. That work uses calcium alpha-ketoglutarate, a different article, and the alpha-ketoglutarate dose delivered by a typical AAKG serving is modest in any case. A customer interested in that literature wants calcium alpha-ketoglutarate, and should be told so.
Is there any reason to specify AAKG?
Two, both formulation-led. A customer's existing formula calls for it, or a chloride-free arginine source is needed and the aspartate's 56.7% density is unacceptable — AAKG gives 70.5% with no chloride. Note it is acidic, moderately hygroscopic, and the keto acid is less stable in solution than organic di-acid counter-ions.