L-Citrulline DL-Malate
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Compound | L-Citrulline DL-malate (citrulline malate) |
|---|---|
| Chemical class | Malate salt or co-crystal of L-citrulline — a non-proteinogenic amino acid |
| CAS | 54940-97-5 (citrulline malate) · 372-75-8 (L-citrulline) |
| Ratio — the key variable | 2:1 delivers ~72.3% citrulline · 1:1 delivers ~56.6% |
| Component MW | L-citrulline 175.19 · DL-malic acid 134.09 |
| Key applications | Pre-workout and endurance formats, nitric oxide substrate via arginine |
| Claim strength | Moderate for exercise endpoints; High that the ratio must be declared |
| Buy from Herbuno | L-Citrulline DL-Malate Powder · L-Citrulline 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: Citrulline was isolated from watermelon, Citrullus vulgaris, by Koga and Odake in 1914 and named for the genus. Malic acid takes its name from malum, apple, from which Scheele isolated it in 1785. Citrulline malate is the combination of the two, traded as a salt or co-crystal, and was developed in France where it has a long pharmaceutical history in asthenia before its adoption in sports nutrition.
Why the combination exists: The stated rationale is dual. Citrulline is the more effective precursor of plasma arginine than arginine itself, because it bypasses the intestinal and hepatic arginase that degrades most of an oral arginine dose. Malate is a tricarboxylic acid cycle intermediate, and the argument is that it supports aerobic ATP regeneration. The combination also improves handling: malic acid's acidity moderates citrulline's and gives a tart profile that suits the flavour systems used in pre-workout products.
Research trajectory: The frequently cited exercise trial that established citrulline malate's reputation used 8 grams of citrulline malate in a resistance exercise protocol and reported increased repetitions to failure and reduced soreness. Subsequent work has been mixed, with some trials replicating performance effects and others finding none, and the undeclared ratio in much of the literature makes dose comparison across studies unreliable. Pure L-citrulline has its own, somewhat cleaner, body of evidence.
Commercial source: L-citrulline is produced by fermentation, typically using Corynebacterium strains, and combined with DL-malic acid, which is manufactured synthetically from maleic or fumaric acid and is therefore racemic. The racemic designation is accurate and should not be read as a quality deficiency: synthetic malic acid is DL by nature, and it is the standard article in this combination.
Evidence for L-Citrulline DL-Malate Applications
The undeclared ratio is the dominant issue in this category and it changes citrulline content by a quarter. At the common 2:1 ratio, two parts citrulline to one part malic acid by mole, citrulline is approximately 72.3% of the mass; at 1:1 it is approximately 56.6%. Both are sold as "citrulline malate" and the ratio is frequently absent from the label and sometimes from the specification. A formulator dosing 8 grams of an undeclared material is delivering somewhere between 4.5 and 5.8 grams of citrulline. Requiring the ratio in writing is the single most important control in this category. Claim strength: High.
Citrulline is a genuinely better arginine precursor than arginine, and this is the strongest mechanistic claim available. 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 effects are inconsistent. Citrulline bypasses that pathway, is converted to arginine in the kidney, and raises plasma arginine more effectively per gram than arginine itself. This is well established and is the reason citrulline displaced arginine in pre-workout formulation. Claim strength: High.
The exercise performance evidence is moderate and less clean than the category implies. The most cited trial used 8 grams of citrulline malate before resistance exercise and reported more repetitions to failure and less soreness. Replication has been inconsistent. Meta-analytic work suggests a small benefit for high-intensity exercise performance, with substantial heterogeneity. A material contributor to that heterogeneity is dose ambiguity: with the ratio undeclared across much of the literature, trials nominally using the same dose may have differed by a quarter in citrulline delivered. Claim strength: Moderate.
The malate contribution is plausible but has not been isolated, and should not be overstated. Malate is a TCA cycle intermediate, so the argument that it supports aerobic ATP regeneration is biochemically coherent. What is missing is any trial comparing citrulline malate against an equivalent citrulline dose, which is the only design that could attribute an effect to the malate. Until that exists, the honest position is that malate's contribution is unquantified and the demonstrated effects may be citrulline's alone. Several practitioners take exactly that view and specify pure citrulline. Claim strength: Emerging.
Against that, the handling and flavour advantages of the malate are real and are often the actual reason for the choice. Malic acid's tartness integrates well with the citrus and berry flavour systems used in pre-workout products, moderates citrulline's own taste, and contributes to the acid profile that those formats require anyway. Where a formulation would otherwise add malic acid as an acidulant, supplying it bound to the citrulline is efficient. This is a formulation argument rather than a physiological one, and it is a legitimate basis for choosing the combination. Claim strength: High.
Tolerability is good and better than arginine's at equivalent arginine-raising capacity. Citrulline does not produce the dose-dependent gastrointestinal distress that limits oral arginine, which is one of its practical advantages; doses of 6 to 8 grams of citrulline malate are generally well tolerated. The malate contributes acid load, which matters in concentrated liquid formats and alongside other acidulants. As with arginine, the nitric oxide pathway warrants caution in anyone on nitrates or phosphodiesterase inhibitors. Claim strength: Moderate.
Sourcing L-citrulline DL-malate from Herbuno. We supply citrulline malate and pure L-citrulline.
Specify the ratio in writing — 2:1 or 1:1 — and dose on citrulline content rather than total mass. Without it there is a 25% swing in what you are actually delivering, and it is the most common failure in this category. If the formulation does not need malic acid as an acidulant, pure L-citrulline is the cleaner specification and the dose arithmetic is unambiguous. All lots ship with CoA and MSDS; request a quotation for pilot or bulk volumes.
Dosage & Formulator Specification
Dose on citrulline content and state the ratio. At 2:1, citrulline malate is approximately 72.3% citrulline, so 8 grams delivers about 5.8 grams of citrulline. At 1:1 it is approximately 56.6%, so the same 8 grams delivers about 4.5 grams. The commonly cited effective range is 6 to 8 grams of citrulline malate at the 2:1 ratio, equating to roughly 4.3 to 5.8 grams of citrulline, and pure L-citrulline trials have generally used 3 to 6 grams. Converting between the forms requires the ratio; without it, conversion is guesswork.
The specification should name the ratio, the citrulline assay and the malate content separately. A certificate reporting only "citrulline malate 99%" establishes nothing about the ratio and is not an adequate basis for dose calculation. Require the citrulline assay as a percentage of total mass, the malic acid content, and the stated mole ratio, with the three being mutually consistent. This is a straightforward request and a supplier who cannot meet it is worth reconsidering.
Handling is good and the combination is easier to formulate than either component alone would suggest. Citrulline malate is freely soluble in water, giving clear acidic solutions, and the tart profile integrates naturally with citrus and berry flavour systems. It is mildly to moderately hygroscopic and should be stored sealed, particularly in humid conditions, since caking in a pre-workout premix is a common complaint. The powder flows acceptably; anti-caking agents are often warranted in multi-component dry blends.
Acid load needs calculating across the whole formula rather than per ingredient. An 8 gram dose of 2:1 citrulline malate contributes roughly 2.2 grams of malic acid, which is a substantial acidulant load on its own. Stacked with beta-alanine, creatine HCl, added citric acid for flavour and an ascorbate, a reconstituted pre-workout can fall well below pH 3, which affects the stability of pH-sensitive co-ingredients and the palatability and enamel profile of the finished drink. Where citrulline malate is used, reduce or eliminate the separate acidulant rather than adding it on top.
For analytical control, specify L-citrulline identity and assay by HPLC with optical rotation confirming configuration, malic acid content, and the mole ratio. Specify L-ornithine and urea as process-related impurities, since both can arise in citrulline manufacture. Standard coverage includes heavy metals, residual solvents, microbiological limits, loss on drying and sulphated ash. For the citrulline component, which is fermentation-derived, specify residual host-cell protein and endotoxin and require the organism and substrate named for vegan, non-GMO, kosher and halal documentation. DL-malic acid is synthetic and its racemic nature is normal rather than a defect.
On form selection, the decision is reasonably clear once the malate's role is separated from the citrulline's. Choose citrulline malate where the formulation wants the acidulant anyway and the tart profile suits the flavour system — which describes most pre-workout powders. Choose pure L-citrulline where the dose arithmetic needs to be unambiguous, where a capsule format makes the acidity and bulk unhelpful, where the formula already carries sufficient acid, or where the technical documentation needs to cite citrulline's own trial literature without a ratio caveat attached. No trial has yet compared the two at matched citrulline doses, so there is no performance basis for preferring the combination, and the honest technical position is that the malate is chosen for formulation reasons.
Frequently Asked Questions — L-Citrulline DL-Malate
What ratio should I specify, and why does it matter?
2:1 or 1:1, and it matters by 25%. At 2:1 citrulline malate is about 72.3% citrulline; at 1:1 about 56.6%. Both are sold as "citrulline malate" and the ratio is often absent from the label and sometimes the specification. Dosing 8 grams of undeclared material delivers anywhere from 4.5 to 5.8 grams of citrulline.
Is citrulline better than arginine?
For raising plasma arginine, yes, clearly. Oral arginine is extensively degraded by intestinal and hepatic arginase before reaching circulation, which is why its vasodilatory effects are inconsistent. Citrulline bypasses that pathway and is converted to arginine in the kidney, raising plasma arginine more effectively per gram. That is why it displaced arginine in pre-workouts.
Does the malate do anything?
Unknown, honestly. Malate is a TCA cycle intermediate so the aerobic ATP argument is coherent, but no trial has compared citrulline malate against an equivalent citrulline dose, which is the only design that could attribute an effect to it. The demonstrated effects may be citrulline's alone. The malate's confirmed contribution is to taste and acid profile.
When should I use pure L-citrulline instead?
Where the dose arithmetic needs to be unambiguous, in capsules where the acidity and bulk are unhelpful, where the formula already carries enough acid, or where your technical documentation needs citrulline's own trial literature without a ratio caveat. For most pre-workout powders the malate's tartness is wanted anyway, so the combination is efficient.
What should the certificate show?
Three things, mutually consistent: L-citrulline assay as a percentage of total mass, malic acid content, and the stated mole ratio. "Citrulline malate 99%" alone establishes nothing about the ratio and is not a basis for dose calculation. Also specify L-ornithine and urea as process-related impurities.
Is DL-malic acid lower quality than L-malic acid?
No. Synthetic malic acid, made from maleic or fumaric acid, is racemic by nature, and it is the standard article in this combination. The DL designation is accurate rather than a deficiency. It is worth stating to customers who read it as a shortcut for an inferior grade.