About the Product
Marvelous Nutrition's Citrulline Malate is a pure 2:1 Citrulline Malate powder supplement from the Old School line, with 3000mg of 2:1 Citrulline Malate per serving and 100 servings per package, produced by vegan fermentation (non-animal origin). 100% pure with no additives. 2:1 Citrulline Malate is the arginine precursor with the greatest clinical efficacy for increasing nitric oxide (NO) production, muscle pump, fatigue reduction, and improved post-workout recovery — and the amino acid with the highest number of high-quality clinical trials supporting its use in sports contexts. 3g/serving, 30 minutes before training. Vegan. Unflavoured.
Benefits
2:1 Citrulline Malate: the NO precursor with greater clinical efficacy and superior bioavailability to arginine:
2:1 Citrulline Malate is the form of citrulline with the most clinical evidence in sports nutrition. The 2:1 ratio denotes two moles of L-Citrulline for every mole of malic acid (malate), the combination with the highest documented bioavailability and efficacy compared to free L-Citrulline or 1:1 citrulline malate. As described in multiple products in this session (Experiment, INFECTED, Maze, Power M.F), L-Citrulline has a fundamental pharmacokinetic advantage over oral L-Arginine: while arginine undergoes extensive first-pass hepatic and intestinal metabolism by arginase (which converts it to ornithine + urea before reaching systemic circulation), citrulline is metabolically inert in the intestine and liver, being absorbed intact and transported to the kidneys where it is converted to arginine by arginino-succinate synthetase + arginino-succinate lyase of the renal urea cycle. The arginine thus produced in the kidneys enters directly into systemic circulation without passing through the liver, resulting in a sustained increase in plasma arginine levels for 4 to 6 hours — much longer than oral arginine (whose plasma peak is rapid but short-lived). The meta-analysis by Pérez-Guisado & Jakeman (2010) documented that 8g of Citrulline Malate improved the number of repetitions in the bench press by 52.9% vs. placebo and reduced post-workout muscle soreness by 40%.
The role of malate (malic acid) in the 2:1 formula: Krebs cycle and mitochondrial energy:
Malic acid (malate) in the 2:1 Citrulline Malate formula is not just an excipient or inert carrier — it is an active intermediate of the Krebs cycle (citric acid cycle) with documented effects on mitochondrial energy production. Malate is oxidized to oxaloacetate by mitochondrial malate dehydrogenase (NAD⁺-dependent), producing NADH (for the respiratory chain) and oxaloacetate (which condenses with acetyl-CoA to restart the Krebs cycle). Under conditions of high-intensity exercise where the Krebs cycle can be transiently limited by the availability of intermediates (especially oxaloacetate and fumarate), supplementation with exogenous malate can "recharge" the cycle and increase mitochondrial ATP production, reducing fatigue and prolonging the ability to maintain high intensity. This mechanism complements the vasodilatory effect of citrulline (via NO), creating a formula with dual action: more NO for O₂ and nutrient delivery (via vasodilation) and more Krebs cycle substrate for ATP production in muscle mitochondria.
Reduction of muscle fatigue: the role of citrulline in ammonia buffering:
In addition to NO, citrulline contributes to the reduction of muscle fatigue via a second mechanism linked to the urea cycle: citrulline increases the urea cycle's ability to eliminate ammonia (NH₃) produced by amino acid catabolism during exercise. The accumulation of ammonia in muscles and blood during high-intensity exercise contributes to central fatigue (ammonia crosses the blood-brain barrier and interferes with GABAergic and glutamatergic transmission) and muscle discomfort. Citrulline is an intermediate of the urea cycle — its conversion to arginine in the kidneys allows for the regeneration of arginine that arginase uses to produce urea (eliminating ammonia), thus increasing the body's total capacity for ammonia elimination. This effect partially explains the reduction in post-workout muscle soreness and improved recovery documented in clinical trials with citrulline malate.
Vegan fermentation: food-grade L-Citrulline of 100% plant origin:
The specification "vegan fermented L-Citrulline" confirms that the citrulline used in the product is produced by bacterial or fungal fermentation of plant substrates, without any animal origin. Natural citrulline is found mainly in the rind and pulp of watermelon (Citrullus lanatus — the name "citrulline" derives from the Latin word for watermelon), but direct extraction from watermelon is not economically viable on an industrial scale. Production by fermentation of pharmaceutical-grade L-Citrulline from plant substrates (using bacterial strains such as Corynebacterium glutamicum) guarantees a high-purity product (>99%), free of animal contaminants and suitable for vegan, vegetarian, and halal diets.
3g per serving: the clinically studied dose for pump and performance:
The dose of 3000mg (3g) of 2:1 Citrulline Malate per serving is within the dosage window documented in studies. Most positive clinical trials with citrulline malate used doses between 6 and 8g of 2:1 citrulline malate (equivalent to ~4 to 5.3g of free L-Citrulline), while doses of 3g of 2:1 citrulline malate (as in this product) are equivalent to ~2g of free L-Citrulline — a suitable dose for standalone use but which can be doubled (two 3g doses) to reach the maximum efficacy dose documented in the most robust studies, or supplemented with standalone Arginine for a combined effect of rapid onset (arginine) + prolonged sustenance (citrulline).
Uses
Recommended dose: Dissolve 3g in 250 to 400 ml of cold water, 30 minutes before training. For maximum pump effect in high-intensity workouts, you can use 6g (two servings) before training — a dose that replicates the doses of the most robust clinical studies. It can be mixed directly into your pre-workout shaker (INFECTED, Power M.F, Experiment) or added to standalone Arginine for the complete NO stack. For intra-workout use during long sessions, dissolve 3g in a second shaker for consumption mid-session, maintaining high plasma arginine levels throughout the entire workout.
