Citrulline Vs Citrulline Malate
When it comes to improving performance and muscle growth, increasing nitric oxide production during training is one of the most effective methods.
Nitric oxide is a potent signaling molecule that promotes vasodilation in the body (the widening or dilation of blood vessels). The widening of blood vessels allows more blood to flow to your muscles, carrying more oxygen and essential nutrients with it. As a result, you’ll have more endurance, stamina, and overall performance, as well as a massive muscle pump.
You’ll also benefit from faster muscle growth and recovery in the long run.
As a result, the supplement industry has spent years researching different ways to increase nitric oxide in the hopes of finding the ultimate one-supplement solution for pumps, performance, and growth. Most of these ingredients, such as l-arginine, have proven to be ineffective in terms of increasing nitric oxide, performance, or muscle growth.
However, one ingredient that has been shown to be extremely effective for increasing nitric oxide production and can be found in your favorite pre workout supplement has emerged from the failures, frauds, and marketing ploys.
What is Citrulline Malate, and how does it work?
If you’re a regular reader of our Articles section, you’ve probably seen us extol the virtues of citrulline malate and why it’s regarded as one of the best pre-workout ingredients available. But, in case you’re new to Advanced Molecular Labs and/or aren’t a regular reader, here’s a quick rundown:
L-Citrulline is a non-proteinogenic amino acid (meaning it isn’t involved in the body’s protein synthesis) that is important in the Urea Cycle, a physiological process that aids in the removal of ammonia.
Ammonia is a metabolic waste product produced during intense exercise that causes fatigue and can be toxic to the body if not cleared properly. One of the main reasons you experience less fatigue when supplementing with Citrulline malate prior to training is because citrulline eliminates ammonia.
L-Citrulline is produced in the body as a byproduct of the breakdown of another conditionally essential amino acid, L-glutamine, or as a byproduct of the synthesis of nitric oxide with L-arginine. However, L-Citrulline can also be obtained through diet, as it is found naturally in a variety of fruits, including watermelon.
When citrulline enters your body, it is converted to arginine by your kidneys, which your body uses as “fuel” to produce nitric oxide. The more plasma arginine you can raise, the more nitric oxide you can produce, which leads to increased vasodilation, blood flow, performance, and pumps, as well as improved removal of metabolic waste products produced by exercise.
Let’s look at malic acid, which is the other half of citrulline malate.
Malic acid is an organic compound found in a variety of fruits, but it is especially abundant in apples. Malic acid is commonly used as a preservative in packaged goods to prevent spoilage because it is a weak acid. However, it has been shown to increase stamina and reduce pain caused by intense training sessions.
Malic acid boosts aerobic and anaerobic energy production by participating in the Krebs cycle (citric acid cycle or TCA cycle). The Krebs cycle is in charge of converting the food we eat into usable energy, specifically ATP, which is the cellular “currency” of exercise.
L-Citrulline or Citrulline Malate?
In the pre-workout industry, there’s been a bit of a “battle” recently, with some proclaiming the superiority of L-Citrulline over Citrulline Malate. So, if there is a difference between the two, what is it?
It is only the amino acid L-Citrulline that is added to a pre-workout supplement. There is no malate component, as there would be if you took citrulline malate supplements. Some people believe that the pure amino acid is more effective than citrulline malate, but what does actual human research say?
That’s when things start to get interesting.
There haven’t been any human studies comparing the two ingredients in terms of exercise performance, but based on the research done so far in humans on the two ingredients separately, it appears that L-Citrulline is a better option for aerobic or endurance exercise (i.e. “cardio”) than anaerobic exercise (resistance training).
Surprisingly, supplementing with L-Citrulline may not be beneficial at all, as several studies have found that when subjects take L-citrulline before exercising, their performance does not improve significantly.
The first experiment involved men running on a treadmill until they were completely exhausted.  The subjects were given 3 grams of l-citrulline three hours before exercising or 9 grams throughout the day leading up to the run. Not only did men fail to show any improvement in performance in both cases. In some cases, the men’s treadmill running times showed a decrease in performance.
Another study looked into the benefits of citrulline by giving university athletes one of the following supplements one or two hours before exercise:
- Juice from a watermelon (containing approximately 1 grams of l-citrulline)
- 6 grams of L-citrulline mixed with about 53 grams of sucrose in a drink (table sugar)
- Saccharide (placebo)
Athletes were required to bench press and then run until they were exhausted. Watermelon juice or citrulline supplementation provided no significant benefit to the subjects in terms of total number of repetitions, time to exhaustion, VO2max, or anaerobic threshold, according to the researchers. 
Furthermore, blood flow was unaffected by either l-citrulline source, indicating that there was no improvement in nitric oxide production or vasodilation.
Finally, eight healthy, recreationally active men consumed 300 mL of watermelon juice concentrate (containing 3.4 grams of L-Citrulline) per day for two weeks in a study. The goal of the study was to see if consuming the concentrate improved nitric oxide bioavailability and exercise performance in moderate and severe exercise.
There was no significant improvement in time to exhaustion during severe-intensity exercise at the end of the two weeks, and it actually increased blood pressure in the men rather than decreasing it. These findings support the notion that L-citrulline is marginally effective at best for moderate, steady-state intensity exercise, but it’s a poor choice for high-intensity work like sprints or resistance training.
So, what’s the deal with citrulline malate?
Studies have shown significant improvements in both leg and chest resistance training when subjects consume 8 grams of citrulline malate before working out. Individuals who took 8 grams of citrulline malate (the same dose as AML Pre Workout) before exercising did more repetitions and had a lower rate of perceived exertion (RPE) than those who took a placebo.
In addition, when compared to athletes who did not take citrulline malate, subjects who took 8 grams of citrulline malate experienced a 40% reduction in muscle soreness at 24 and 48 hours after training.
In other words, you should take citrulline malate supplements if you want to improve your bench and squat numbers (and who among us doesn’t? ), as well as feel less sore after working out.
Also, make sure you’re using the 8 gram dose, not the 4 or 6 gram doses that some companies claim to be the effective dose. Pre-workout doses of 8 grams of citrulline malate have been shown to improve weight-lifting performance in resistance-trained individuals. L-Citrulline, on the other hand, is a different story.
What’s the deal with the discrepancy?
The exact cause of the discrepancy between the two has yet to be determined, but it may have something to do with malic acid’s effects on the Krebs Cycle. Remember how we talked about malic acid as an intermediary in the Krebs cycle earlier?
What is the significance of this?
The krebs (or TCA) cycle produces ATP, which is the form of energy used by your muscles during high-intensity exercise like sprinting, jumping, or lifting weights.
The TCA cycle may be able to regenerate ATP more quickly with a greater supply of malic acid, which improves exercise performance and reduces recovery time between sets and after intense training. This could explain why citrulline malate is more effective than l-citrulline in terms of strength training results.
Citrulline Malate is the supplement of choice for serious athletes.
If you’re trying to decide between citrulline malate and l-citrulline to improve your performance in the weight room or on the field of competition, the choice is clear: citrulline malate.
The only form of citrulline shown to be beneficial for anaerobic exercise is citrulline malate, which is the form you want if you’re doing high-intensity exercise.
That’s why every serving of AML Pre Workout contains the full 8 gram clinically-verified dose of citrulline malate. Other pre-workouts try to get away with lower doses of citrulline malate while making claims and citing research that clearly states that 8 grams is the minimum amount required for peak performance.
We believe in doing everything we can to assist you in reaching your full potential. And in the case of citrulline malate vs. l-citrulline, that means you should always go with citrulline malate! We’ve also included 800mcg of folic acid as an added bonus to help citrulline malate work even better. Folic acid is required as a cofactor by the enzyme dihydrofolate reductase, which produces BH4 (tetrahydrobiopterin). The cofactor BH4 is required for the synthesis of nitric oxide.
In a similar way that citrulline malate increases the primary “fuel” that supports nitric oxide production, supplementing with folic acid increases the underlying compounds that support nitric oxide synthase and increase in nitric oxide (arginine). We’ve created a 1-2 punch for strong, unyielding nitric oxide production that supports maximum pumps and performance by combining folic acid and citrulline malate!
You deserve the best, which means high-quality products that are worth your hard-earned money.