What Is Citrulline Malate? | Benefits, Dosages & Side Effects

What is Citrulline Malate?

Citrulline Malate (CM) is an amino acid compound which has gained attention due to its reported ability to delay the onset of fatigue during intense exercise. That's why you’ll often find CM in pre-workout supplements. Let’s take a closer look at its components… 

Citrulline

Citrulline, sometimes referred to as l-citrulline, is a non-essential amino acid, meaning that it can be synthesised (produced) within the body. Once formed, citrulline is involved in various metabolic pathways — most notably, the urea cycle — and is a precursor for the amino acid Arginine. 

Arginine has a role in the production of Nitric Oxide which works as a vasodilator to improve blood flow and oxygen delivery around the body.¹ During aerobic exercise, skeletal muscle requires oxygen for energy production, therefore producing more NO leads to greater supply of oxygen to working muscles, and higher aerobic capacity, meaning you can push yourself to higher exercise intensities.²

Now, you may be thinking “why don’t we just supplement with arginine or NO?”. Well, citrulline has a longer half-life than arginine and NO, meaning that it circulates for longer once in our system, and is actually more effective at increasing levels of arginine than arginine supplements themselves.³ Think of citrulline supplementation as a stepping stone to boosting your body’s NO production. 

Malate

Malate is an essential intermediate of the Tricarboxylic Acid (TCA) Cycle, which generates two-thirds of the body’s energy by utilizing fats and carbohydrates consumed through the diet. In the TCA cycle, malate is dehydrogenised (stripped of its hydrogen atoms), which, in the process, generates NADH2. This co-enzyme can then go on to produce adenosine triphosphate (ATP), which is the energy needed for muscle contraction.⁵

Fundamentally, making sure your body has a sufficient amount of malate will keep the TCA cycle working smoothly and ensure your muscles have enough useable energy to keep you moving. 

Citrulline Malate Benefits

It’s all well and good understanding the nitty gritty about what goes on in our cells, but the question is, does citrulline malate really work and will it work for me? Luckily, research has the answers. 

Citrulline malate can delay muscle fatigue

During one cross-over study, resistance-trained men completed 5 sets of leg press, hack squat, and leg extension at 60% of one-rep max (the maximum weight you can lift for one repetition) until failure. Following the consumption of citrulline malate, the number of reps performed was significantly higher across all exercises compared to the placebo group.⁶ Being able to perform more reps equates to more Time Under Tension, which translates to superior muscle building. 

Similar effects have been observed in women, with citrulline malate supplementation increasing the number of reps completed of various upper- and lower- body resistance exercises, compared to the placebo. Not only this, but the women in this study reported lower ratings of perceived exertion after consuming citrulline malate.⁷ Imagine exercising for longer AND it feeling easier! 

If dumbbells aren’t your style, citrulline malate can also improve calisthenic exercise performance, such as chin-ups and pull-ups, as well as boosting explosive power during a cycling Wingate performance test.^8,9

Improves oxygen delivery to muscles

Not only does citrulline malate have benefits for power related exercise, it has also shown benefits in aerobic exercise.¹⁰

A few years ago, a research group put this to the test using a high-intensity cycling protocol, after participants had consumed either citrulline malate or placebo for the previous 7 days. In this case, citrulline malate increased the distance covered in a given time, improved capacity for oxidative metabolism, and lowered arterial blood pressure.¹¹So, if your goal is to improve endurance performance, a citrulline malate supplement might be worth a try. 

Citrulline Malate Dosage & Side Effects

Previous studies demonstrate that a daily dose of 6-8g of citrulline malate is sufficient to induce an ergogenic effect, though doses as low as 3g still offer performance benefits. Whether taken acutely as a single dose, or over several consecutive days, citrulline malate is considered safe to consume and doesn’t cause serious adverse effects.^9,11

FAQs

What is citrulline malate?

Citrulline malate is an amino acid which is involved in the production of Nitric Oxide, which improves blood flow. 

How much citrulline malate should I take before a workout?

Studies have shown 6-8g to show optimal results, however dosages of 3g offer performance benefits 

What are the benefits of citrulline malate?

Benefits of supplementing citrulline malate include delaying muscle fatigue and improving oxygen delivery to muscles. 

Does citrulline malate have any side effects?

Citrulline malate does not have any known adverse side effects. 

Take Home Message

All in all, citrulline malate looks like it has great potential as an ergogenic aid for both resistance and endurance performance. The citrulline component will help to boost nitric oxide production and shift unwanted ammonia, reducing muscular fatigue in the process. Meanwhile, malate will facilitate aerobic metabolism, making sure your muscles receive enough energy to handle your longer workouts.