The Complete Guide To L-Citrulline

The Complete Guide To L-Citrulline

L-Citrulline is one of the most popular and potent pre-workout ingredients. 

It has shown to improve muscle pumps by increasing nitric oxide synthesis. By the same mechanism, it has an array of other benefits to improve your workout performance and support recovery.

While many people turn to the staple products such as creatine, caffeine, and beta-alanine to give them a boost, you won’t want to overlook the power L-Citrulline has. Once you try this supplement you won’t think twice about using it again.

Let’s go over what L-Citrulline is, its benefits, and how to take it for optimal results.

What Is L-Citrulline?

L-Citrulline is an amino acid that’s part of the urea cycle, which increases the level of ornithine and arginine in the blood. This means that using this supplement can improve the ammonia recycling process and nitric oxide metabolism in your body during training.

This helps to stave off the intense burning sensation you get in your muscles when weight training.

When ammonia builds up in the blood, most people quickly end their set to escape the feeling – potentially missing out on the most beneficial reps for their progress.

L-Citrulline also increases levels of arginine in the blood, which helps increase nitric oxide. This in turn leads to vasodilation (widening) of the blood vessels, which means increased muscle pumps.

Why not just supplement with arginine?

If L-Citrulline increases arginine, which increases pumps, wouldn’t it make more sense to supplement with arginine?

The reason is simple. L-arginine is not absorbed as easily in the gut. It can lead to stomach discomfort at the optimal doses for improved pumps and performance. L-Citrulline is simply a better way to get the same benefits.

The Benefits of L-Citrulline Supplementation

So, what benefits can you expect from using L-Citrulline?

Improved Muscle Pumps

As mentioned, L-Citrulline will lead to increases in nitric oxide.

Nitric oxide acts as a vasodilator in the body, meaning it’ll cause the blood vessels to expand, increasing blood flow.

This leads to improved muscle pumps. After taking L-Citrulline, you should notice that you feel full and more vascular during your workout. But what exactly are the benefits of improved pumps?

Improved Nutrient Delivery*

First, it means you’ll have increased blood flow to your muscle tissues, which equals better nutrient delivery.

When you have increased blood flow, your body will be able to more quickly get nutrients, from oxygen, to usable energy (ATP), to the other great ingredients in your pre-workout, where they need to go. This is what we mean by improved nutrient delivery.

Better Mind-Muscle Connection*

“The pump” is also famous for helping improve your mind-muscle connection. An improved mind-muscle connection means you’ll be able to “feel” the muscle more. It means you’ll have improved muscle activation and recruitment.


Subjectively, many report that an improved pump helps them focus on the exercise, which in turn will lead to a better set by virtue of being more present and centered on the exercise

There’s also an emotional and psychological component of "feeling the pump." It feels really good to feel the pump. This sensory feedback can be an incredible motivator. When you can feel your muscles working, it can create a positive feedback loop that enhances your commitment to each set. After all, it’s Arnold himself in Pumping Iron who compared the pump to the feeling of having sex. He said it, not us.

May Support Growth Hormone*

Growth hormone is one of the most powerful hormones in the body when it comes to building a better physique and feeling your best. It turns out that L-Citrulline may augment its release.

One study published in the European Journal of Applied Physiology noted that when subjects supplemented with oral L-Citrulline, they saw an increase in growth hormone production to the tune of 66.8%. (1) Now, increasing growth hormone levels is normal after exercise, but the researchers observed that the growth hormone increase was higher in the group that took citrulline.

Reduces Muscle Fatigue*

Improving blood flow may also reduce the buildup of ammonia. As we mentioned, this build up plays a factor in us “giving in” during a tough set. By reducing this build up, citrulline may reduce muscle fatigue.*

This is precisely what research published in the British Journal of Sports Medicine found. After six days of citrulline supplementation, the citrulline group reported a reduction in fatigue, a 34% increase in the rate of oxidative ATP production, and a 20% increase in the rate of phosphocreatine recovery after exercise. (2)

May Reduce Muscle Soreness*

Soreness is a part of training. However, excessive soreness can impair recovery, performance, and dissuade you from training hard the next time.

A 2020 systemic review and meta-analysis investigating 13 research studies on citrulline noted an overall reduction in muscle soreness both 24 and 48 hours after training with citrulline supplementation. (3) This is because the increased blood flow leads to better nutrient delivery. During and after your workout, citrulline can help your body deliver the nutrients it needs to support recovery, while clearing out waste products like lactic acid.

L-Citrulline Vs. Citrulline Malate: A Quick Comparison

Before you rush out to buy the first citrulline product or pre-workout with citrulline you come across, it’s important to note that not all products are created equally.

We only use and recommend L-Citrulline as opposed to Citrulline Malate. We cover the reasons why in this article on L-Citrulline vs Citrulline Malate.

To sum it up, if you purchase Citrulline Malate, you’ll be getting a 1:1 combination of L-Citrulline and Malic Acid by volume.

This means you are essentially getting half the dose of Citrulline. While this product may be beneficial, there is no data from human studies supporting the use of Citrulline Malate over pure L-Citrulline. Malate alone has not been demonstrated by research to provide the training benefits. Citrulline alone, in the form of L-Citrulline, has.  

Opting for pure L-Citrulline, you'll get more citrulline without any filler. get the optimal ratio of citrulline: 100% pure L-citrulline to support your workouts. This is the form you should be looking for when shopping for this supplement.

How Much L-Citrulline Should You Take Before Training?

To see optimal results from using L-Citrulline, consume 6-10g about 30-60 minutes before your workout session.

This is why in Kaged Pre-Workout we use 6.5g of L-Citrulline. This efficacious, research-backed dose will improve muscle pumps and provide the other benefits of pre-workout citrulline supplementation.

In Kaged Pre-Workout Elite, we take it further and give you 10g of L-Citrulline per scoop. This provides even more pumps.

We also have unflavored Fermented L-Citrulline powder, so you can add a boost of L-Citrulline to any stack.

Why We Use Plant-Based Fermented L-Citrulline

It’s not just about the form of citrulline. We believe quality starts at the initial source and the raw materials. That’s why in all Kaged pre-workouts, we used a plant-based, fermented form of L-Citrulline.

We believe the quality of an ingredient starts from the source, and we choose to start with raw plants for our aminos.

In contrast, some brands use l-citrulline made from untested ingredients like bird feathers, human hair, and shreds of animal carcasses. These low-quality sources are called “animal by-product.” Of course, this isn’t what you want to put in your body.

From the plants, our patented form of L-Citrulline, called Aminature® , undergoes a process of microbial fermentation, to further distill the amino acids.

After final purification, the result is a clean, plant-based L-citrulline.

Does L-Citrulline Post-Workout Have Benefits?

While L-Citrulline does offer various physiological benefits that can be applicable at different times, its impact is most pronounced when taken pre-workout.

Post-workout, the focus generally shifts towards recovery nutrients like protein.

While L-Citrulline may aid in recovery due to its potential to enhance blood flow and thus nutrient delivery, this is not the primary use case for this supplement. There's limited evidence to suggest that L-Citrulline can dramatically accelerate recovery when taken post-workout.


  1. Sureda, Antoni et al. “L-citrulline-malate influence over branched chain amino acid utilization during exercise.” European journal of applied physiology vol. 110,2 (2010): 341-51. doi:10.1007/s00421-010-1509-4
  1. Bendahan D, Mattei JP, Ghattas B, et alCitrulline/malate promotes aerobic energy production in human exercising muscleBritish Journal of Sports Medicine 2002;36:282-289.
  1. Rhim, Hye Chang et al. “Effect of citrulline on post-exercise rating of perceived exertion, muscle soreness, and blood lactate levels: A systematic review and meta-analysis.” Journal of sport and health science vol. 9,6 (2020): 553-561. doi:10.1016/j.jshs.2020.02.003

*These statements have not been evaluated by the Food and Drug Administration.  This product is not intended to diagnose, treat, cure or prevent any disease.

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