L Citrulline - Comprehensive Guide to Benefits and Dosage

L Citrulline - Comprehensive Guide to Benefits and Dosage

Known as one of the most popular pre-workout supplement ingredients, L-citrulline got its name from the Latin word citrullus - which means watermelon. Speaking of which, watermelon is the natural source of this supplement, although it is also present in foods like peanuts, soybeans and kidney beans.

But what actually is L-citrulline and why is it so special?

What Is L-Citrulline?

Basically, L-citrulline is a substance that is a non-essential amino acid. It is actively found and changed in our kidneys into another amino acid, called L-arginine and a chemical known as nitric oxide. Amazingly important for the heart and blood vessel health, these compounds play an active role in boosting the immune system.

The main effect of L-citrulline is to produce nitric oxide within the body, which is a substance that helps the arteries relax and work better. This significantly improves the blood flow throughout the body and may be helpful for either treating or preventing many diseases.

Most importantly, L-citrulline plays a key role in the urea cycle, a process where the body eliminates toxic byproducts that happen from digesting protein and generation cellular energy. These waste products are converted into a substance called urea, expelled from the body through the urine and sweat.

According to many studies and a lot of research, L-citrulline is a supplement that is able to lower the blood pressure in people who suffer from prehypertension - or act as the early warning sign for high blood pressure. This basically means that in a way, L-citrulline prevents high blood pressure and heart disease.

In other studies, it is shown that L-citrulline, when given to children through vein, is a great way to prevent blood pressure complications after a heart surgery. Since it relaxes the arteries, it is helpful in this manner and ensures a proper blood flow.

L-citrulline is also linked to prevention of erectile dysfunction, however, it does not work as well as Viagra or ED drugs used exclusively for this. Still, it is a safe option to unclog the blood vessels and stabilize the blood pressure.

The studies and results that most concern us, and this guide, are the effects of L-citrulline on muscle growth, athletic performance and how it improves the muscle protein levels while preventing all the side effects.

Before we focus on every single benefit of L-citrulline in detail, let's say a word or two about it as a supplement and the functions that it does.
Gym Workout

Why is L-Citrulline Supplementation Common?

There is a lot of buzz going around recently when it comes to citrulline supplementation, most generally in the malic acid salt form. Not only people believe that it is linked to physical performance enhancement and a lot of benefits - the results of supplementation with L-citrulline are seen even in the first months.

Speaking of which, there are four main reasons in which L-citrulline supplements the body:
  • It increases the blood flow
  • It improves the heart health
  • It boosts muscle growth and recovery
  • It increases the endurance
Additionally, L-citrulline is chosen over another popular supplement among athletes - L-arginine. This is mainly due to its ability to be absorbed in a better way and why it makes most of the workouts.

Since L-citrulline is absorbed better than L-arginine, it works better and turns it into the kidneys in a better way. Additionally, it elevates the plasma levels in the form of another amino acid, ornitine, which is also involved in the Urea cycle.

The 5 Greatest Benefits Of L-Citrulline

There are numerous benefits of L-citrulline as a supplement. And even though it is not as popular in the marketplace as creatine, beta-alanine or fish oil, L-citrulline definitely deserves more attention because of its amazing health and performance benefits.

Now, we listed the main benefits of this molecule in a short way above. Which is why we are focusing on them in more detail below.

1. L-Citrulline Improves The Physical Performance

According to research, supplementation with L-citrulline is a great way to improve both the resistance and endurance.

A solid proof for that is one study, where men doing resistance training were supplemented with 8 grams of L-citrulline before their chest workouts. The effects were miraculous - the number of reps they could do after the supplementation with L-citrulline went over 52%. In addition to that, the molecule significantly decreased the muscle soreness after the training.

There are many other studies on L-citrulline and its amazing effects on the physical performance. Generally, about 6 grams of L-citrulline per day are enough to increase the cellular energy production during exercise by 34% for average men and women, which is a significant number having in mind the average physical capacity.

2. L-Citrulline Stabilizes The Heart Health And Prevents Heart Disease

We have mentioned the effects of L-citrulline on arteries above. However, if you are not familiar with arteries...

They are basically blood vessels that flow the blood from the heart to all of the tiny capillary everywhere throughout the body, making sure that the body works with all of its functions. They are the link to every organ, streaming oxygenated blood directly from the heart.

As such, the arteries in our body contract and expand in order to control blood pressure. During this process, it is vital that they retain the ability to do this - because if they get stiff - there may be a potential heart disease, attack or stroke.

Nitric oxide is the main element that maintains the arterial health and function. Since L-citrulline works directly with it, it is proven to reduce blood pressure and keep the arteries flexible, relaxed and working the way they should.

That way, L-citrulline not only helps the arteries, but the entire heart and body as an organism which is a key factor in the overall health.

3. L-Citrulline Helps With Erectile Dysfunction

The ability to influence blood flow makes L-citrulline a direct advantage when it comes to erection. It is proven to give men harder erection and as such prevent erectile dysfunction. Knowing that the arteries and capillary is everywhere throughout the body, L-citrulline plays a key role in stimulating each of them to work to their fullest potential.

Most importantly, L-citrulline prevents erectile dysfunction which is a common disorder nowadays, and it does that with zero side effects.

4. L-Citrulline Reduces Free Radicals (And Therefore The Damage They Cause)

In case you don't know, free radicals are atoms or groups of atoms that can potentially cause damage to the cells in the body. While they are amazingly beneficial in many physiological processes necessary for optimal life, an excessive amount of free radicals leads to faster aging and age dependent diseases including:
  • Cardiovascular diseases
  • Cancers
  • Neurodegenerative disorders
  • Chronic conditions
L-citrulline steps into action by producing free radicals in the right dosage needed. While it is actively involved in the production of free radicals, it also helps the body deal with their excessive amount and reduce them accordingly.

5. L-Citrulline Is The Controller Our Body Needs

There are so many functions that L-citrulline does within the body in terms of control, making it the body's controller. Aside from the arteries and blood flow, the amino acid helps with:
  • Preserving the appropriate nitrogen level
  • Controlling the essential metabolic procedures
  • Preserving the acid-base balance in the body
  • Enhancing the immune system and overall wellness
  • Enhancing the energy levels and assisting in muscle recovery
  • Promotes the manufacturing of the hormone insulin, creatine and human growth hormone
  • Assists in getting rid of ammonia from the muscle cells and liver
  • Detoxifies and helps the body prepare for extensive and severe training
From all of the above mentioned benefits, it is clear that L-citrulline is a great amino acid that is not only used by athletes and bodybuilders - but also people who want to establish a balance in their body.

L-Citrulline As A Supplement: The Two Most Common Forms & The Right Dosage

Shaker CupIf you have decided to get L-citrulline as a supplement right now, you should know that the benefits are endless. However, you should also know that in order to see and feel those benefits, you need to take the right dosage of this supplement.

L-citrulline is basically found in two ways regarding its supplement form:
  • As L-citrulline
  • As citrulline malate
Basically, these two forms are the same with only one difference - the fact that the citrulline malate is L-citrulline combined with malic acid (hence the name), which is a natural substance found in fruits and involved in the creation of cellular energy.

Even though there is not so much information regarding supplementation with malic acid, there have been no strange cases. In fact, in a study with animals, it has shown improved endurance - not to mention the evidence that when combined with magnesium, this acid can treat fibromyalgia and many cardiovascular disorders.

That is why many supplements are labeled as citrulline malate, and why this name has won many hearts over the pure and standard L-citrulline. Still, when it comes to the right dosage, people have many questions.

What About The Right Dosage?

If you want to improve your exercise performance, you should take 3 to 5 grams of L-citrulline per day or 6 to 8 grams of citrulline malate per day accordingly.

Optimally, you should ingest citrulline about 15-30 minutes before training - but also during or after training if desired. If the dosage per day is too much for you to take in one go, you can increase it to 15-20g split into multiple doses throughout the day. However, make sure to consult with your doctor before doing that.

L-Citrulline And Results: Can They Be Seen In The First Month(s)?

If you don't know what to expect while supplementing yourself with L-citrulline, relax. You are not the only one. In the sea of people who are easily getting excited about this supplement, it is important to note that patience is key.

After all, supplements don't build great muscles and healthy bodies - as much as your dedication to proper training and a balanced diet.

That being said, the most common results from L-citrulline as a supplement that one should expect include improved circulation, endurance, capacity and higher energy - as well as decreased muscle soreness.

In order to help you experience those results - but not overdo your supplementation - it is also important to talk about the side effects of L-citrulline.

Longer Workouts - Less Fatigues And Sore Muscles - Insane Recovery

What happens when consuming L-citrulline is simple.

This amino acid accelerates the ammonia clearance as well as the free radicals clearance. By doing this, it postpones the inevitable decrease in muscle pH that happens during intense workouts. As the pH in the muscle drops, it becomes more acidic and the fatigue sets in.

In a study conducted in Spain in 2010, male strength athletes were given L-citrulline. The results were amazing - they were all able to achieve better results in bench press workouts - even up to 50% more repetitions when working to the point of muscular failure.

When it comes to soreness, citrulline is the answer to faster recovery. In another study in Spain, male professional cyclists were given citrulline malate in order to prove that. The results were once again amazing - their illnesses such as upper respiratory infections were gone, all thanks to the increased blood flow and delayed onset of the body's immunosuppressive mechanisms seen after intense exercise.

The citrulline's effects on protein and creatine synthesis were researched in a third study in Spain. The conclusion was simple - this supplement increased the blood arginine levels of the athletes, as well as a wide range of other benefits including elevated protein synthesis and creatine synthesis - as well as more efficiency in utilizing BCAA in the muscles during exercise.

This brings us to a proven conclusion - that L-citrulline and citrulline malate are great for performance, resistance, recovery and no fatigues or sore muscles.

The Side Effects Of L-Citrulline

Ever since its discovery in 1930, there have been no reports about side effects regarding L-citrulline and supplementing with it, even with high doses in both men and women. That being said, this supplement is generally safe to use.


The best way to ensure that there are no side effects is to never mix L-citrulline with certain medications including nitrates and drugs, especially ones for erectile dysfunction. As you probably know, it is better to be safe than sorry, so if you are breastfeeding or being pregnant, it's always better to check with your doctor before supplementing yourself with this amino acid.

On another note, an overdose of L-citrulline may potentially trigger some adverse effects, including:
  • interaction with some particular medicine that can reduce the effect or have a bad side effect
  • health conditions for people who have heart issues or cardio troubles
  • a hazardous and abrupt drop in blood pressure
  • potential risk if a woman is pregnant or breastfeeding
So to sum it up, supplementing with L-citrulline is only good when you are playing by the rules. This means that with the right dosage and under the right conditions, this is a supplement that creates no issues. However, the best way is to check with a medical person in case of any special conditions.

Frequently Asked Questions (FAQ) About L-Citrulline

These are some of the commonly asked questions about L-citrulline when used as a supplement.

Q: Can you eat watermelon rather than supplementing with citrulline?

Watermelons contain L-citrulline as part of them. However, most of its content is found in the rind of the actual fruit and is therefore not practical to obtain its doses through diet.

Q: What other foods are great sources of citrulline?

Aside from watermelons, citrulline is found in walnuts as a great natural source. In addition to it, protein-rich foods including fish, meat, milk, eggs etc. also contribute with adequate amounts of this amino acid.

Also, malate or malic acid present in fruits such as apples improve the effects of L-citrulline, which is why it is also available as citrulline malate supplement.

Q: Is citrulline good for enhancing the libido and treating impotence?

The blood flow that the L-citrulline increases creates another benefit - that helps improving erections among other things. However, this may not apply to each case and every scenario, particularly when it comes to conditions like impotence.

Q: Is it true that L-citrulline is taken on an empty stomach?

Although there is no stomach distress when L-citrulline is taken on an empty stomach, it is also fine to take it at meal times if you tolerate it well.

Q: How long does it take to see the results of citrulline?

As we said above and just like most of the supplements, L-citrulline is an amino acid which results vary for most of the individuals using it. However, there are some acute effects such as endotoxin removal that happen right after the first dose. Generally speaking, the most noticeable benefits such as increased strength and endurance are shown after a couple of weeks.

Q: Is there an optimal dosage of Citrulline for the best results?

Yes. According to most studies, the optimum dosage of L-citrulline for the best results is 8 grams daily. This was sufficient to causing an ergogenic effect during resistance training. However, scientists have also seen great performance benefits with dosages from 3 grams and above.

That is why for normal people, a single dose of 5 grams works best, while for athletes, the best way to consume L-citrulline as a supplement is around 7-8 grams per day.

Q: Why Is Citrulline Malate known as a great way to eliminate fatigue?

Because it is pump-boosting and increases performance and endurance, citrulline malate is a supplement that definitely delays the onset of fatigue during intense training. Many endurance athletes have confirmed this - along with the fact that this supplement has become a nearly obligatory ingredient in many pre-workout supplement plans.

Browse Through The Variety OF L-Citrulline And Citrulline Malate Supplements Today

L-citrulline is not a new supplement. However, there has been a lot of research and studies on its effects over the past decade - which is why it created so much hype and promised to be a great new discovery.

At Tiger Fitness, we pride ourselves on having a wide variety of citrulline supplements in our store. Carefully handpicked and proven to work and give amazing results, most of our performance-enhancing supplements based on citrulline also contain:
  • Caffeine - great for energy boost, increased muscle endurance and strength
  • Beta-alanine - an amino acid that occurs naturally. It reduces fatigue and improves exercise capacity
  • Betaine - a compound found in plants that is proven to improve the muscle endurance, strength and growth of the human growth hormone
  • Ornithine - another amino acid that reduces exercise fatigue and encourages lipid oxidation
  • Theanine - an amino acid that reduces the mental and physical stress while improving the alertness, focus and attention
Starting now, you have the chance to see why L-citrulline is becoming so popular nowadays, and why it is a great way to have better workouts, squeeze more weights, recover faster and most importantly - get rid of the fatigue and sore muscles.

All you need to do is visit our store and find the citrulline supplement that best tailors to your needs.

Have more questions - or maybe something else to share about this amino acid? We can't wait to hear your comments! Drop them below.
Previous article 10 Best Triceps Exercises for Mass