Like with many sports supplements, there are sometimes different forms that provide either additional benefits, or better efficacy.

Take creatine for example. There are several forms of creatine, such as ethyl ester, hydrochloride, or magnesium chelate, each offering better bioavailability, absorption rates, and overall increased effectiveness.

Same goes for L-citrulline! There are two popular forms, plain L-citrulline and citrulline malate.

This article discusses the difference between the two, and which one you should consider when looking to reap the benefits of this well-researched supplement!

What is L-Citrulline?

Starting with the basics: What is L-citrulline and what is it normally used for?

L-citrulline is one of the 3 amino acids in the urea cycle alongside L-arginine and L-ornithine. L-citrulline is thought to increase plasma levels of arginine and ornithine, which improves the production of nitric oxide.

There is a significant link between increased nitric oxide levels and improved sports performance.

Nitric oxide plays a primary role in regulating the delivery of oxygen to the muscles by relaxing and opening the blood vessels, also known as vasodilation.

As a result, blood flow is improved, which means lowered blood pressure and a decreased demand on your heart and muscles.

This increases the ability to support muscle contraction and transport by-products such as lactic acid, out of the working muscles.

This all translates to some significant enhancements in exercise performance, as increased nitric oxide essentially allows an individual to work out harder for longer.

Let’s take a closer look at the benefits!

What Are the Benefits of L-Citrulline?

Supplementing with L-citrulline has been shown to reduce blood pressure and increase blood flow. This translates into improved power output, reduced fatigue, and improved aerobic and anaerobic endurance exercise.

So, how does it all work?!

Well, upon ingestion of L-citrulline, it is converted into L-arginine in the kidneys. This means that L-citrulline is essentially a precursor to L-arginine.

L-arginine is what provides the blood flow benefits via increasing nitric oxide levels.

Though, you’re probably wondering why we don’t just recommend taking L-arginine.

Research has suggested that taking L-citrulline instead of L-arginine results in higher and more consistent levels of L-arginine compared to taking it as a standalone supplement. L-citrulline is better absorbed, making it a more effective supplement with minimal side effects.

Studies show a fairly substantial difference, so it’s definitely a good idea to take L-citrulline instead of L-arginine.

However, what about citrulline malate—is this a better form than L-citrulline alone?

L-Citrulline Vs Citrulline Malate: What’s The Difference and Which is Better?

The benefits of supplementing with L-citrulline are undeniable, as per the research. Though, what is the difference between the two forms, and which is better?

Citrulline malate is citrulline but bound to malate, an organic salt of malic acid. It is thought that citrulline malate may be the more effective form, however, this is a misconception.

Citrulline malate is a cheaper form of pure citrulline, which is why it’s more often used in research. This indicates that citrulline malate is the better form, whereas pure citrulline is likely the better option for the following reasons:

  • More active ingredient

It goes without saying that pure citrulline would provide 100% of the active ingredient. Malate would only provide citrulline in a ratio of 1:1 with malic acid. This means that citrulline malate supplements may not be as potent as pure citrulline.

  • Malate is cheaper

Citrulline malate costs a fair bit less to formulate, which is often why supplement companies push the use of it to keep costs down.

  • Gaps in the research

There has been some speculation on the benefits of malic acid as a standalone ingredient, though there are no concrete conclusions at the time of writing. Therefore, there is no compelling research to suggest the use of citrulline malate over pure citrulline.

Having said this, there is also currently no concrete research to suggest a significant difference in the effectiveness of one form over the other, so whichever one you choose is largely down to personal preference.

The Best L-Citrulline Supplement

Boosting the production of nitric oxide is a key to the secrets of boosting athletic performance.

There are few supplements that combine the most effective nitric oxide boosters, such as citrulline, beetroot, and glutathione.

Though, enter Pre Lab Pro—the next-gen pre-workout formula designed to boost the production of nitric oxide, helping to maximize performance supercharge your workout, and provide a head start on the recovery process.

Pre Lab Pro combines several ergogenic aids alongside pure L-citrulline for a sustained nitric oxide boost.

It is recommended to consume Pre Lab Pro 30-60 minutes pre-workout, giving you the boost required to perform to your peak potential.


L-citrulline is one of the most researched sports supplements in the industry. Due to the significant role it plays in nitric oxide production, it’s no wonder why it’s popular among so many athletes and gym-goers looking to boost performance, whether that be in relation to strength or endurance.

Nitric oxide is not a substance to overlooked or underestimated in the fitness industry. It plays a primary role in delivering oxygen and nutrients to working muscles via vasodilation (widening of the blood vessels).

With improved blood flow comes great benefits, such as lowered blood pressure and decreased demand on your heart and muscles.

As with many sports supplements, there are many different forms available, which makes it tricky to determine the best of the bunch.

While there still remains some speculation on which is the better form of citrulline, our recommendation is to always opt for the purer form of a supplement.

Better yet, combining L-citrulline with other nitric oxide boosters such as beetroot and glutathione would not go unnoticed during your next training session.

Pre Lab Pro is our top pick for an effective pre-workout which primarily centres around the benefits of boosting nitric oxide production.

An all-round ergogenic, supporting strength, stamina, speed, and recovery, suitable for all athletes on any level!