Citrulline is one of the most hyped supplements for performance improvement, and for good reason. There is a substantial amount of scientific evidence backing its effects on both athletic performance and general health.
Citrulline (technically l-citrulline) is an amino acid. Malic acid is an organic compound found in fruits. Citrulline malate is an organic salt made by combining the two.
But what specific exercise benefits does citrulline malate have? What specific health benefits does citrulline malate have? How does it work in the body? And which brand sells it for the best price?
In this article we'll answer all of these questions and more as we analyze medical studies on citrulline malate to highlight four surprising research findings on its health and exercise benefits. We'll also share an animated video explaining how it works in the body.
We'll recommend a citrulline malate brand based on price and formulation, and answer some frequently asked questions about the compound.
Exercise Benefit #1: Improved Endurance
Citrulline can help improve endurance during both aerobic (cardio) exercise and anaerobic (resistance training) exercise. Citrulline is converted by the body to l-arginine, another amino acid. L-arginine is a nitric oxide (NO) precursor, so taking l-citrulline will increase NO levels. NO widens blood vessels and improves oxygen uptake in muscles during exercise.
A clinical trial published in the Journal of Strength and Conditioning Research tested the effects of citrulline malate ingestion on weightlifters performing repetitions to failure. They found that the group taking citrulline malate performed significantly more reps in all three exercises than the control group taking placebo.
Japanese researchers tested citrulline in healthy, trained volunteers before and after cycling 4 kilometers in a 2016 clinical trial.
The group taking citrulline not only finished 1.5% faster (a significant difference for athletes), but had less fatigue after exercise. They were only taking 2.4 grams (g) of citrulline daily which is a relatively low amount. Since it’s already been established in previous research that citrulline has a dose-dependent response, the results may have been even more significant with a higher dose.
Exercise Benefit #2: Improved Strength
A meta-analysis of 12 different studies on citrulline’s effect on strength and power in an athletic context was published in the Sports Medicine Journal.
The study authors documented that citrulline supplementation increased strength during resistance training exercise.
A clinical trial examined whether citrulline malate could improve the grip strength of female tennis players. The results showed that maximal grip strength improved by about 3%, and average grip strength improved by about 4% while supplementing with citrulline malate.
Health Benefit #1: Blood Pressure Support
The same biological mechanism for improved aerobic capacity is what causes a blood-pressure-lowering effect of citrulline in some individuals with high blood pressure.
When citrulline is converted into l-arginine, and then into NO, blood vessels widen and relax which can decrease blood pressure in those with high blood pressure.
In 2018, a meta-study was conducted to analyze the effect of citrulline supplementation on various cardiometabolic factors. The researchers found several different anti-hypertensive effects of citrulline. They concluded that “supplementation with l-citrulline has shown promise as a blood pressure lowering intervention” after examining both animal and human studies.
The Journal of Cardiology published a clinical trial on citrulline malate supplementation in patients with arterial hypertension. Arterial pressure dropped 5% in those supplementing with citrulline malate, even though the daily dose used (3 g) was relatively low.
Health Benefit #2: Improved Blood Flow
A 2017 clinical trial examined whether citrulline supplementation could improve blood flow during exercise in older adults. Blood flow increased by 11% in those supplementing with citrulline.
A 2013 clinical trial analyzed how citrulline supplementation affected blood flow. The researchers found that citrulline improved brachial artery flow-mediated dilation (FMD) in patients with a heart condition.
Endothelial function was found to be improved with citrulline supplementation, which is an important finding given that endothelial dysfunction is associated with cardiovascular disease.
We Tried Citrulline Malate Ourselves
As one of the authors of this article (Calloway), I wanted to try citrulline malate myself to share my thoughts on its effects in an athletic context.
I've been using citrulline for several months now (in either l-citrulline or citrulline malate form) before working out, and I've noticed a substantial improvement in cardio endurance while using this supplement.
I regularly play sports like tennis and basketball for hours at a time with minimal breaks, and when I take citrulline beforehand I feel very little cumulative fatigue (meaning even after the workout I don't feel particularly tired).
Another great thing about this supplement is that it's incredibly cheap per serving, and it's convenient. You just mix it into water, and it's tasteless.
Beyond the functional benefits, I like feeling like this supplement is supporting optimal cardiovascular health through increased NO.
I plan to keep using citrulline or citrulline malate (I take them interchangeably) for years to come.
How Does Citrulline Malate Work?
A YouTube creator named Dorian Wilson published an animated video highlighting some of the health benefits of citrulline malate and explaining how it actually works in the body. The video has over 230,000 views:
Our Clean Citrulline Pick
Nutricost Citrulline Malate is our top citrulline malate supplement pick.
This supplement is entirely free of questionable additive ingredients. It's a powder that can be added to any liquid. Consumers may wish to drink it with a straw (link to stainless steel straw brand) to prevent risks to tooth enamel, because like many supplements, citrulline malate is relatively acidic.
Nutricost Citrulline Malate is the most cost-effective citrulline supplement we've come across. It currently costs $29.95 and contains 196 servings, equating to a price of $0.15 per serving.
Citrulline Malate FAQ
Should I take arginine and citrulline malate together?
A clinical trial published in the Bioscience, Biotechnology and Biochemistry journal found that a combination of l-arginine and l-citrulline supplement increased l-arginine levels more than l-citrulline supplementation alone. This suggests that arginine and citrulline taken in combination may increase nitric oxide levels more than citrulline alone.
However, this was one single study and we will await further corroboration before changing our supplement recommendations.
Does citrulline malate help bodybuilding?
Due to its positive effects on strength and exercise endurance, citrulline malate may help bodybuilders improve their training regimen. The supplement should be taken 30-60 minutes before exercise at a dose of 3 g or greater.
Does citrulline malate work for erectile dysfunction (ED)?
There is preliminary research suggesting that citrulline supplementation may be beneficial for patients with ED. A study published in the Urology journal found that citrulline improved erections in patients with mild ED. More robust research is needed for a conclusive answer.
One natural compound that's been studied more for ED than citrulline malate is Asian ginseng.
Should citrulline malate be taken with pycnogenol?
We don't believe that there is currently enough research backing for stacking pycnogenol with citrulline malate.
There is more research on pycnogenol than citrulline for ED benefit, but there also isn’t as much data on the safety of this compound, so we recommend sticking to citrulline supplementation alone.
