Citrulline is gaining increasing popularity as a supplement that may increase blood flow, with some studies suggesting that it might help with power output and endurance during workouts. This non-essential amino acid is produced in the body, and it’s found in nature in legumes, organ meat, and especially watermelon — the name “citrulline” is actually derived from the Latin word for watermelon — and there are dozens of different supplements on the market including powders, pills, and citrulline malate, a form that might be more useful for improving energy production.
Best Citrulline Supplements
- Best Citrulline Overall: BulkSupplements L-Citrulline Powder
- Best Runner Up: BulkSupplements L-Citrulline DL-Malate 2:1
- Best Citrulline for Vegans: Doctor’s Best L-Citrulline
- Best Bulk Buy Citrulline: BulkSupplements L-Citrulline Powder
- Best Citrulline Pills: Nutricost L-Citrulline
- Best Citrulline Malate: BulkSupplements L-Citrulline DL-Malate 2:1
Best Citrulline Overall
This pick hits a lot of the essentials we like to see in a basic supplement like citrulline: It sports a low price, has a clean formulation, and you can buy it in bulk, which is why it scored our top spot overall.
BulkSupplements L-Citrulline Powder
Not only does this product come in bags up to 25 kilograms, but the manufacturer also states it’s free of added sugar, soy, dairy, yeast, gluten, and additives, with the only ingredient being L-Citrulline. Though this product is unflavored, that does mean you won’t find any artificial colors or sweeteners diluting your supplement. In addition to being a clean, straightforward supplement that’s tested in-house for purity, each serving only costs about $0.35, which is great for buying in 100-gram packages and 25-kilogram packages alike.
One of the most inexpensive citrulline supplements on the market, this product is tested for purity and free from major allergens, according to the manufacturer.
Who Should Buy BulkSupplements L-Citrulline Powder
- Folks who like buying their supplements in bulk to save money.
- Those who don’t want to have any colors or flavors added to their supplement.
Who Shouldn’t Buy BulkSupplements L-Citrulline Powder
- People who want a serving scoop to come with their purchase.
- Anyone looking for a flavored product.
- People who would prefer a pre-workout supplement with additional benefits that still includes citrulline.
This pick is clean, simple, cost-effective, and one of the top-rated products on the market — if you’re looking for an option that doesn’t hide its citrulline behind additives and artificial flavoring, BulkSupplements L-Citrulline is your answer.
Best Runner Up
For an option that’s easily absorbed and contains malic acid in addition to L-Citrulline, this pick harnesses the power of fruits to help increase your performance.
BulkSupplements L-Citrulline DL-Malate 2:1
BulkSupplements L-Citrulline DL-Malate 2:1 also contains DL-Malate. DL-Malate, or malic acid, is found in fruits and contributes to a sour taste like the one you find in some apples. This 2:1 ratio of citrulline to malic acid allows for quicker absorption and may help with stamina. This product is cost-effective and sold in bags of up to 25 kilograms — since each serving is only three grams, even if you double up, you’ll be set for many months.
Citrulline combined with malic acid, this product can boost absorption and increase stamina in one dose.
Who Should Buy BulkSupplements L-Citrulline DL-Malate 2:1
- Anyone who wants to absorb their citrulline supplement faster.
- Folks who like buying their supplements in bulk.
- People who are looking for a less expensive citrulline supplement.
Who Shouldn’t Buy BulkSupplements L-Citrulline DL-Malate 2:1
- Anyone who doesn’t like fussing with bag zippers — this one has been known to cause some issues.
- Those who want a scooper to come with their purchase.
- Customers who just want a citrulline supplement, without added malic acid.
Due to the malic acid, this product may absorb faster which could lead to increased stamina and better overall performance.
Best Citrulline for Vegans
Inexpensive and one of the few vegan-friendly citrulline supplements, Doctor’s Best has put together a solid product that is third-party tested and non-GMO.
Doctor’s Best L-Citrulline
The manufacturer ensures this product is vegan, non-GMO, soy-free, gluten-free, made in a cGMP facility (which means the FDA has given a thumbs up on the manufacturing facility), and perhaps most importantly, is third-party tested for label accuracy and purity. With so many options on the market that are third-party tested, you really shouldn’t consider one whose label hasn’t been fact-checked.
A well-priced citrulline that's vegan friendly and third-party tested for purity.
Who Should Buy Doctor’s Best L-Citrulline
- Folks who value products made in a current good manufacturing practices facility.
- Anyone who follows a vegan diet.
Who Shouldn’t Buy Doctor’s Best L-Citrulline
- Anyone anxious about secure packaging during delivery.
- Customers looking for a less expensive option — this pick does sell at a higher price point than some others on this list.
If you’re looking for a vegan-friendly product, this product’s label is fact-checked and completely free of animal products — though, you can expect to pay a touch more for its purity.
Best Bulk Buy Citrulline
When you want to buy as much citrulline as you can to avoid having to shop every month, this company sells a 25-kilogram bag — on average, most packs come with 500 grams.
BulkSupplements L-Citrulline Powder
As the name suggests, you can buy BulkSupplements in bags as large as 25 kilograms, but whatever the size of the package (they come as low as 100 grams), it’s a terrific value. The no-frills citrulline has no added ingredients and the final product is tested in-house for purity. BulkSupplements is extraordinarily inexpensive, allergen-free, and produced in a Good Manufacturing Practices-certified facility. BulkSupplements claims that the citrulline is “lab tested for verification and guaranteed purity,” though it’s unclear if this means third-party tested.
One of the most inexpensive citrulline supplements on the market, this product is tested for purity and free from major allergens, according to the manufacturer.
Who Should Buy BulkSupplements L-Citrulline Powder
- Anyone on a budget.
- Those who need a higher variety of serving size options.
Who Shouldn’t Buy BulkSupplements L-Citrulline Powder
- People who prioritize convenient packaging: this product doesn’t come with a scoop and the bag doesn’t seal.
- Those who want a citrulline supplement with added flavor.
If you are trying to keep supplement spending down and want a really solid product with simple ingredients, then look no further.
Best Citrulline Pills
For anyone on the go, these third-party tested, gluten-free capsules will keep you fueled for your workout even when you don’t have time to mix up a powder drink.
Nutricost L-Citrulline
Nutricost produces a lot of inexpensive supplements and their citrulline pills hit a nice sweet spot between quality and value. According to the manufacturer, the citrulline is non-GMO, it’s gluten-free, it’s made in an FDA-registered facility, and it’s third-party tested to ensure purity and label accuracy. On a per gram basis, this is a pretty inexpensive citrulline product, particularly given the fact that it comes in capsules. This form of citrulline is easy to consume on the go, which is a nice boon for avid travelers. If you’re a vegetarian, you’ll have to look elsewhere though as there is gelatin in these capsules. Additionally, the added fillers to streamline production could be a turn-off for some.
According to the manufacturer, this product is non-GMO, gluten free, made in an FDA-registered facility, and third-party tested, taking the cake when it comes to non-powder options.
Who Should Buy Nutricost L-Citrulline
- Anyone who prefers easy-to-consume supplements.
- Athletes who travel often with supplements.
- People on a tight budget.
Who Shouldn’t Buy Nutricost L-Citrulline
- The capsules are made from gelatin, so they’re not vegetarian-friendly.
- The capsules also contain magnesium stearate and stearic acid, which help keep the powder from sticking to the machinery in the facility in which it’s made — some consider these “fillers” undesirable.
If you are in the market for a capsulated citrulline supplement, then these are certainly a top-tier consideration, as long as you’re not vegetarian.
Best Citrulline Malate
For a product with a simple ingredient list and a solid dose of malic acid, this pick can be easily absorbed and has the potential to increase your stamina.
BulkSupplements L-Citrulline DL-Malate 2:1
Naturally found in fruits, malic acid contributes to the sour tastes in apples and is used to replicate that sour taste in some supplements. In addition to providing tartness, malic acid could also play a critical role in the citric acid cycle (or Krebs cycle) and allow for quicker absorption and increased stamina. Whether or not this leads to more reps in the gym is unclear, but citrulline malate could be a promising addition to your supplement stash if you prioritize absorption.
Citrulline combined with malic acid, this product can boost absorption and increase stamina in one dose.
Who Should Buy BulkSupplements L-Citrulline DL-Malate 2:1
- Those who like a tart taste in their citrulline powder.
- Anyone who wants the potential of increased stamina from malic acid.
- Customers who are looking for a cost-effective citrulline supplement.
Who Shouldn’t Buy BulkSupplements L-Citrulline DL-Malate 2:1
- Anyone who wants a scooper to come with their powder.
- Folks who prefer sweet flavors over tartness.
While the effects of malic acid still need some research, it may have the potential to help you pump heavier weights for longer at the gym, and if that’s something you’re interested in doing, BulkSupplements L-Citrulline DL-Malate 2:1 will not lead you astray.
How We Decided Our Picks
There are a handful of categories that we stuck to weed out the best of the best. Here is how we broke it down:
Dosage vs. Cost
Pretty straightforward ranking system here. If all products are created equal, we rank the less expensive options as better picks. That is, of course, an oversimplification of how we sifted through each pick, but it’s the general idea.
Some products lean into low cost being a huge incentive to pick them — see our best bulk buy option — but price only goes so far. There is also the matter of dosage. Dosage will vary from product to product and the ideal dosage is going to depend pretty much entirely on the consumers needs, so it can be tough to compare. However, if two products have similar per serving doses at a similar price, but one has more servings, then that one will obviously score higher.
Third Party Testing
This is really just a matter of wanting clean quality supplements. Once one competitive option gets third party tested and can verify the purity of their product, it puts the onus pretty heavily on that product’s competitors to do the same. If one product is third party tested and another is not, there is a significant boost in confidence that the product you think you’re buying is the product you’re getting.
Some products test for purity, but do so in house. That is a reasonable way to test, it is unlikely you’ll sell much product if your testing is flawed, but it doesn’t score as well as if a third party tested the product. There is just the inherent bias to test your own product favorably that we have to weight third party testing much more highly.
Form and Ingredients
This is subjective to the consumer, but the variances that come along with a powder versus a capsule are going to be obviously notable. A primary example of this is if a product is a capsule, is it made with something that will exclude vegetarians? On the flip side, if the product is a powder, how well does it mix? Is it flavored? Does it have any particular odor?
There are a lot of minute intricacies to sift through here and a big one is any added ingredients for the sake of easier manufacturing or to maintain form. An example is any additional preservatives or any added ingredients to create a capsule.
What Are the Benefits of Citrulline?
Citrulline is an amino acid that appears to increase plasma levels of arginine and ornithine, improving nitric oxide metabolism.(1)(2)(3) Nitric oxide seems to play a big role in relaxing blood vessels, which has implications for circulatory health and blood flow, and some studies have even linked it to improved erection hardness, making citrulline a somewhat popular supplement for erectile dysfunction.(4)(5)
For athletes, an increase in nitric oxide production might improve both anaerobic training (like sprinting) and aerobic (endurance-based) workouts, in addition to potentially reducing the amount of oxygen needed for exertion.(6)(7)(8)(9)(10) Citrulline itself has been seen in a few studies to improve power output and time to fatigue in cyclists and tennis players.(11)(12)
As for dosing, research in the International Journal of Cardiology and the European Journal of Applied Physiology found that a dose of 5 or so grams of citrulline may increase nitric oxide production and blood flow. (13)(14)
Citrulline vs Citrulline Malate
Citrulline is the pure amino acid, while citrulline malate is an organic compound that occurs naturally in many fruits. It’s citrulline combined with malic acid, which contributes to the sour taste of fruits — it’s abundant in apples and is often used as a flavoring in supplements. While citrulline does have links with improved performance, citrulline malate may also help to provide more energy for high intensity exercise because of its potential role in converting food into usable energy because of its role in in the Krebs cycle.
That’s the theory, anyway. Evidence is a little mixed; there is evidence, like a study published in 2010, that found citrulline malate to be useful at improving the number of repetitions in a training session and improve recovery, and another found it to postpone exercise fatigue in handball players.(15)(16) Other studies have found no effect on performance or muscle soreness.(17)(18)
At this time, we don’t have good research comparing the two supplements against one another and the additional benefits of adding malate aren’t concrete, but it’s a promising supplement nonetheless.
BarBend Tips
Be mindful of the dosage of citrulline. Many supplements will include one or two grams, but research suggests five to eight grams is ideal for the benefits.
It’s possible that loading citrulline over time may be an ideal way to accrue the potential benefits. Some users take a few grams every day for a week before expecting results. At the moment, there’s not quite enough evidence to suggest either acute or chronic dosing is superior.
If natural sources of citrulline are preferred, watermelon is widely considered the best source, though the exact amount present in a serving is unclear. Some estimate that there is about a quarter to half gram of citrulline per cup of watermelon flesh; it’s most concentrated in the white rind surrounding the flesh.
Side effects aren’t widely reported from citrulline supplementation. A very small minority experience upset stomachs or heartburn, so it may be prudent to start with a small dosage and gradually increase.
Wrapping Up
Citrulline is generally considered safe and today it’s one of the most popular ingredients in pre workouts. But always remember, especially if the intention is to take citrulline to improve circulatory health or erectile dysfunction, that it’s important to speak with a physician before starting a new supplement regimen.
References
1. Flam BR, et al. Endothelial nitric oxide production is tightly coupled to the citrulline-NO cycle. Nitric Oxide. 2007 Nov-Dec;17(3-4):115-21.
2. Sureda A, et al. Effects of L-citrulline oral supplementation on polymorphonuclear neutrophils oxidative burst and nitric oxide production after exercise. Free Radic Res. 2009 Sep;43(9):828-35.
3. Nakata M, et al. Endocrinology: nitric oxide-mediated insulin secretion in response to citrulline in islet beta-cells. Pancreas. 2003 Oct;27(3):209-13.
4. Moncada S, et al. The discovery of nitric oxide as the endogenous nitrovasodilator. Hypertension. 1988 Oct;12(4):365-72.
5. Cormio L, et al. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction. Urology. 2011 Jan;77(1):119-22.
6. Wylie LJ, et al. Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance. Eur J Appl Physiol. 2013 Jul;113(7):1673-84.
7. Lansley KE, et al. Dietary nitrate supplementation reduces the O2 cost of walking and running: a placebo-controlled study. J Appl Physiol (1985). 2011 Mar;110(3):591-600.
8. Kelly J, et al. Effects of short-term dietary nitrate supplementation on blood pressure, O2 uptake kinetics, and muscle and cognitive function in older adults. Am J Physiol Regul Integr Comp Physiol. 2013 Jan 15;304(2):R73-83.
9. Murphy M, et al. Whole beetroot consumption acutely improves running performance. J Acad Nutr Diet. 2012 Apr;112(4):548-52.
10. Lansley KE, et al. Dietary nitrate supplementation reduces the O2 cost of walking and running: a placebo-controlled study. J Appl Physiol (1985). 2011 Mar;110(3):591-600.
11. Suzuki, T. et al. (2016) Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study. J Int Soc Sports Nutr. 2016 Feb 19;13:6.
12. Glenn, JM. et al. (2016) Acute citrulline-malate supplementation improves maximal strength and anaerobic power in female, masters athletes tennis players. Eur J Sport Sci. 2016 Nov;16(8):1095-103.
13. Sureda A, et al. L-citrulline-malate influence over branched chain amino acid utilization during exercise. Eur J Appl Physiol. 2010 Sep;110(2):341-51.
14. Ochiai M, et al. Short-term effects of L-citrulline supplementation on arterial stiffness in middle-aged men. Int J Cardiol. 2012 Mar 8;155(2):257-61.
15. Pérez-Guisado J, et al. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010 May;24(5):1215-22.
16. Kiyici F, et al. The Effect of Citrulline/Malate on Blood Lactate Levels in Intensive Exercise. Biochem Genet. 2017 Dec;55(5-6):387-394.
17. Chappell AJ, et al. Citrulline malate supplementation does not improve German Volume Training performance or reduce muscle soreness in moderately trained males and females. J Int Soc Sports Nutr. 2018 Aug 10;15(1):42.
18. da Silva DK, et al. Citrulline Malate Does Not Improve Muscle Recovery after Resistance Exercise in Untrained Young Adult Men. Nutrients. 2017 Oct 18;9(10).