Best Citrulline Supplements for Pre-Workout, Vegans, and More

Citrulline is a popular pre-workout 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 abundantly in 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.

Whether you’re looking for a straightforward citrulline supplement, a pre-workout with citrulline, or even a nitric oxide supplement that contains citrulline, we’ve done some digging to find the best citrulline supplements on the market today. Stick with us to pick one out for yourself, and learn about all the potential benefits citrulline has to offer. 

Best Citrulline Supplements

• Best Pre-Workout for Citrulline: Transparent Labs BULK Black
• Best Citrulline for Nitric Oxide Production: Transparent Labs L-Citrulline
• Best Citrulline Pills: Nutricost L-Citrulline
• Best Citrulline for Vegans: Doctor’s Best L-Citrulline

Best Pre-Workout for Citrulline: Transparent Labs BULK Black

Who Should Buy Transparent Labs BULK Black

• Folks looking for citrulline within a pre-workout supplement will like this product.
• Athletes looking for a high dose of citrulline — this supp has 8,000mg. 
• People who want an extensive supplement will appreciate that this product contains 17 helpful ingredients. 

Who Shouldn’t Buy Transparent Labs BULK Black

• Those who want a simpler citrulline supplement without all the added ingredients of a pre-workout. 
• Customers who want a product that is free of caffeine will want to look elsewhere. 

This supplement is more than just a citrulline product — it contains a wide range of potently dosed pre-workout ingredients, including a high dose of citrulline. 

Transparent Labs BULK Black contains 17 high doses of pre-workout ingredients. It has 8,000mg of citrulline malate, 4,000mg of beta-alanine, 275mg of caffeine, and 2,500mg of betaine anhydrous. All of these numbers are above the market average when it comes to pre-workouts.

BULK Black also contains 1,000mg of tyrosine that can help with focus. Another bonus? Transparent Labs’ website provides ingredient descriptions for its whole label, so you know exactly what you’re sipping before your workout. It will also cost you around $1.83 per serving, which isn’t bad considering this is an entire pre-workout supplement.

If you already take a pre-workout, it may be convenient to have a pre-workout that contains citrulline, so you don’t need to add another supplement to your regimen — this pick checks that box.

Read our full Transparent Labs BULK Black Review.

Best Citrulline for Nitric Oxide Production: Transparent Labs L-Citrulline

Who Should Buy Transparent Labs L-Citrulline

• Anyone who wants a simple l-citrulline supplement that’s simple and solely focused on boosting nitric oxide.
• Folks who don’t want any added sugars.
• People who prefer to avoid caffeine intake with their supplements will enjoy this stimulant-free formula. 

Who Shouldn’t Buy Transparent Labs L-Citrulline

• Those who want a more robust formula can find more elaborate products.
• Customers who are looking for flavored products that are more refreshing to sip on their own.

If your main focus is nitric oxide production, you want l-citrulline to be a main ingredient in your supplement of choice. That’s because your body converts l-citrulline into nitric oxide. So, for a straightforward supp, Transparent Labs L-Citrulline is the one to add to your cart. This product only contains l-citrulline (2,000mg per serving) with no added sweeteners, flavorings, or preservatives. 

Other products, like our pre-workout pick above, may have higher levels of l-citrulline per serving. However, TL recommends adding an extra scoop for enhanced recovery (but if you have pre-existing conditions or are new to the supplement, it’s best to double check with your doctor). And considering this supp contains 120 servings per tub, you don’t have to be too stingy about adding an extra scoop or two. 

Although Transparent Labs’ product does have a super inexpensive serving size (only about $0.15 per serving), it doesn’t come in any flavor options, only unflavored. So, if you’re wanting a refreshing beverage before or after your workout, you should stack it with some other supps.

Although Transparent Labs L-Citrulline doesn’t come with any other bells and whistles, it’s ideal for those who want a simple product that they can dose as they like. Plus, this product contains no unwanted additives or ingredients.

Best Citrulline Pills: Nutricost L-Citrulline

Who Should Buy Nutricost L-Citrulline

• Anyone who prefers easy-to-consume supplements.
• Athletes who travel often with supplements.
• People on a tight budget will love the price of this supplement. 

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.
• Those who enjoy mixing up their supplements in their favorite shaker bottle will want to opt for a powder. 

For anyone on the go, these third-party tested, gluten-free capsules can help keep you fueled for your workout even when you don’t have time to mix up a powdered drink.

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. For those who are on a strict budget, you’ll love to note that this nitric oxide supp costs less than $0.20 per serving. 

If you are in the market for a capsulated citrulline supplement, then Nutricost L-Cirtulline is certainly a top-tier consideration, as long as you’re not vegetarian. 

Best Citrulline for Vegans: Doctor’s Best L-Citrulline

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.
• Those on a budget will be happy with this price point.

Who Shouldn’t Buy Doctor’s Best L-Citrulline

• Anyone anxious about secure packaging during delivery.
• Customers who prefer a flavored supplement will want to look at other choices on this list. 
• Those who prefer pill formulation will have to check elsewhere as this is a powder.

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. 

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.

The quality of this supplement is almost overshadowed by its incredible price point. This supplement costs less than $0.30 per serving making it high quality and affordable for almost any budget. This is an unflavored powder and contains no artificial colors, fillers, sweeteners, or dyes. 

If you’re looking for a vegan-friendly product, this product’s label is fact-checked and completely free of animal products. As a bonus, it’s also free of artificial ingredient and fillers, making this a pure third-party tested supplement. 

The Benefits of Citrulline

Citrulline is an amino acid that appears to increase plasma levels of arginine and ornithine, improving nitric oxide metabolism. (2)(3)(4) 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. (5)(6)

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. (7)(8)(9)(10)(11) Citrulline itself has been seen in a few studies to improve power output and time to fatigue in cyclists and tennis players. (12)(13)

As for dosing, research in the International Journal of Cardiology and the European Journal of Applied Physiology found that a dose of five or so grams of citrulline may increase nitric oxide production and blood flow. (14)(15)

How We Chose the Best Citrulline Supplements

There are a handful of categories that we used to weed out the best of the best when it comes to citrulline supplementation. Based on our supplement testing methodology, here is how we built this list.

Dosage vs. Cost

This is a pretty straightforward ranking system in our eyes. 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 a 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 consumer’s 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, high-quality supplements. Once one competitive option gets third-party tested and can verify the purity of its 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 weigh 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 vegans and 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.

How Much Does Citrulline Cost?

Citrulline happens to be one of the least expensive supplements, and alongside fan-favorite creatine, it is one of the most affordable supplements to add to your supplement stack. The average price per serving on this list comes out to around $1.14, but it’s good to keep in mind that this list includes a wide variety of different types of citrulline supplements.

Best Pre-Workout for Citrulline	Transparent Labs BULK Black	$54.99 $1.83 per serving
Best Citrulline for Nitric Oxide Production	Transparent Labs L-Citrulline	$17.99 $0.15 per serving
Best Citrulline Pills	Nutricost L-Citrulline	$18.00 $0.20 per serving
Best Citrulline for Vegans	Doctor’s Best L-Citrulline	$18.59 $0.28 per serving

When looking at the supplements that are purely citrulline without many additional ingredients, you’ll find each supplement costs less than $1.00 per serving. When you look at the supplements that include citrulline among a lineup of other ingredients — such as a pre-workout — you’ll find they get exponentially more expensive and can cost over $2.00 per serving. The robust nature of those supplements will drastically change the price. Regardless of your budget, there is likely a good fit for your needs on this list.

Citrulline vs. Citrulline Malate

Citrulline is a 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 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 improving recovery, and another found it to postpone exercise fatigue in handball players. (16)(17) Other studies have found no effect on performance or muscle soreness. (18)(19)

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.

When Should I Take Citrulline?

Citrulline is a common pre-workout ingredient for a reason. You’ll likely receive the most benefit by taking your citrulline supplement about 30 minutes before your workout. 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. 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 it over time. 

What to Consider Before Buying Citrulline?

Since citrulline can come in varying packages, it’s important to consider what ingredients you want with your citrulline (if any), the form of citrulline you prefer, and the price range you want to stick to. 

Ingredients

There are many citrulline supplements that contain just citrulline, but there are also some supplements that contain other nitric oxide-producing ingredients or pre-workout ingredients. In addition to that, citrulline can sometimes come in the form of citrulline malate, which includes malic acid in addition to the citrulline to potentially help with absorption and stamina. 

Before deciding which supplement you’re going to buy, consider the ingredients you want along with your citrulline (if any) — this will help guide you to the proper pick on this list. 

Form

Citrulline can come in both powder and pill form. As far as powder goes, you can find both flavored and unflavored powders. If it’s a powder you prefer, you’ll want to consider if you’ll be taking your citrulline in an already-flavored beverage or just plain water. If you’re just taking it in water, a flavored powder will probably be more appealing to you than an unflavored one. And if you’re drinking your citrulline in flavored water, with your greens powder, or with juice, unflavored will be your best bet. 

Capsules can be convenient for those who don’t want to have to mix a powder. But note, many capsule citrulline supplements require more than just a couple of capsules per dose. Consider your daily schedule and personal preferences on pill-taking before deciding which form to go with. 

Price

Citrulline prices have a wide range due to the different ingredients you may find in addition to your citrulline. If you’re buying plain citrulline, you’re likely going to be spending much less than if you’re buying citrulline within a pre-workout supplement, which will contain far more ingredients. Before deciding you want the supplement with the most helpful ingredients in addition to your citrulline, set a price limit for yourself — citrulline alone may be the most budget-friendly option. 

Final Word

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 potentially improve circulatory health or erectile dysfunction), it’s important to speak with a physician before starting a new supplement regimen.

After you’ve done your due diligence, you’ll want to consider the ingredients, the form you prefer, and your price range before hitting the market. After that, allow this list to guide you through the rest.

FAQs

References

1. Examine.com. (2023, January 12). Citrulline health benefits, dosage, safety, side-effects, and more: Supplements. Examine. Retrieved January 18, 2025, from https://examine.com/supplements/citrulline/
2. 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.
3. 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.
4. 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.
5. Moncada S, et al. The discovery of nitric oxide as the endogenous nitrovasodilator. Hypertension. 1988 Oct;12(4):365-72.
6. Cormio L, et al. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction. Urology. 2011 Jan;77(1):119-22.
7. 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.
8. 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.
9. 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.
10. Murphy M, et al. Whole beetroot consumption acutely improves running performance. J Acad Nutr Diet. 2012 Apr;112(4):548-52.
11. Lansley KE, Winyard PG, Fulford J, Vanhatalo A, Bailey SJ, Blackwell JR, DiMenna FJ, Gilchrist M, Benjamin N, Jones AM. 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. doi: 10.1152/japplphysiol.01070.2010. Epub 2010 Nov 11. PMID: 21071588.
12. 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.
13. 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.
14. 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.
15. 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.
16. 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.
17. 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.
18. 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.
19. 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).