Best L-Citrulline Supplement

If you're among the nearly 50% of Americans trying to lose weight and get in shape, you've likely considered pre-workout supplements. Thousands of brands on the market promise everything from bulking you up to burning fat and boosting metabolism. Some of their products work well, while others amount to little more than snake oil.

L-citrulline and citrulline malate supplements have been shown to enhance athletic performance by boosting the body's nitric oxide production, increasing blood flow, and providing endurance and strength for more strenuous workouts.1 Those effects also offer benefits for certain cardiovascular conditions and, in some cases, may even help treat erectile dysfunction (ED).

We tested the top brands of citrulline supplements and determined clear winners for various goals.

If you don't have time to read our complete guide, here’s a rundown of our top picks below.

At Innerbody Research, we extensively test each health service or product we review, including citrulline supplements. On top of our personal experiences with these products, our team devoted more than 700 hours to reviewing hundreds of research papers about physical and cardiovascular fitness, sexual health, and citrulline’s role in either.

Trying these out for ourselves allows us to relay to you critical factors like taste, mixability, and even efficacy, albeit in a small sample size. It also allows us to speak with confidence to each company’s customer service, shipping logistics, and, where necessary, return procedures.

This guide was also vetted by Jordan Stachel, a Registered Dietitian Nutritionist and a member of Innerbody Research's Medical Review Board. We’ll keep our eyes on the citrulline landscape in the coming weeks and months to keep our recommendations as current as possible.

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions about staying healthy and living healthier lifestyles.

We considered five primary criteria to evaluate our top citrulline supplements: effectiveness, cost, safety, taste, and customer experience. The fact that we tried these supplements for ourselves allows us to speak to taste, which we believe is crucial for a product you’ll likely consume almost daily.

Let’s take a closer look at which products gained an advantage over their competition in each criterion:

Effectiveness

Advantage: Transparent Labs Beast Bulk

Considering that a significant amount of citrulline research and search interest revolves around exercise performance, it makes sense that a pre-workout would end up taking the advantage for effectiveness here. Transparent Labs Beast Bulk delivers a clinically solid 8g of L-citrulline malate, a dose that forms the backbone of most citrulline malate research.18

It also contains betaine anhydrous, Alpha-GPC, and a slew of other ingredients that can improve workout performance (we’ll break each one down in a lower section). It also contains a great source of arginine, an amino acid associated with citrulline. Specifically, citrulline is a precursor to arginine, so having both in a supplement not only increases the total arginine your body can eventually use, but it also offsets the delivery and performance of that arginine, potentially extending the duration of action for your workout boost. In clinical trials like this one from March of 2026, the combination of citrulline and arginine outperformed a placebo and either supplement alone for various workout markers.19

In fact, the arginine source in Beast Bulk is a branded, inositol-stabilized arginine called Nitrosigine. At the dose provided in Beast Bulk, Nitrosigine has been shown to improve energy levels, strength, and recovery when used as a pre-workout ingredient.17

And, between the caffeinated Beast Bulk from Transparent Labs and the stim-free option from Kaged, Transparent Labs offers a more well-rounded formula for blood flow and workout improvement.

Kaged also has a caffeinated version of its Elite pre-workout, but it lacks any form of arginine, let alone Nitrosigine. Kaged’s caffeinate preworkout also contains too much caffeine by our standards, making it fundamentally less suitable for as many people as Beast Bulk, despite containing more citrulline. And Transparent Labs’ inclusion of L-theanine should also help counter any jittery side effects of its caffeine content, making it an even better choice for steady focus in the gym.2

The fact that Transparent Labs uses L-citrulline malate as opposed to L-citrulline on its own actually didn’t play into our recommendations. There’s a pretty fierce debate about which form of citrulline is better, and we’ll go much deeper into this in a dedicated section to the question below. For now, suffice it to say that there should be no meaningful difference between the two, at least per human clinical evidence, so long as doses of citrulline involved are equivalent and meet a threshold for efficacy set in the literature.

Cost

Advantage: Kaged Citrulline Powder

Cost comparisons among L-citrulline supplements aren’t particularly straightforward. Additional ingredients — whether simply malic acid or a slew of pre-workout aids — will impact price significantly. Fortunately, there's enough research support for L-citrulline taken on its own that a standalone L-citrulline supplement makes for an excellent budget pick.

There are many such supplements to choose from, and most offer much better pricing than more complex pre-workouts. Companies that offer bulk quantities are even better for this purpose, and PureBulk takes the cake for cost with its straightforward L-citruline powder. To get the biggest bang for your buck, you can opt for a larger quantity. Though your up-front cost may be higher when buying in bulk from a company like PureBulk, your per-gram cost will be very low.

Here’s a quick per-gram comparison from the top companies offering standalone L-citrulline at a low price:

As you can see, while Bulk Supplements has a slightly lower initial price, its shipping costs are double what PureBulk charges, which translates to meaningful savings over time. And, for the record, both PureBulk and Kaged have better prices for smaller quantities at 250g and 200g, respectively.

Safety

Advantage: Kaged Citrulline Powder

As far as safety is concerned, L-citrulline on its own doesn’t pose too many risks for healthy individuals. Because it’s a precursor to L-arginine, which causes vasodilation and reduces blood pressure, it can pose certain dangers to consumers with cardiovascular conditions or those who take medications that affect their blood pressure.

But those risks aren’t inherent to one brand over another, even comparing L-citrulline and L-citrulline DL-malate. So, how can we award one company higher marks for safety than another? The answer comes down to manufacturing and transparency.

That’s where third-party testing and high manufacturing standards come in, and it’s where Kaged’s status as an Informed Choice-certified product gives it the advantage. An Informed Choice product is one that undergoes rigorous third-party testing for purity and safety, as well as regular manufacturing audits and inspections to ensure adherence to FDA manufacturing guidelines.

Kaged also has an L-citrulline product that’s vegan, non-GMO, and gluten-free. PureBulk is a runner-up here, thanks to its relatively transparent third-party testing. The company posts the test results right on its product page, but there’s no telling what batch they belong to, nor how old they might be.

Taste

Advantage: Transparent Labs

L-Citrulline research typically relies on several grams or more per dose, leading manufacturers to create supplements that come as powders, rather than asking you to take a giant handful of pills to reach effective servings. As such, taste becomes a significant criterion, especially in the context of pre-workouts. L-citrulline on its own is mostly tasteless. L-Citrulline malate has a pleasant sourness to it, not unlike a sour apple flavor — likely due to malic acid’s presence in apples.

But pre-workout drink mixes come in various flavors with additives for sweetness, and they contain so many other active ingredients that their overall taste and mixability can vary significantly.

Across the board, Transparent Labs takes the advantage over its competitors in terms of taste. Not only does it offer more flavors to choose from, but each flavor we’ve tried has been excellent, with moderate sweetness from stevia rather than sucralose. The one downside in the company’s flavor options is that Beast Bulk, our preferred pre-workout from the brand, only comes in one flavor. The good news is that Beast Bulk’s one flavor is outstanding, perhaps our favorite from the company. It’s a sour gummy flavor, reminiscent of gummy worms, but milder and easier to drink.

Customer experience

Advantage: Transparent Labs

We’ve dealt with the companies in this guide and their main competitors on numerous occasions while investigating products and ordering them for ourselves. The overall experience with each is relatively similar, but Transparent Labs has usually caused us the fewest headaches.

For example, we deeply appreciate it when a company subjects its products to third-party testing, but not all companies make the results of that testing available. Transparent Labs and PureBulk both offer those results to the public, but whereas PureBulk displays a test result unconnected to any current lot number, Transparent Labs maintains a database of results that you can find by searching the lot number on any product you receive in the mail.

That little extra bit of simplicity permeates Transparent Labs’ structure. It isn’t perfect (the hours of attendance for its phone support are quite wonky), but it’s better than most and just superior enough to the two other companies in this guide to warrant an advantage here.

The chart below shows how our top recommendations compare in terms of cost, ingredients, and more. Your product choice will mostly depend on your lifestyle, budget, and dietary needs.

These price comparisons are based on single purchases of each product and do not account for subscription plans or bulk purchases, which can often earn more savings.

L-Citrulline is a nonessential amino acid that’s produced in the body but is also available through diet. When you ingest L-citrulline supplements or foods containing L-citrulline, the kidneys transform it into L-arginine, another nonessential amino acid known for increasing nitric oxide production. These compounds benefit heart and blood vessel health and may boost the immune system.

One of the primary reasons people take citrulline supplements is to increase endurance during intense workouts. Others take them to help lower blood pressure or address symptoms of erectile dysfunction.

Some of the likeliest benefits you'll encounter from taking a citrulline supplement include:

L-Citrulline (CIT) is an organic nonessential amino acid once primarily derived from watermelons and now produced through a fermentation process with yeast cultures. It is also naturally produced in the body through endogenous synthesis in the liver and intestines. It is rarely attained from a regular diet (unless you live on a watermelon farm).

Citrulline's primary functions in the body are helping eliminate harmful substances, such as ammonia, through urine, and promoting nitric oxide production and vasodilation.

Studies examining long-term L-citrulline use have demonstrated that supplementation may reduce systolic blood pressure and can reduce diastolic blood pressure at doses greater than or equal to six grams per day.8 Acute use of similar doses has also resulted in positive effects.9 For those at risk of heart disease and hypertension, supplementing citrulline may help prevent the need for medications down the line, though this is a sensitive enough area of your health that you should definitely speak with your doctor before taking it.

Citrulline supplements aid athletic performance by promoting nitric oxide production in the body, increasing the amount of oxygen in your muscle tissues. Nitric oxide modulates:22

• Mitochondrial respiration
• Muscle energy
• Metabolism
• Blood flow

Thus, increasing nitric oxide production can improve endurance and reduce muscle soreness during and after workouts. It can also increase blood flow to the sexual organs, potentially addressing symptoms of erectile dysfunction.

In studies of CIT supplementation in elderly and malnourished rats, researchers showed that those who received supplements gained muscle protein, especially when supplemented with branched-chain amino acids (leucine, valine, and isoleucine) as well.10 More human studies would be useful.

A quick look around the market reveals that the potential range of citrulline doses is extremely wide. At the high end, you’ll see L-citrulline doses around 10g per serving, with the low end dropping down closer to a single gram. That’s an enormous difference for supplements claiming to provide the same benefits, so it’s understandable that you might not know how much of this stuff you should take.

To clarify the picture, we look at the research. Doses used in clinical research are nearly as varied as those used in supplements throughout the market, but there seems to be a consolidation around 6-8g of L-citrulline malate per day.24 That makes a similar dose a very good starting point for most people, and it translates to around 4g-5.3g of L-citrulline (non-malate) per day.

However, a recent study from March of 2026 found that an 8g dose of citrulline malate failed to improve leg press strength or repetitions compared to placebo, while another group taking 12g saw improvements.25 The cohort was all trained individuals, which may be important.

Ultimately, if you’re newer to training, you might be fine with a smaller dose. But if you’re an athlete or a long-time gymgoer, you might need to tritrate up closer to 12g/day.

Before we get into the nitty-gritty, we’ll simply say that there’s no evidence supporting one form of L-citrulline over another, provided the citrulline doses are equivalent. For example, a 5.3g dose of L-citrulline should perform identically well as an 8g dose of 2:1 L-citrulline malate.

So, why all the fuss? Well, citrulline malate (CM) combines L-citrulline with DL-malate (essentially malic acid), a compound derived from apples that may assist in converting food to energy. There’s some evidence that malic acid may offer health benefits of its own, protecting both cardiometabolic health13 and the balance of beneficial microbes in the gut.14 But this is predominantly animal and in vitro research that hasn’t been reproduced in humans.

Malic acid is also less expensive than L-citrulline, cutting costs for manufacturers, consumers, and — importantly — researchers. So, we end up with one mountain of evidence looking into L-citrulline, and a larger one looking into L-citrulline malate.

This 2016 study showed that CM supplementation improved tennis performance in female subjects, specifically improving power and endurance.11 A 2015 study showed that CM supplementation improved muscle performance while having no significant impact on lactic acid levels for advanced weightlifters during repeated bouts of lower-body exercise.12 Meanwhile, a comprehensive review of citrulline studies (without malic acid) found that it meaningfully improved blood pressure markers.

And in 2025, a review dedicated to comparing the two forms declared “there is no apparent difference between LC and CM.”23 But here’s the rub: another recent review discussed discrepancies between many CM label claims and the actual ratio of citrulline to malic acid present.18 The average among companies studied was 1.6:1, despite label claims of 2:1. And most third-party testing ignores this ratio.24

So, we often prefer products with simple L-citrulline in them to those with citrulline malate, if only because we know we can verify the dose we’re recommending. That said, if it’s a company we trust with good third-party testing, like Transparent Labs, we won’t hesitate to recommend a top-tier product that happens to use malate.

L-Citrulline supplements are a great choice for those who are already considered healthy, especially when it comes to cardiovascular health. They’re ideal for those looking to increase exercise performance and decrease recovery time with a single ingredient. They may also provide some relief for men who have sporadic experiences with mild erectile dysfunction.

Serious athletes can also look for pre-workout supplements that contain a significant amount of L-citrulline. These will often also contain caffeine, BCAAs, vitamin complexes, and other components intended to improve exercise performance. Because of this blend of ingredients, many pre-workouts skimp on one or more of each, leading to underdosing and sometimes a lack of efficacy. The pre-workouts we recommend as L-citrulline supplements each contain clinically relevant doses of L-citrulline and other beneficial ingredients.

Who shouldn't use citrulline supplements?

We’ll get into some specific safety concerns below, but there are also various reasons someone might take a citrulline supplement that simply aren’t supported by science, at least not yet. Take, for example, ED. There is certainly evidence that citrulline could help with very mild cases, but if your ED is moderate or severe, it likely won’t do the trick. This is even more true if your ED isn’t blood flow-related.

Citrulline also won’t make you a monster in the gym after a single dose. You shouldn’t take it if you expect to be able to add tremendous amounts of weight to your maximum reps or double the amount of time you spend on a treadmill. You’re setting yourself up for disappointment or injury. More realistically, you can expect moderate improvements in strength, endurance, and recovery — the kind you might not even be able to feel, at least not directly connected to the supplement. Still, over time, using citrulline could get you to a point where you can increase your weight a bit sooner or spend an extra day or two per month in the gym, and that can add up over months and years to meaningful differences.

L-citrulline and citrulline malate supplements are generally safe for healthy individuals, and research has used doses of up to 15g/day without serious adverse effects.15 Like any supplement, even the healthiest individuals might experience some nausea, headaches, or gastrointestinal discomfort when beginning a new regimen. These symptoms typically fade, but if they don’t, you should talk to your doctor.

While healthy individuals should be fine taking L-citrulline supplements, the potential for certain contraindications and cardiovascular effects makes L-citrulline supplements a little more dangerous than some others.

If you’re taking vasodilators or other medications for blood pressure, you should not take citrulline supplements without first consulting your doctor. These supplements can lower blood pressure to dangerous levels when combined with certain medications.

Examples of vasodilators include:

• Alprostadil IV
• Corlopam
• Deponit
• Fenoldopam
• Glyceryl trinitrate transdermal
• Hydralazine
• Loniten
• Minitran

Other medications that interact with citrulline supplements include those prescribed for erectile dysfunction, such as:

• Tadalafil (Cialis)
• Sildenafil (Revatio, Viagra)
• Vardenafil (Levitra, Staxyn)
• Stendra

Pregnant or nursing individuals should also avoid citrulline supplements. Anyone with a chronic medical condition or those taking medications should talk to their doctor before beginning any new dietary supplement.

It would be wise for even healthy people to get their blood pressure checked before taking L-citrulline and to make an appointment to talk to their doctors about any and all cardiovascular issues they may have experienced, just to rule out any possible underlying risks.

Best overall and best pre-workout (without caffeine)

Kaged sells plain fermented L-citrulline supplements in addition to more complex pre-workout options. Kaged Fermented L-Citrulline is decidedly the simpler product. It contains only L-citrulline with no additives of any kind. That’s why it can claim to be vegan, gluten-free, and non-GMO. It offers a nice entry point to L-citrulline for anyone not interested in complex formulas or making large bulk purchases of plain powder.

The suggested serving size is a little low, at just 2g, but that’s also the capacity of the scoop. Since most citrulline research uses doses that are divisible by two, that makes this scoop especially useful for anyone looking to titrate for their own purposes.

The company's Pre-Workout Elite pre-workouts are available caffeinated or stim-free — again, similar to Transparent Labs — and it’s the caffeine-free Elite that earns top marks from us as a stim-free pre-workout with a focus on L-citrulline.

Here’s a look at the ingredients in Kaged Pre-Workout Elite:

With such a high dose of L-citrulline and an impressive amount of creatine, the Pre-Workout Elite formula has nearly everything you might want in a pre-workout. The caffeinated version adds nearly 400mg of caffeine, which is more than we’d recommend in a pre-workout unless you were planning to make it your sole source of caffeine for the entire day.

Taste and mixability

Another parallel between Kaged and Transparent Labs is that both are companies on this list that offer flavored drinks containing L-citrulline. The difference is that Kaged uses sucralose as a sweetener. Our testers typically find that sucralose imparts more of an artificial aftertaste in anything it sweetens, and Kaged’s products were no exception. (If you like and use Splenda a lot, you might prefer the flavor of Kaged, though.)

There’s also some evidence that sucralose may pose health risks. It’s been linked both to increased cancer risk and to disturbances in the gut microbiota.26

Kaged Pre-Workout Elite Stim-Free is available in the following flavors:

• Cherry
• Caribbean Sunrise
• Orange Mango
• Strawberry Lemonade
• Fruit Punch

Kaged and Transparent Labs pre-workouts mix with the same relative efficiency, almost dissolving into plain water with a vigorous stir and going the rest of the way in a shaker cup. Neither produced any meaningful clumping or sediment, and both offered a good mouthfeel.

Pricing

Since Kaged has several L-citrulline products and a subscription savings program, we thought a simple chart could clarify what you might spend on any of them:

A subscription offers savings on the product and unlocks free shipping, but that only really matters for the Fermented Citrulline, as the two pre-workout options listed here cost more than the $35 free shipping threshold.

Kaged gives you 30 days to initiate a return, but it won’t accept returns on products that are more than halfway consumed. How exactly the returns team measures out the product to determine this isn’t obvious, but this shouldn't pose too much of an issue for L-citrulline supplements. L-Citrulline consumption should produce palpable results after a short amount of time if it’s going to work for your needs, so you should know whether or not you want to stick with a given product before you get halfway through its contents. With that in mind, this ends up being a superior policy to those from either PureBulk or Transparent Labs.

Best pre-workout (caffeinated), and best tasting

Transparent Labs previously offered two very appealing supplements containing L-citrulline DL-malate — its BULK and STIM-FREE pre-workouts. You might expect that Bulk and Stim-Free would be essentially the same, with the Stim-Free excluding the caffeine and perhaps adding something to make up for it. But, strangely, Stim-Free is a significantly different formula, with a few extra corners cut than just the caffeine. To be fair, the company added ElevATP and choline to the picture, the latter of which can help provide the focus others would rely on caffeine to create.16 But it still doesn’t feel like enough of a formula to justify it over a caffeinated alternative if you can handle the caffeine (if not, we recommend Kaged).

That’s why Bulk has generally been our preferred pre-workout from the company, at least until Beast Bulk arrived. With Beast Bulk, Transparent Labs took the Bulk formula and added one of our favorite nitric oxide precursors, inositol-stabilized arginine silicate, specifically the branded form called Nitrosigine. Nitrosigine has been shown to deliver benefits for strength, endurance, and recovery at the 1.5g dose used in Beast Bulk.17 And Transparent Labs added it without raising the price compared to regular Bulk.

Here’s a side-by-side look at some key ingredients in Bulk and Beast Bulk from Transparent Labs, with Pre-Workout Elite thrown in for added context:

While there are various important differences between Transparent Labs and Kaged here, check out that caffeine difference. For reference, the average espresso contains around 85mg of caffeine. Bulk and Beast Bulk give you a little more than a double-shot. Kaged essentially provides four shots of espresso in every serving. If you add that to even a modest morning coffee routine, you’ll be consuming what could be, for many people, way too much caffeine.

Taste and mixability

Transparent Labs’ flavored drinks mix pretty well into water — not as well as simple L-citrulline, but better than some competitors in the space. Stirring the powder into a glass of water resulted in only a small amount of clumping. Escalating that stir to a mix in a shaker cup took care of those clumps.

Thanks to being sweetened with stevia, Transparent Labs pre-workouts have a mild, fruity taste that doesn’t result in the kind of cringe you’d get with more artificial flavors and sweeteners. And, despite coming in only one flavor, the Sour Gummy delivered by Beast Bulk was our team’s universal favorite, with just enough sweet and sour flavor to carry the day.

Each is available in the following flavors:

Pricing

Transparent Labs offers its L-citrulline-based supplements as one-time purchases or as part of a subscription program. Its pre-workouts are also available within larger stacks built around targeted goals like weight loss or muscle building. For now, let’s look at how the pricing compares for L-citrulline supplements as one-time or subscription purchases.

Shipping from Transparent Labs starts at $7.99, but it’s free on subscription orders and on orders over $99. That’s a pretty high threshold for free shipping compared to the field. PureBulk offers free shipping once you get over $49, and Kaged offers it on orders over $35.

Best for bulk purchasing

PureBulk is a supplement marketplace that offers large quantities of its supplements to bulk buyers and smaller sizes for regular customers. Its L-Citrulline delivers a plain, well-researched ingredient at a very reasonable price. Its effective form of L-citrulline is free of the following:

• Dairy
• Soy
• Yeast
• Sugar
• Gluten
• Corn
• Additives

Possibly the least convenient thing about it is that it doesn’t come with a scoop, which makes measuring out a dose annoying until you get to the point where you can eyeball it.

Taste and mixability

Any L-citrulline supplement that comes to you unflavored and without many other ingredients is going to mix well with water. After a brief stir, it all but dissolves completely. On the taste side, there is almost nothing to detect. If you don’t like drinking plain water, you won’t like plain water with L-citrulline in it. But because it has next to no flavor, you can add it to just about anything.

Pricing

PureBulk offers its L-Citrulline DL-Malate in five sizes, each of which reduces the cost per gram as you move up the ladder. Here’s how it breaks down:

To be clear: there are significant savings per gram between the 500g and 1kg levels, but we rounded down to $0.04 for the 500g level and up to $0.04 for the 1kg level.

You can get free shipping from PureBulk on orders over $49, but none of these price levels reach that threshold. That means you’ll also incur a shipping fee of around $5.

PureBulk has a strangely limited return policy regarding opened products. It certainly doesn’t amount to a money-back guarantee, but it is something. For an unspecified amount of time, the company will let you return a product. If it’s unopened, and you haven’t waited so long that the product has expired or come close to it, you’ll probably get a full refund minus shipping charges. If it is opened, the company will only refund you the value of that product’s smallest available quantity.

For example, you could order a 1kg bag to save on shipping, and if you tried to return it after using it a few times, you’d only be eligible to receive a refund for the value of a 100g bag, which is the smallest available quantity. That’s a loss of more than $35 before you account for return shipping. We’d like to see a more forgiving policy here, but it isn’t that unusual for suppliers in this space to be strict. No product on this list offers a proper money-back guarantee.