What Is Citrulline? 

Citrulline (L-Citrulline) is a naturally occurring amino acid that plays an important role in nitric oxide production and healthy blood circulation. Unlike most amino acids, citrulline is not used to build proteins. Instead, it helps the body produce arginine, another amino acid that is converted into nitric oxide—a molecule that relaxes blood vessels and supports healthy blood flow. 

Because of its role in circulation and exercise performance, L-Citrulline is commonly found in performance pouches, pre-workout supplements, sports nutrition products, and endurance formulas. It is one of the most widely studied ingredients used to support workout performance and nitric oxide production. 

How Does Citrulline Work? 

After consumption, L-Citrulline is absorbed into the bloodstream and converted by the kidneys into L-arginine. Arginine is then used to produce nitric oxide (NO), a naturally occurring signaling molecule that helps relax blood vessels and improve circulation. 

Improved blood flow may increase the delivery of oxygen and nutrients to working muscles during exercise, which is why citrulline is commonly included in pre-workout and performance-focused formulations. 

Unlike arginine supplements, L-Citrulline is absorbed efficiently and bypasses significant breakdown in the liver, allowing it to increase arginine levels more effectively in many individuals. 

Potential Benefits of Citrulline 

Research suggests L-Citrulline may help support: 

While many studies have reported positive results, the magnitude of these benefits varies between individuals, and research is ongoing to better understand optimal dosing and long-term effects. 

Citrulline vs. Citrulline Malate 

There are two common forms of citrulline used in supplements. 

L-Citrulline 

L-Citrulline is the pure amino acid and is the form naturally produced by the body. It has been extensively studied for its ability to increase arginine levels and support nitric oxide production. 

Citrulline Malate 

Citrulline Malate combines L-Citrulline with malic acid, a compound naturally found in fruits such as apples. This form is commonly used in pre-workout supplements and is intended to support both nitric oxide production and cellular energy metabolism. 

Research on Citrulline Malate has shown mixed results, while L-Citrulline currently has more consistent evidence supporting its role in increasing nitric oxide and blood flow. 

Is Citrulline Safe? 

L-Citrulline is generally considered safe and well tolerated when used as directed. 

Clinical studies have used doses ranging from approximately 3 to 15 grams per day with very few reported adverse effects. Compared with arginine, citrulline is often better tolerated and less likely to cause digestive discomfort. 

Some individuals may experience mild side effects, including: 

Anyone who is pregnant, breastfeeding, taking prescription medications, or managing cardiovascular conditions should consult a healthcare professional before using citrulline supplements. 

Natural Sources of Citrulline 

L-Citrulline occurs naturally in several foods, including: 

Although these foods naturally contain citrulline, performance supplements and nicotine-free performance pouches typically provide standardized amounts that are much higher than those obtained from food alone. 

Citrulline in Nicotine-Free Oral Pouches 

L-Citrulline has become a popular ingredient in nicotine-free performance pouches because it complements ingredients that support physical performance. 

Manufacturers commonly combine citrulline with ingredients such as: 

These formulations are designed to support energy, endurance, circulation, and workout performance in a convenient oral pouch format. 

Products That Contain Citrulline 

Citrulline is commonly used in performance-focused products to support nitric oxide production. Brands currently offering products containing Citrulline include: 

Product formulations may change over time. Always check the ingredient list on each product page for the most up-to-date information. 

Frequently Asked Questions 

What is Citrulline? 

Citrulline is a naturally occurring amino acid that helps the body produce arginine and nitric oxide, supporting healthy blood flow and circulation. 

What does Citrulline do? 

Citrulline helps increase nitric oxide production, which may support blood flow, oxygen delivery, exercise performance, and muscular endurance. 

Is Citrulline a stimulant? 

No. Citrulline is not a stimulant and does not contain caffeine or other stimulants. 

Is Citrulline the same as Arginine? 

No. Citrulline and arginine are different amino acids. After consumption, citrulline is converted into arginine inside the body and is often more effective at raising arginine levels than taking arginine directly. 

What's the difference between L-Citrulline and Citrulline Malate? 

L-Citrulline is the pure amino acid, while Citrulline Malate combines citrulline with malic acid. Both are used in sports nutrition products, although L-Citrulline currently has more consistent clinical evidence supporting its effects on nitric oxide production. 

Which products contain Citrulline?