What Is The Difference Between L Citrulline And Citrulline Malate

L-citrulline and citrulline malate are both popular supplements among athletes and health-conscious individuals, but they are often confused due to their similar names and related benefits. While they share a common foundation, the specifics of their chemical composition and effects on the body differ significantly. These differences can influence which supplement might be best suited for your health and performance goals.

L-citrulline is an amino acid that the body converts into another amino acid called L-arginine and a chemical called nitric oxide. These compounds are crucial for heart and blood vessel health, immunity, and other body functions. Citrulline malate combines L-citrulline with malic acid, enhancing its effects, particularly in energy production during exercise. This combination makes citrulline malate especially favored for those engaging in high-intensity exercise.

The decision between L-citrulline and citrulline malate should depend on specific health goals, preferred types of physical activity, and individual body responses. Both supplements promise enhanced nitric oxide production, yet the presence of malic acid in citrulline malate offers added benefits in energy output and potentially greater endurance. Understanding their distinct pathways and impacts can guide users in making an informed choice tailored to their physiological needs.

Key Definitions

What is L-citrulline?

L-citrulline is an amino acid that plays a key role in the urea cycle, which helps the body eliminate toxic ammonia. It is named after watermelon (Citrullus vulgaris), from which it was first isolated. Unlike some amino acids, L-citrulline is not used to build proteins. Instead, it boosts the production of certain proteins and enzymes that are crucial for maintaining arterial health and blood flow.

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What is Citrulline Malate?

Citrulline malate combines the amino acid L-citrulline with malic acid, a compound found in apples and other fruits. This combination is used primarily to enhance athletic performance and endurance by supporting energy production and delaying the onset of muscle fatigue during intense exercise.

Chemical Composition

Structure of L-citrulline

The chemical structure of L-citrulline consists of an amino group, a carboxyl group, and a side chain that makes it unique among other amino acids. It is a non-proteinogenic amino acid, meaning it does not participate directly in the coding of proteins.

Structure and components of citrulline malate

Citrulline malate is formed by combining one molecule of L-citrulline with one molecule of malic acid. The presence of malic acid in the compound enhances the absorption and utilization of citrulline and plays a crucial role in the Krebs cycle, a key energy-producing process in the body.

Benefits Overview

Health benefits of L-citrulline

  • Boosts nitric oxide production: L-citrulline is converted into another amino acid called L-arginine in the kidneys, which then produces nitric oxide. Nitric oxide helps dilate blood vessels, improving blood flow and oxygen delivery to tissues.
  • Reduces blood pressure: By aiding in the production of nitric oxide, L-citrulline helps lower blood pressure in people with pre-existing hypertension.
  • Enhances athletic performance: Increased blood flow can improve oxygen uptake by muscles during exercise, thus enhancing performance and reducing fatigue.
  • Supports immune function: The improved blood flow also helps in better nutrient delivery and waste removal, which can bolster the immune system.

Health benefits of citrulline malate

  • Enhances energy production: Malic acid is a vital component of the Krebs cycle, helping to generate cellular energy efficiently. This is particularly beneficial during prolonged physical activity.
  • Reduces fatigue and muscle soreness: Citrulline malate helps remove ammonia from the blood, a compound that can cause muscle fatigue. It also reduces the buildup of lactic acid in muscles during exercise.
  • Improves muscle recovery: By enhancing nitric oxide production and reducing harmful metabolites, citrulline malate can accelerate muscle recovery following intense exercise.

Mechanism of Action

How L-citrulline works in the body

L-citrulline bypasses the liver when it’s absorbed and is transported directly to the kidneys, where it is converted into L-arginine. This process is crucial for:

  • Enhancing synthesis of nitric oxide: Nitric oxide acts as a vasodilator, improving circulation and oxygen delivery to muscles.
  • Removing waste products: Effective removal of ammonia and other toxic byproducts of metabolism helps improve endurance and reduce fatigue.
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How citrulline malate works

The action of citrulline malate in the body is twofold:

  • Boosts nitric oxide production: Like L-citrulline, it helps in the conversion process to L-arginine, enhancing the body’s nitric oxide capability.
  • Participates in energy cycles: Malic acid, an integral part of citrulline malate, enters the Krebs cycle, contributing to the energy reservoir needed for sustained physical performance.

Usage in Supplements

Common uses of L-citrulline in supplements

L-citrulline is widely utilized in dietary supplements aimed at enhancing vascular health and sports performance. Here are its primary applications:

  • Pre-workout formulas: Often found in pre-workout mixes to enhance blood flow, which can lead to improved exercise performance and increased muscle pump.
  • Heart health supplements: Used to support cardiovascular function due to its ability to increase nitric oxide production.
  • Recovery aids: Included in recovery supplements to help reduce muscle soreness after intense exercise.

Common uses of citrulline malate

Citrulline malate is particularly favored in sports nutrition for its dual role in boosting performance and recovery:

  • Endurance supplements: Popular in formulations aimed at endurance athletes to help reduce fatigue and enhance energy production.
  • Muscle recovery supplements: Used to accelerate the removal of ammonia and lactate from muscles, thus speeding up recovery times post-exercise.

Efficacy in Performance

Impact on athletic performance

Both L-citrulline and citrulline malate have been studied for their potential to enhance athletic performance:

  • L-citrulline: Studies show that L-citrulline can significantly improve strength, aerobic performance, and muscle endurance by enhancing vasodilation and consequently improving blood flow.
  • Citrulline malate: Research indicates that citrulline malate not only improves power output but also increases the rate of ATP production during exercise and the rate of phosphocreatine recovery after exercise.

Comparison of effects on endurance and recovery

  • Endurance: Citrulline malate is often preferred for endurance activities because it helps reduce the perception of fatigue and increases ATP production.
  • Recovery: Both supplements are effective in reducing muscle soreness. However, citrulline malate might have the edge due to its role in flushing out ammonia and lactate faster.

Side Effects

Known side effects of L-citrulline

L-citrulline is generally well tolerated, but it can cause some side effects, especially when taken in large doses:

  • Digestive issues: Such as stomach discomfort, heartburn, or diarrhea.
  • Changes in blood pressure: It can lower blood pressure, which is generally beneficial but can be a concern for people with already low blood pressure.
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Known side effects of citrulline malate

Citrulline malate shares some side effects with L-citrulline, with a few additions:

  • Stomach upset: Particularly when taken on an empty stomach.
  • Palpitations: Rarely, some users may experience heart palpitations, likely due to increased heart workload from enhanced blood flow.

Dosage Recommendations

Recommended dosages for L-citrulline

For different uses, the following dosages are suggested based on scientific research:

  • Exercise performance: 6–8 grams of L-citrulline 30 to 60 minutes before exercise.
  • Cardiovascular health: 3–4 grams daily.

Recommended dosages for citrulline malate

Dosage can vary depending on the intended use:

  • Pre-workout for enhanced performance: 8–10 grams of citrulline malate about an hour before intense exercise.
  • Recovery: 5 grams post-workout.

Popularity Trends

Trends in the use of L-citrulline

  • Growing interest in nitric oxide supplements: L-citrulline’s role in boosting nitric oxide has increased its popularity, especially among older adults and athletes.
  • Research-backed benefits: As more studies confirm its health benefits, its use in clinical settings and over-the-counter supplements has grown.

Trends in the use of citrulline malate

  • Preferred by athletes: Its dual benefits for performance and recovery make it a staple in sports nutrition.
  • Innovative product developments: New formulations and combination supplements are frequently emerging, broadening its market reach.

Frequently Asked Questions

What is L-citrulline?

L-citrulline is a non-essential amino acid found naturally in some foods and also available as a supplement. The body transforms L-citrulline into L-arginine and nitric oxide, which are vital for heart health, widening of blood vessels, and improving blood flow.

What is citrulline malate?

Citrulline malate is a compound that combines L-citrulline with malic acid. This supplement is often used to enhance athletic performance and endurance, as malic acid plays a key role in energy production under aerobic conditions.

How does L-citrulline enhance performance?

L-citrulline improves performance by increasing nitric oxide production in the body. This expansion of nitric oxide helps improve blood flow and oxygen delivery to muscles during physical activity, thus enhancing athletic performance and reducing fatigue.

How is citrulline malate different from L-citrulline in terms of benefits?

Citrulline malate combines the benefits of L-citrulline with the energy-enhancing properties of malic acid. This makes it particularly effective for improving both endurance and power output during prolonged or high-intensity exercise.

Can L-citrulline or citrulline malate help with muscle recovery?

Yes, both supplements can aid in muscle recovery. By improving blood flow, they help reduce muscle soreness and accelerate recovery processes after workouts.


Choosing between L-citrulline and citrulline malate involves understanding each supplement’s unique benefits and how they align with your personal health and fitness goals. While L-citrulline primarily boosts nitric oxide production for cardiovascular health and endurance, citrulline malate enhances this with increased energy production capabilities, making it ideal for those engaged in more intense physical activities. Both supplements offer significant benefits, and the choice should be based on specific needs, preferences, and responses to supplementation. Prioritizing what aligns best with your objectives will guide you to the optimal choice for enhancing your health and performance.

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