Citrulline Malate vs L-Citrulline: Which is the Best Form of Citrulline?

Citrulline supplements have gained popularity in the fitness and health community for their potential benefits in enhancing performance and overall well-being. This article explores the two primary forms of citrulline: Citrulline Malate (CM) and L-Citrulline (LC). Understanding their differences and benefits can help you make an informed decision about which form is best suited for your needs.

Understanding Citrulline

Citrulline is a naturally occurring amino acid found in foods such as watermelon, cucumbers, and other melons. It plays a crucial role in the urea cycle, helping to detoxify ammonia and convert it into urea, which is then excreted from the body. Citrulline is also a precursor to arginine, an amino acid that contributes to the production of nitric oxide (NO), a compound that helps relax blood vessels and improve blood flow.

Citrulline Malate (CM)

Composition and Unique Features

Citrulline Malate is a compound that combines citrulline with malic acid, a substance found in many fruits and involved in the Krebs cycle, which is essential for energy production. The combination of citrulline and malate is believed to provide synergistic benefits, particularly for athletic performance.

Mechanism of Action

Citrulline Malate works by increasing citrulline levels in the blood, which in turn boosts arginine levels and enhances nitric oxide production. The addition of malate may further enhance energy production by aiding the Krebs cycle, potentially improving endurance and reducing fatigue.

Benefits Supported by Research

Research suggests that Citrulline Malate can enhance athletic performance by increasing ATP production ¹, reducing muscle fatigue, and improving endurance. Studies have shown that CM can reduce muscle soreness after intense exercise, making it a popular choice for athletes looking to speed up recovery.

Typical Dosages and Forms Available

Citrulline Malate is typically available in powder form and is commonly taken in doses ranging from 6 to 8 grams per day. Some pre-workout supplements also include CM as part of their formula.

L-Citrulline (LC)

Composition and Unique Features

L-Citrulline is the pure form of citrulline, without any additional compounds. It is directly involved in the nitric oxide production pathway and is primarily valued for its ability to boost arginine levels and enhance blood flow.

Mechanism of Action

L-Citrulline works by increasing the concentration of citrulline in the bloodstream ², which then converts to arginine and subsequently to nitric oxide. This process helps dilate blood vessels, improving circulation and potentially enhancing exercise performance and cardiovascular health.

Benefits Supported by Research

Studies indicate that L-citrulline can improve nitric oxide levels more effectively than direct arginine supplementation ³ due to better absorption and utilization by the body. It is known to enhance blood flow, support cardiovascular health, and improve exercise performance by reducing fatigue and increasing stamina.

Typical Dosages and Forms Available

L-Citrulline is commonly available in both powder and capsule forms, with typical dosages ranging from 3 to 6 grams per day. It is often included in pre-workout supplements, either on its own or in combination with other performance-enhancing ingredients.

Comparative Analysis: Citrulline Malate vs L-Citrulline

Effectiveness in Enhancing Athletic Performance

Both Citrulline Malate and L-Citrulline have been studied for their effects on athletic performance, with research indicating benefits in different areas. Citrulline Malate is particularly noted for its ability to reduce muscle soreness and fatigue post-exercise, which can contribute to improved overall performance in endurance and strength training. L-Citrulline, on the other hand, has shown significant benefits in boosting nitric oxide levels, leading to enhanced blood flow and improved exercise capacity.

Impact on Muscle Soreness and Recovery

Citrulline Malate has a distinct advantage when it comes to reducing muscle soreness. Studies suggest that the malate component helps buffer lactic acid buildup ¹, which is a primary cause of muscle soreness. As a result, athletes using CM often report quicker recovery times and less post-exercise discomfort compared to those using L-Citrulline.

Influence on Nitric Oxide Production

L-Citrulline is highly effective in increasing nitric oxide levels in the body. This is due to its superior bioavailability and conversion efficiency to arginine, which directly stimulates nitric oxide production. Enhanced nitric oxide levels lead to better vasodilation, improved blood flow, and increased delivery of oxygen and nutrients to muscles during exercise.

Endurance and Strength

Both forms of citrulline can positively impact endurance and strength, though they do so through slightly different mechanisms. Citrulline Malate’s ability to enhance ATP production and reduce fatigue contributes to better endurance during prolonged activities. L-Citrulline’s role in improving blood flow can enhance muscle oxygenation, which supports sustained performance and strength during high-intensity workouts.

Dosage Efficiency

When comparing the effective dosages of Citrulline Malate and L-Citrulline, it’s important to consider their respective efficacies and cost-effectiveness. Citrulline Malate typically requires higher doses (6-8 grams) to achieve its benefits, while L-Citrulline can be effective at lower doses (3-6 grams). This difference in dosing can impact cost and convenience, with L-Citrulline often being more economical due to the smaller required doses.

Additional Health Benefits

Beyond athletic performance, both forms of citrulline offer broader health benefits. Citrulline Malate’s enhancement of the urea cycle can aid in detoxifying ammonia and improving overall metabolic function. L-Citrulline’s impact on nitric oxide production supports cardiovascular health by promoting healthy blood pressure and improved circulation.

Side Effects and Safety

Common Side Effects

Both Citrulline Malate and L-Citrulline are generally well-tolerated by most individuals. However, some users may experience mild side effects such as stomach discomfort, nausea, or diarrhea, particularly at higher doses. These side effects are usually temporary and can be minimized by adjusting the dosage.

Safety Profiles

Citrulline supplements have been extensively studied and are considered safe for most people when taken within recommended dosages. It is important to follow the dosage guidelines provided by the manufacturer and consult with a healthcare professional if you have any underlying health conditions or are taking other medications.

Recommended Precautions and Contraindications

Individuals with certain health conditions, such as low blood pressure or cardiovascular diseases, should exercise caution when using citrulline supplements due to their effects on blood flow and blood pressure. Pregnant or breastfeeding women should also consult with a healthcare provider before starting any new supplement regimen.

Choosing the Right Form for Your Needs

Factors to Consider

When deciding between Citrulline Malate and L-Citrulline, it is important to consider your specific fitness goals, health concerns, and personal response to each supplement. Factors such as desired performance outcomes, tolerance, and budget can all influence your choice.

Recommendations Based on Different Scenarios

• For Endurance Athletes: Citrulline Malate may be more beneficial due to its ability to reduce muscle soreness and improve energy production, enhancing endurance over prolonged periods.
• For Strength Athletes: L-Citrulline’s effectiveness in boosting nitric oxide and improving blood flow can support better strength performance and recovery during high-intensity workouts.
• For General Health and Wellness: Both forms offer significant health benefits, but L-Citrulline may be preferred for its cardiovascular advantages and lower effective dosages.

Conclusion

In summary, both Citrulline Malate and L-Citrulline have unique benefits that can support athletic performance and overall health. Citrulline Malate is particularly effective for reducing muscle soreness and enhancing endurance, while L-Citrulline excels in boosting nitric oxide levels and improving blood flow. The best choice depends on your specific needs and goals, and it’s always a good idea to consult with a healthcare professional before starting any new supplement regimen.

Citrulline Malate vs L-Citrulline Review Comparison Table

References

1. Gough, L. A., Sparks, S. A., McNaughton, L. R., Higgins, M. F., Newbury, J. W., Trexler, E., Faghy, M. A., & Bridge, C. A. (2021). A critical review of citrulline malate supplementation and exercise performance. European Journal of Applied Physiology, 121(12), 3283-3295. https://doi.org/10.1007/s00421-021-04774-6[↩][↩]
2. Gonzalez, A. M., & Trexler, E. T. (2020). Effects of citrulline supplementation on exercise performance in humans: A review of the current literature. Journal of Strength and Conditioning Research, 34(5), 1480-1495. https://doi.org/10.1519/jsc.0000000000003426[↩]
3. Shatanawi, A., Momani, M. S., Al-Aqtash, R., Hamdan, M. H., & Gharaibeh, M. N. (2020). L-Citrulline supplementation increases plasma nitric oxide levels and reduces arginase activity in patients with type 2 diabetes. Frontiers in Pharmacology, 11. https://doi.org/10.3389/fphar.2020.584669[↩]