Citruilline Malate
Also known as: CM, L-Citrulline Malate, Citrulline Malate
Overview
Citrulline Malate (CM) is a compound combining L-citrulline, a non-essential amino acid found in foods like watermelon, with malate, an intermediate in the Krebs cycle. Primarily used as an ergogenic aid in sports nutrition, CM aims to enhance exercise performance, reduce muscle soreness, and accelerate recovery. It is believed to exert its effects by increasing nitric oxide (NO) production, which promotes vasodilation and improves blood flow, and by supporting energy production through malate's role in cellular respiration. Research on CM is moderately mature, with several systematic reviews and meta-analyses supporting its benefits, particularly in healthy young adults engaged in resistance or endurance training. It is generally considered safe with a good safety profile at typical dosages.
Benefits
Citrulline Malate offers several evidence-based benefits for exercise performance and recovery. A 2020 systematic review and meta-analysis indicated that citrulline supplementation significantly reduces post-exercise rating of perceived exertion (RPE) and muscle soreness, with effects most pronounced within 24 hours post-exercise. However, it did not significantly impact blood lactate levels. Another 2021 systematic review and meta-analysis specifically on acute CM supplementation before strength training found a statistically significant increase in total repetitions performed during resistance exercise, demonstrating improved muscular endurance. While some studies suggest improved physical endurance and reduced fatigue, effects on anaerobic performance are less consistent. These benefits are primarily observed in healthy young adults, with moderate effect sizes for RPE and muscle soreness reduction, and modest but significant improvements in repetitions.
How it works
Citrulline Malate primarily works by increasing nitric oxide (NO) production and supporting cellular energy metabolism. Upon ingestion, L-citrulline is converted to L-arginine in the kidneys, which then serves as a substrate for nitric oxide synthase (NOS) enzymes. This leads to increased NO production, promoting vasodilation and enhancing blood flow to working muscles. Improved blood flow facilitates better oxygen and nutrient delivery while aiding in waste product removal, thereby reducing fatigue and improving performance. Malate, the other component of CM, is an intermediate in the Krebs cycle, suggesting it may contribute to ATP production and overall energy metabolism, further supporting exercise capacity and recovery. CM is well absorbed orally, and citrulline bypasses hepatic metabolism, making it more effective than arginine supplementation at increasing plasma arginine levels.
Side effects
Citrulline Malate is generally considered safe, with clinical trials reporting no serious adverse effects at typical dosages. The most commonly reported side effect, though rare and mild, is gastrointestinal discomfort in some individuals. No consistent uncommon or rare side effects have been documented in high-quality studies. Regarding drug interactions, no significant interactions have been reported. However, due to its vasodilatory effects, caution is advised when co-administering CM with medications that affect blood pressure. There are no established contraindications, but individuals with hypotension should exercise caution. Data on CM use in elderly, pregnant, or clinical populations is limited, so its safety profile in these groups is not well-established.
Dosage
The minimum effective dose for Citrulline Malate typically ranges from 6 to 8 grams, taken approximately 30-60 minutes before exercise. This acute pre-exercise timing is common for performance benefits. Some protocols also suggest daily supplementation for sustained recovery benefits. The maximum safe dose reported in trials is up to 10 grams per day. CM is commonly available in powder form, mixed with water, but capsules are also used. For optimal absorption, it may be beneficial to take CM on an empty stomach. There are no specific cofactors required for its efficacy. Different dosages may be considered for specific purposes, but the 6-8 gram range is most consistently supported for acute performance enhancement.
FAQs
Does citrulline malate improve strength or endurance?
Evidence supports modest improvements in muscular endurance (increased repetitions) and reduced perceived exertion, but its effects on maximal strength are less clear.
Is it safe to take daily?
Yes, daily supplementation with Citrulline Malate at recommended doses (up to 10 grams) appears to be safe for most healthy individuals.
When should I take it?
For optimal performance benefits, it is typically recommended to take 6-8 grams of Citrulline Malate 30-60 minutes before exercise.
How soon will I see results?
Acute effects on exercise performance, such as reduced perceived exertion and muscle soreness, can be observed within 24 hours post-exercise.
Is it better than arginine?
Citrulline Malate is generally considered more effective than arginine supplementation at increasing plasma arginine levels and is often better tolerated due to bypassing hepatic metabolism.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7749242/ – This systematic review and meta-analysis investigated the effects of citrulline supplementation on exercise performance and recovery. It concluded that citrulline significantly reduces post-exercise rating of perceived exertion and muscle soreness within 24 hours but found no significant effect on blood lactate levels. The study highlighted heterogeneity in research designs but maintained a high quality assessment.
- https://pubmed.ncbi.nlm.nih.gov/34010809/ – This systematic review and meta-analysis focused on acute citrulline malate supplementation and its impact on strength training performance. It found a significant increase in total repetitions performed during resistance exercise, indicating improved muscular endurance. The study was rated as high quality due to rigorous inclusion criteria and statistical analysis.
- https://www.journalofexerciseandnutrition.com/index.php/JEN/article/view/149 – This randomized controlled trial examined the effects of acute citrulline malate supplementation on anaerobic performance in healthy young adults. It reported no significant improvement in anaerobic performance. While well-controlled, the study's findings were limited in scope and generalizability, leading to a moderate quality assessment.