Phyt02
Also known as: Citrulline, L-2-amino-5-ureido-pentanoic acid, Citrullus lanatus (watermelon extract), Citrulline malate, L-Citrulline
Overview
L-Citrulline is a non-essential amino acid naturally occurring in foods such as watermelons, cucumbers, and some melons. It is synthesized in the body as part of the urea cycle, which is crucial for the detoxification of ammonia. L-Citrulline supplementation is primarily geared towards enhancing blood flow, lowering blood pressure, and optimizing exercise performance, especially during endurance activities. Significant evidence supports its role in the nitric oxide (NO) biosynthetic pathway, leading to vasodilation and improved blood flow. Although numerous studies highlight potential benefits, the maturity of the research remains moderate, often yielding mixed results. Chronic supplementation appears to be more beneficial, particularly among untrained individuals or those engaging in low-level athletic activities, compared to trained athletes who may not experience the same degree of effect.
Benefits
The evidence-based benefits of L-Citrulline supplementation include enhanced endurance performance and improved muscle oxygenation, particularly following long-term use of 7-16 days at doses ranging from 3.4-6 g/day. A systematic review noted negligible to small effect sizes for acute supplementation on aerobic performance metrics. In a 7-day trial, doses of 2.4 g/day and 6 g/day exhibited notable improvements in performance metrics during time trials and enhanced fatigue tolerance. These findings suggest that L-Citrulline's greatest benefits are more pronounced among untrained individuals rather than among highly trained athletes, indicating a potential population-specific advantage.
How it works
L-Citrulline supplementation increases arginine levels in the blood, subsequently enhancing nitric oxide production. Nitric oxide plays a crucial role in vascular health due to its vasodilatory effects, facilitating increased blood flow to active muscle tissues during exercise. The supplementation primarily targets the nitric oxide synthase enzyme, which converts arginine into both citrulline and nitric oxide. This action contributes to improved cardiovascular function and muscular performance during physical activities.
Side effects
L-Citrulline is generally regarded as safe when consumed at recommended doses. Common side effects have not been widely reported, but some individuals may experience gastrointestinal discomfort, including stomach cramps or diarrhea. Instances of adverse reactions are rare (<1%). Caution is advised for individuals with severe kidney or liver dysfunctions. Additionally, L-Citrulline may interact with medications that affect blood pressure. Pregnant or breastfeeding women are encouraged to seek medical advice due to limited safety research in these populations.
Dosage
The effective dosage range for L-Citrulline is approximately 2.4-6 g/day, with chronic supplementation over 7-16 days considered optimal for significant benefits. Acute doses have shown limited effectiveness on performance metrics, making chronic use preferable for sustained effects. No maximum established safe daily dose exists, but doses up to 12 g/day have been utilized in studies without notable adverse reactions. Citrulline malate, a mixture of citrulline and malic acid, is commonly used; however, evidence supporting its superiority over pure L-Citrulline remains inconclusive.
FAQs
Is L-Citrulline safe?
Yes, L-Citrulline is generally considered safe for healthy individuals, though those with underlying health issues should consult a healthcare professional.
How should I take L-Citrulline?
Chronic supplementation is recommended for optimal benefits, ideally at doses of 3.4-6 g/day over several days rather than acute doses before workouts.
What results can I expect?
You may experience improved endurance performance and muscle oxygenation, especially if you are untrained or at a low competitive level.
Can I just take L-Citrulline before workouts?
Acute supplementation generally does not significantly enhance performance; chronic supplementation is shown to be more effective.
