L-Citrulline: Evidence-Based Benefits, Mechanisms, and Uses
What is L-Citrulline?
L-Citrulline is a non-essential amino acid found in foods like watermelon and produced naturally in the body. It plays a key role in the urea cycle by helping remove ammonia, but it's best known for its role in nitric oxide (NO) production.
Unlike L-arginine, which is rapidly broken down in the gut and liver, L-citrulline is well absorbed and converted to arginine in the kidneys, leading to more sustained increases in blood arginine levels.
Benefits of L-Citrulline
𖤓Improved Blood Flow
By boosting nitric oxide production, L-citrulline can help relax and dilate blood vessels (vasodilation). This may benefit cardiovascular health and exercise performance.
𖤓Exercise Performance
Clinical studies suggest L-citrulline supplementation can reduce muscle fatigue and improve endurance by enhancing blood flow and reducing perceived exertion.
𖤓Erectile Function Support
Because of its nitric oxide effects, some small studies have explored L-citrulline as a natural aid for erectile dysfunction, with early evidence showing it may modestly improve hardness scores in men with mild ED.
𖤓Ammonia Clearance
Athletes sometimes use L-citrulline to help clear ammonia produced during intense exercise, potentially reducing fatigue.
Evidence Summary
Bailey et al. (2015): Found improved cycling time-trial performance with citrulline malate supplementation.
Cormio et al. (2011): Observed improved erection hardness in men with mild ED after L-citrulline supplementation.
Sureda et al. (2010): Reported reduced perceived exertion and ammonia concentration in athletes.
While these results are promising, larger, well-controlled trials are needed to confirm many of these benefits, especially for clinical applications.
Dosage and Forms
Typical dosages range from 3–6 grams/day of pure L-citrulline or 6–8 grams/day of citrulline malate.
Often taken 30–60 minutes before activity for performance effects.
Generally well tolerated, with minimal reported side effects in research at standard doses.
Safety Considerations
L-Citrulline appears safe for most healthy adults at recommended doses. As with any supplement, individuals with underlying medical conditions that could lead to an adverse reaction should consult with their healthcare provider before starting supplementation.
Bottom Line
L-Citrulline is a well-researched amino acid supplement with potential benefits for exercise performance, blood flow, and even mild erectile dysfunction support. Its superior bioavailability compared to arginine makes it a popular choice for athletes and those looking to naturally support nitric oxide production.
𖤓 Ready to Try L-Citrulline?𖤓
If you’re looking for a high-quality, lab-tested L-Citrulline supplement, I’ve partnered with Bulk Supplements to offer products I trust in my practice! Check it out by clicking here!
