L-Citrulline
L‑Citrulline
Snapshot
L‑Citrulline is a nonessential amino acid that enhances nitric oxide production, supporting blood flow, exercise performance, and muscle recovery.
What is L‑Citrulline?
L‑Citrulline is an amino acid produced in the body from ornithine via the urea cycle. Supplementation raises plasma arginine levels more effectively than arginine itself, thereby boosting nitric oxide synthesis.
Where It Comes From
Dietary citrulline comes from watermelon, cucumbers, and other melons. In supplements, L‑citrulline is provided as free‑form powder or combined with malate (citrulline malate) to support energy metabolism.
Key Nutrients & Compounds
Supplemental L‑citrulline delivers the pure L‑isomer. Citrulline malate combines citrulline with malic acid, enhancing the Krebs cycle and energy production, in addition to nitric oxide support.
Health Benefits
L‑Citrulline promotes vasodilation and improved circulation by increasing arginine and nitric oxide levels. It enhances exercise endurance, reduces muscle soreness, and supports recovery by clearing ammonia and lactic acid.
Recommended Dosage
Typical doses range from 3 to 6 grams of L‑citrulline or 6 to 8 grams of citrulline malate per day, taken 30–60 minutes before exercise.
How to Use It
Mix powder into water or sports beverages and consume prior to workouts. Citrulline malate is often used in pre‑workout formulas; free‑form citrulline can be used in intra‑workout drinks.
Who Should Use It?
Ideal for athletes and active individuals seeking to improve blood flow, endurance, and post‑exercise recovery. It benefits those experiencing muscle fatigue or seeking enhanced pump and performance.
Possible Interactions or Cautions
L‑Citrulline is well tolerated; high doses may cause mild gastrointestinal discomfort. It may lower blood pressure—those on antihypertensive medications should monitor levels. Consult a healthcare provider if pregnant or nursing.
Final Thoughts
L‑Citrulline effectively boosts nitric oxide and energy metabolism, making it a valuable supplement for performance, recovery, and cardiovascular support. When dosed appropriately around exercise, it delivers noticeable benefits.
Scientific Studies
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Pérez‑Guisado, J., & Jakeman, P. M. (2010). Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. Journal of Strength and Conditioning Research, 24(5), 1215–1222.
https://doi.org/10.1519/JSC.0b013e3181e09f4b -
Bailey, S. J., et al. (2015). Dietary nitrate supplementation enhances blood flow and oxygen delivery to skeletal muscle during exercise in hypoxia. Journal of Applied Physiology, 119(4), 385–395.
https://doi.org/10.1152/japplphysiol.00049.2015 -
Hickner, R. C., et al. (2006). L‑citrulline reduces time to exhaustion and insulin response to a graded exercise test. Medicine & Science in Sports & Exercise, 38(4), 660–666.
https://doi.org/10.1249/01.mss.0000205180.47390.52