Supplement Forms/Alternate Names:

  • L-citrulline
  • Citrulline malate


Citrulline is an amino acid found in the body. It has been used to improve blood pressure and athletic performance. Citrulline can be taken as a pill or powder.


5 grams 1 to 3 times daily

What Research Shows

Likely Effective

Not Enough Data to Assess

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe to take citrulline in small doses for a short time. Not enough studies have been done to say whether it is safe to use for a long period. It is also not known whether it is safe to take by women who are pregnant or breastfeeding.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.


REFA Athletic Performance

REFA1 Trexler ET, Persky AM, et al. Acute Effects of Citrulline Supplementation on High-Intensity Strength and Power Performance: A Systematic Review and Meta-Analysis. Sports Med. 2019;49(5):707-718.

REFB Erectile Dysfunction

REFB1 Cormio L, De Siati M, et al. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction. Urology. 2011 Jan;77(1):119-122.

REFC Heart Failure

REFC1 Orozco-Gutiérrez JJ, Castillo-Martínez L, et al. Effect of L-arginine or L-citrulline oral supplementation on blood pressure and right ventricular function in heart failure patients with preserved ejection fraction. Cardiol J. 2010;17(6):612-618.

REFC2 Balderas-Munoz K, Castillo-Martínez L, et al. Improvement of ventricular function in systolic heart failure patients with oral L-citrulline supplementation. Cardiol J. 2012;19(6):612-617.

REFD High Blood Pressure

REFD1 Mahboobi S, Tsang C, et al. Effect of L-citrulline supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials. J Hum Hypertens. 2019;33(1):10-21.

REFD2 Barkhidarian B, Khorshidi M, et al. Effects of L-citrulline supplementation on blood pressure: A systematic review and meta-analysis. Aviencanna J Phytomed. 2019;9(1):10-20.

REFE Obesity

REFE1 Figueroa A, Alvarez-Alvarado S, et al. l-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men. Br J Nutr. 2016 Jul;116(2):279-285.

Revision Information

  • Reviewer: EBSCO NAT Review Board Eric Hurwitz, DC
  • Review Date: 02/2020
  • Update Date: 06/17/2020