Citrulline Health Benefits
Citrulline health benefits include an ability to help manage erectile dysfunction, high blood pressure, fatigue, and other conditions including increasing libido in men. The body produces citrulline (L-citrulline), which is an amino acid also found in some foods, such as watermelon, cucumbers, and cantaloupe.
The body transforms L-citrulline into another amino acid, L-arginine, and also to nitric oxide. Citrulline is believed to work by increasing the supply of nitric oxide and substances the body needs to produce certain proteins. Citrulline may also help dilate veins and arteries to improve blood circulation and reduce blood pressure. Therefore citrulline health benefits may be appreciated by people who suffer with a variety of conditions associated with blood flow.
Citrulline and Erectile Dysfunction
Arginine is known to help with erectile dysfunction. However, oral arginine supplements are greatly metabolized by the body. L-citrulline converts to arginine in the body and does not break down and lose potency. Therefore, a team of researchers in Italy set out to test the efficacy and safety of citrulline supplements in improving erection hardness in men who had mild erectile dysfunction.
In the single-blind study, 24 men (mean age 56.5 years) received placebo for one month and then citrulline (1.5 g/day) for one month. Two (8.3%) of the 24 men reported an improvement in erection hardness score from 3 (mild erectile dysfunction) to 4 (normal erectile function) when taking placebo. However, 12 (50%) of 24 men reported similar results when taking citrulline. No adverse effects were noted. All the men who reported an improvement in erectile function said they were very satisfied with the results. The study’s authors concluded that at least in the short term, citrulline supplementation is safe and well accepted by patients. (Cormio 2011)
Other Citrulline Health Benefits
A Japanese study investigated the effect of citrulline supplementation on arterial stiffness in middle-aged men. The double-blind, randomized, placebo-controlled trial consisted of 15 healthy men who were given 5.6 g/day of citrulline (8 men) or placebo for seven days. After seven days, indicators of arterial stiffness were significantly improved in the men who took citrulline. No significant differences in blood pressure were noted between the two groups. The findings suggest that short-term use of citrulline health benefits from supplementation may include improvement in arterial stiffness, independent of blood pressure. (Ochiai 2010)
In a more recent study, researchers explored the effect of a watermelon supplement (2.7 g citrulline/1.3 g arginine) or placebo on heart rate and various other heart health measures in four men and five women (mean age, 54 years) who had prehypertension (average, 134/77 mm Hg). The treatment involved taking either the supplement or placebo daily for six weeks followed by a four-week washout period and then crossover.
Compared with placebo and baseline measures, there was a significant effect associated with the watermelon supplement on brachial pulse pressure, aortic systolic blood pressure, aortic PP, and augmentation index. The authors concluded that “watermelon supplementation improves aortic hemodynamics through a decrease in the amplitude of the reflected wave in individuals with prehypertension.” (Figueroa 2011)
How To Take Citrulline
Before exploring citrulline health benefits, consult a knowledgeable healthcare practitioner regarding the appropriate dose. No side effects have been reported from the use of citrulline.
Cormio L et al. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction. Urology 2011 Jan; 77(1): 119-22
Figueroa A et al. Effects of watermelon supplementation on aortic blood pressure and wave reflection in individuals with prehypertension: a pilot study. Am J Hypertens 2011 Jan; 24(1): 40-44
Ochiai M et al. Short-term effects of l-citrulline supplementation on arterial stiffness in middle-aged men. Int J Cardiol 2010 Nov 8