Objectives
To test the efficacy and safety of oral L-citrulline supplementation in improving
erection hardness in patients with mild erectile dysfunction (ED). L-arginine supplementation
improves nitric oxide-mediated vasodilation and endothelial function; however, oral
administration has been hampered by extensive presystemic metabolism. In contrast,
L-citrulline escapes presystemic metabolism and is converted to L-arginine, thus setting
the rationale for oral L-citrulline supplementation as a donor for the L-arginine/nitric
oxide pathway of penile erection.
Methods
In the present single-blind study, men with mild ED (erection hardness score of 3)
received a placebo for 1 month and L-citrulline, 1.5 g/d, for another month. The erection
hardness score, number of intercourses per month, treatment satisfaction, and adverse
events were recorded.
Results
A total of 24 patients, mean age 56.5 ± 9.8 years, were entered and concluded the
study without adverse events. The improvement in the erection hardness score from
3 (mild ED) to 4 (normal erectile function) occurred in 2 (8.3%) of the 24 men when
taking placebo and 12 (50%) of the 24 men when taking L-citrulline (P < .01). The mean number of intercourses per month increased from 1.37 ± 0.93 at baseline
to 1.53 ± 1.00 at the end of the placebo phase (P = .57) and 2.3 ± 1.37 at the end of the treatment phase (P < .01). All patients reporting an erection hardness score improvement from 3 to 4
reported being very satisfied.
Conclusions
Although less effective than phosphodiesterase type-5 enzyme inhibitors, at least
in the short term, L-citrulline supplementation has been proved to be safe and psychologically
well accepted by patients. Its role as an alternative treatment for mild to moderate
ED, particularly in patients with a psychologically fear of phosphodiesterase type-5
enzyme inhibitors, deserves further research.
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Article info
Publication history
Accepted:
August 21,
2010
Received:
July 13,
2010
Identification
Copyright
© 2011 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
