Plazma™, Mag-10®, and Surge® Workout Fuel are the only supplements I know of that contain extremely high quaantities of citrulline malate (CM). Although human data are somewhat limited, CM appears to protect muscles from fatiguing and help them recover faster from intense exercise. Colleagues of mine from Italy give their athletes high doses of CM (up to 12 grams, all at once) prior to training and report amazing results.
A preliminary report from Spanish researchers noted a 52% increase in weight training performance (bench press repetitions to failure at 80% of maximum) from an 8-gram dose of CM taken 60 minutes prior to exercise. CM also reduced subjects' muscle soreness by 40%.
How it works isn't exactly known, but one hypothesis is that CM helps buffer lactate and ammonia build up in skeletal muscle. These data are very intriguing, and I'm hopeful that several of my colleagues will follow up with high-quality clinical trials here in the U.S.
Joaquin Perez-Guisado, MD, PhD
Department of Medicine, University of Cordoba, Cordoba, Spain