Stimulin, a proprietary dietary supplement, is based on the amino acid L-citrulline. Dr. Wong himself has long used the formula as a substitute for L-arginine.

“1 started taking two tablets twice a day,” says Dr. Wong. “The dosage was much SUPPORT FOR SEXUAL VITALITY’ lower than what I had been using with L-arginine, and there was no fishy smell. Even still, two days later, the effects were obvious. There was increased penile tumescence.” He jokingly notes he had to “put on warm-ups instead of tight-fitting jeans.”

L-citrulline maybe more potent than l-arginine because the body’s production of nitric oxide can be impaired, due to interference by other chemicals—but Stimulin with citrulline overcomes impaired nitric oxide synthesis even better than L-arginine.

At Johns Hopkins Asthma and Allergy Center, Baltimore, Maryland, relaxation of living tissue was inhibited markedly by the compound L-nitro-n-arginine. This same compound inhibits the body’s production of nitric oxide. Such inhibition was reversed by either L-argiriine or L-citrulline. Howevei according to Drs. J.L. Ellis and N. Conanan, L-citrulline was more potent and effective. L-citrulline was also better than arginine at reversing inhibition produced by another nitric oxide synthase inhibitor, L-nitro monomethyl arginine.

The body requires L-citrulline to maintain optimal levels of arginine. In a study conducted by researchers associated with the U.S. Department of Agriculture, Tufts University, Boston, rats were fed arginine-deficient diets containing ornithine or citrulline. The addition of citrulline (but not ornithine) to the diet restored blood arginine concentrations.