Because of the Standard American Diet, many people have become deficient in the amino acid lysine, and too high in the amino acid arginine. Chocolate, whole wheat and white flour, peanuts, and soy are common ingredients or additives in food and contain far more arginine than lysine. However, more lysine than arginine is desperately needed by the body in order to fight viruses! The amounts of Arginine available to the virus dictates it’s ability to function. Due to many factors (including toxicity and lowered immune systems), viruses such as Epstein Barr Virus and shingles have been able to come into our systems and lie dormant, causing low-grade symptoms such as fatigue. I usually take one l-lysine capsule daily to keep up my body’s defense against EBV. I don’t get sick, but if I did, I would up my dosage to 2-3 capsules when I felt something coming on.