This was recommended to me by my ENT Dr., the same Dr. that diagnosed my EBV/FM. Dr. Paul Toffel, La Canada California He gives me a 2mg shot every 3 weeks. It boosts the immune system a million times better than B-12 shots. They give them to the military soldiers before shipping them off to war...helps fight illness and keep them strong. I've been getting these for one year and noticed a dramatic difference in my overall energy and ability to function.