Mega-Sel is a unique Selenium and Vitamin Ecompound, vital to the health and performance of your horse. Its patented, liquid formula provides Selenium and Vitamin E in a palatable form which is readily consumed and utilized by the horse. Powdered supplements are safe, but they may settle out of the grain, not to be consumed at all. Injectables, although effective, have potentially dangerous side effects anaphylactoid reactions. Mega-Sel offers you both safety and effectiveness