Byetta is a drug marketed for the treatment of Type 2 diabetes. While some diabetes drugs come in pill form, Byetta is a pre-filled pen which the patient injects one hour prior to the morning and evening meal. Unlike some other diabetic drugs, Byetta (exenatide) is made from a synthetic form of a hormone—exendin 4—which naturally occurs in the saliva of the Southwestern Gila monster and was discovered in 1992. The synthesized version of the hormone is nearly 50% identical to another hormone which occurs naturally in the human digestive tract—GLP-1. This GLP-1 hormone increases the insulin in the body, enabling it to balance excessively high levels of blood sugar. The body of a diabetic may lose the ability to produce the necessary levels of GLP-1, allowing blood sugar levels to rise to potentially dangerous levels.