Changes are occurring within Brazilian institutes of higher education; currently several universities are reviewing their course offerings and teaching approaches to determine if they meet the needs of today's undergraduate students. When changes are made to the curriculum of experimental courses, there should be an understood guarantee that all efforts to avoid ethical and biosafety issues have been diligently considered. Ethical considerations lead us to create an alternative experimental session to be conducted that eliminated the use of rats, the conventional "in vivo" model employed for learning metabolism of glycogen in our university. To avoid possible biosafety issues, we prepared an alternative sample to simulate human urine, which we called guarurine. Using our new method, it is possible to verify positive results imitating a diabetic and starving people samples for detection of glucose and ketone. The alternative tool described herein is not only particularly suited to bypass the ethics of using animals for teaching, but also permits the discussion of significant aspects of pathological and physiological situations such as diabetics and starvation in a simple, safe, and interesting way.