The use of animals in drug development dates back to the period when humans started to look for ways to prevent and cure ailments. The dilemma to continue animal experiments in education and research continues with varied and confusing guidelines. Over the last century, every Nobel Prize for medical research has been dependent on animal research. It is estimated that 50–100 million animals are experimented worldwide from zebrafish to nonhuman primates every year. Most animals are used in only one procedure, after which they either die or are euthanized. The main concern for animals in experimentation is physical and mental stress and pain. Various alternatives to animal use are—in vitro techniques, in silico (computer based/dry lab tests), and invertebrate animals can be used to replace the more commonly used laboratory animals.