“The idea that human life is sacred precisely because it is human life is medieval,” writes Peter Singer in his book Animal Liberation. Animals are everywhere, whether at home as companions, at the circus as entertainment, or in our closets as clothing. US citizens are aware that the medications we take must be approved by the Food and Drug Administration (FDA), but many of us are unaware of how exactly most of these medications are approved and who the test dummies are used to concoct these drugs. Conducting medical research with animals has caused legal, scientific and ethical dilemmas regarding this topic. In this article I will try to provide an unbiased understanding of the research experiments that animals have to undergo and the ethical questions that arise, supported by Peter Singer. Doctor-scientists such as Aristotle and Erasistratus have been recorded as having performed experiments on live animals. In 1937, a pharmaceutical company here in the United States, invented a drug called Elixir Sulfanilamide. This drug consisted of a highly poisonous solvent that led to the deaths of hundreds of people. It was only then that the Federal Food Drug and Cosmetic Act required testing of drugs on animals before they could be marketed to humans. In 1959, WMS Russell and R.L. Burch introduced the three R's for the use of humane treatment of animals. The first R is for replacing animals with non-living models, the second R is for reducing animal use, and the third R is for perfecting animal use practices. The Animal Welfare Act, signed into law in 1966, is the only federal law that regulates the treatment of a… paper medium… food stream. However the question about pain still arises: do animals really feel pain or is it just a hypothesis. Pain is known to be a “mental event” that only we feel and the only way people know we feel pain is because we tell them. Animals, on the other hand, have their own way of communicating that they would like to be helped; Behavioral signs of pain include writhing, frowning, moaning, appearing fearful, and yelping. Lord Brain, the neurologist, once said: "At least I cannot doubt that the interests and activities of animals are related to awareness and feelings in the same way as my own, and that they may be just as vivid." This explains that animals and humans have a correlation with each other when it comes to their surroundings and activities. Therefore animals would be aware when they are in a tense environment and yet feel pain.