The beginning of animal testing can be dated back to ancient Greek and Roman times. Early Greek physician-scientists, such as Aristotle (384-322 BC) and Erasistratus (304-250 BC), performed experiments on living animals. These famous physicians examined tendons and nerves in animals’ bodies to understand their operating differences. Likewise, Greek physician Hippocrates dissected animals which allowed him to compare it to the human body. Medical advancements such as the development of X-rays, organ transplants, and blood transfusions would have been difficult to achieve without animal experimentation. Over the years, scientists have repeatedly used animals in research with the pure interest to advance the understanding of different scientific fields and improve the quality of humans’ lives. What is animal testing? Animal testing is the use of animals in experiments to further develop science. Also called animal experimentation, animal research, and in vivo testing, animal testing is used to assess the safety and effectiveness of products and medications and advances pure and applied research (McClellan). It is used to test new treatments for humans diseases, and improve surgical techniques and medicines. Most animals in research are specifically bred for experimentation in laboratories. Although this treatment of animals may be deemed unethical and cruel, the data that has been extracted from experiments cannot be disagreed to be beneficial to humans. Using animals for testing is a very heavily debated subject in which different sides and perspectives are argued upon. Those who oppose animal research will say it is a cruel, nonhuman scientific experimentation carried out on innocent animals. However, those for it will agree that the use for animals is crucial for the advancement of medicine and biological knowledge. There is also a third argument to this subject: some may agree that animal testing is a monstrous act, but also believe it is necessary and beneficial for humans. In a huge victory for animals and those who oppose this practice, the numbers of animals tested on dropped almost fifty percent in 1966 to 1998. In fact many alternatives have been found to reduce the animal testing. For example, some countries like Israel, India, and the European Union have banned any cosmetic products that have been tested on animals (PETA). This means that big marketing organizations will be forced to stop the practice of using animals as a way to test their products. Microdosing has also had a huge impact in the decreasing number of animals being used. Microdosing is an experiment in which humans are given a very small portion of a drug to test the effects on the body without actually damaging the whole body system (Mone 21). Other alternatives include 3D-printing, computer models and simulations, and genetic testing methods. More research has been done in this area in order to eliminate animal testing completely.One of the biggest industries where animal testing is needed is cosmetics. These beauty products are required to be tested on animals first in order to sell them to humans. Tests for cosmetics require many animals to be experimented on. For example, skin sensitizations tests for allergic reactions on the skin. This test utilizes an estimated amount of 32 guinea pigs and 16 mice. Likewise, skin and eye corrosion/irritation tests use around one to three rabbits. An example of an experiment is the acute oral toxicity test. This test regulates the quantity of a substance that results in half of the exposed creatures to perish within fourteen days of exposure when the substance is swallowed. Scientists use a feeding tube to force the test substance down a rat’s throat. As a result, rats may undergo diarrhea, bleeding from the mouth, seizures, paralysis, and/or even death. Regulations on animal testing have been passed in most countries. Some countries like the United Kingdom have laws such as the Animals (Scientific Procedures) Act of 1986 which regulates the use of protected animals, and states that animals bred and used for scientific procedures should be well-taken care of. In the United States, however, there is only one federal law that covers animals in research. Enacted in 1966, the Animal Welfare Act (AWA) provides only minimal protection for certain animals, excluding rats, rabbits, mice, and birds — who together compose an estimate of 90-95% of all animals in labs (“Laws and Regulations”). In fact, stricter controls from the 1980’s on animal research were based on the three R’s: reduction, refinement, and replacement (Balls 196). Animal research has played a vital role in the breakthrough of medicine over the decades. Because animals and humans share similar characteristics, scientists have relied on them to test different products such as vaccines, medicines, and cures. In 1937, a company in the United States created a preparation containing DEG (diethylene glycol). With no background knowledge of this being poisonous to humans, the chief pharmacist and chemist of this company added raspberry flavoring to the drug and marketed the product. The preparation led to poisoning, killing hundreds of people. No animal testing was done on this product (Hajar). This is why animals are needed for medical procedures and safety. Due to researching on animals diseases and viruses rates have dropped. For example, cancer survival rates have increased and smallpox has been completely obliterated (Breen 38). Another example of animal research used in medicine is a study performed in 2013 by undergraduates. They took male rats and performed castration surgery on them to “demonstrate the physiological effects of testosterone” (Belanger 27). As a result of the lab, students learned hands-on skills, histological techniques, data collection, and analysis. Without in vivo testing these breakthroughs could not have been possible in today.Animal testing is a practice that has been used for thousands of years. This practice has greatly contributed to our lives and will continue to do so until more methods that do not involve animals are found. Animal testing has assisted humans learn more about illnesses that affects both humans and animals, and come up with vaccines and treatments to help prevent them. Animal testing has been a big contribution in daily products that we use. People who oppose these experiments on animals are hoping for the day when animals are no longer needed, but until then animal testing will continue to be vital for humans.