Let’s begin with the disagreeable side of this controversial topic. First is animals are not suitable for experiment. It is mainly because the differences between animals and humans can blind the researchers from discovering effective cures and treatments. Many chemical are only harmful to animals, but not to humans. According to a report on Slate.com, "source of human suffering may be the dozens of promising drugs that get shelved when they cause problems in animals that may not be relevant for humans." For example, Aspirin−once almost be banned because of animal-testing. It is dangerous for some animals, but actually, it can be beneficially used in humans. It can be used to lower the risk of organ transplant rejection. Likewise, animals and humans have different reproductive cycles and life spans, so it will be very difficult to analyze the information when the researchers do the experiment in those fields. The evidences supportively are why animals are not appropriate for being used in experiments.