There are thousands of chemicals, both manmade and naturally occurring, to which humans are exposed. It is now common knowledge that a drug's potency is only one factor in determining its success. Absorption, distribution, metabolism, excretion, and toxicity are only some of the features that need to be taken into account. Due to the extensive resources needed to evaluate a chemical, little is learned about its potential toxicity. There are a wide range of toxicities or adverse medication effects that need to be assessed during both the preclinical as well as clinical trial phases to ensure patient safety. To determine the safety of certain chemicals, scientists have typically used in in vitro as well as in vivo trials. Yet, not only are such research costly and time-consuming, but animal testing experiments specifically are increasingly being criticized for being unethical.