Give two reasons why clinical trials have to be done before drugs are made freely available?

There are many reasons why clinical trials need to be conducted before making new drugs commercially available. First of all, drug makers need to be sure that a drug is safe, this is tested by giving the drug to a group of volunteers in a controlled environment (staying at a clinic for several days) and monitoring their vital signs, their blood chemistry, and checking for any side effects. Secondly, clinical trials are needed to determine whether a drug is effective at treating a certain condition. Drugs in clinical trials are given blind, meaning that the doctor nor the patient knows whether someone is taking the drug being studied or a placebo (sugar pill). Studying the effects of the drug in this scenario can prove whether the drug is effective. Finally, clinical trials are also used to determine the proper dose of a drug by giving escalating doses to volunteers and monitoring the blood levels of the drug and watching for any side effects.