When it comes to modern medicine and any new drug on the market, medical research companies invest in drug trials where they take a new product on one side and test a placebo drug on the other to see which if the drug is more efficient than the placebo effect.
By doing drug trials, medical research companies conclude the efficiency of a drug and whether or not it is fit for use for the general public. Without testing new medicine, there may be unforeseen problems and it will be like playing with the lives of patients.
By conducting these drug trials, companies can actually save a lot of money too; instead of dashing out a untested product (Which almost never happens) companies can test a product on patients and determine whether or not it will be profitable over other types of the same medicine already available and at what pricing scheme.
Because drug trials are mandatory, no new medicine will ever see the light of day without testing first, as it is not only in the best interest of the public to receive proper drugs, but also in the interest of companies to help avoid possible lawsuits and generally loss in revenue.