Food and Drug Administration
The US Food and Drug Administration (FDA) regulates food safety, tobacco, dietary supplements, legal medications, vaccines, biopharmaceuticals, blood transfusions, medical devices, electromagnetic radiation-emitting devices (ERED), veterinary products, and cosmetics.
In theory, the FDA's job is to make sure stuff like this will not harm you or rip you off.
In practice, the FDA has done less than a sterling effort in doing that job, especially in recent years.
Then there are all the recalls after FDA approval: Baycol (2001), Vioxx (2004), Bextra (2005), NeutroSpec (2005), Cylert (2005), Palladone (2005), and Permax (2007).
Finally, there is "CPG Sec. 400.400 Conditions Under Which Homeopathic Drugs May be Marketed" which "The Federal Food, Drug, and Cosmetic Act (the Act) recognizes as official the drugs and standards in the Homeopathic Pharmacopeia of the United States and its supplements (Sections 201 (g)(1) and 501 (b), respectively).", which turns any possible overseeing of the FDA over the homeopathic "drug" market in terms of safe and effective into a bad joke.
As a result, the FDA has four main enemies: consumer advocates who claim that the FDA since 1980 has become too buddy buddy (especially with the 1992 Prescription Drug User Fees Act) with the drug and chemical companies and is not doing its freaking job, alternative medicine, which considers this "science" stuff unconscionable oppression, libertarians, who want to be free to buy and sell any delusional shite imaginable, as the free and sovereign individuals they want to be (just don't die at the hospital which we just privatized!), and the conservatives who consider all these regulations an impediment to business making a profit.
Libertarian think tank the Independent Institute conducted a study which suggested that many more people die from the lack of drugs that the FDA is slow in approving than would die of the drugs that would be approved in a less rigid approval process due to the FDA potentially suffering greater political penalties from approving bad drugs than from disapproving good ones.
Due to legal loopholes, some non-functional medications can be sold as long as they include the disclaimer "this statement has not been evaluated by the FDA".