The FDA is taking aim at homeopathic remedies — pills and preparations sold over-the-counter that claim to cure diseases with tiny doses of stuff that makes people sick.

Homeopathy, which debuted in Germany more than 200 years ago, is now a $6.4 billion business nationwide, and growing. After decades of ignoring these products, U.S. drug regulators are finally asking hard questions about what has long been derided by mainstream doctors and scientists as quack medicine.

“Consumers are constantly being misled about homeopathics,” Edzard Ernst, an emeritus professor of complementary medicine at the University of Exeter in the United Kingdom, told BuzzFeed News. “They believe that they are natural, safe, and effective — none of this is true.”

That’s not just Ernst’s view. Doctors since Oliver Wendell Holmes Sr. in 1842 have mocked homeopathy. This past June, an Australian government review found “no health conditions for which there is reliable evidence that homeopathy is effective.” And in August, the U.S. CDC noted that “there is little evidence to support homeopathy as an effective treatment for any specific condition.”

Homeopathic products can also pose rare safety risks, according to the FDA. In 2009, for example, the agency received more than 130 accounts of people who lost their sense of smell after taking Zicam homeopathic cold remedies. One expert testified to the FDA that those accounts raised concerns about toxic levels of zinc.

In 2010, teething tablets marketed as being “100% natural” and having “no side effects” were linked to “reports of serious adverse events in children” such as seizures, slowed breathing, and muscle weakness, according to the FDA, sparking a recall.

Homeopathic drugs are not subject to much regulatory scrutiny. The FDA ensures that their manufacturing facilities are clean, but the products are not evaluated for their health claims. (This is even less regulation than what’s required for dietary supplements, vitamins, herbs, and minerals, which face some limits on the health claims they can make.)

But that may change. This month, both the FDA, which oversees drug safety, and the Federal Trade Commission (FTC), which oversees drug ads, will end lengthy public comment periods that followed hearings on homeopathy. The FTC smacked its sister drug-safety agency in public comments in August, calling for the FDA to crack down on homeopathic products, which “may harm consumers.”

Homeopathy advocates say they support labels for their products that would tell consumers the remedies haven’t been tested by the FDA (and perhaps remove their customary litter of inscrutable Latinisms such as “Oscillococcinum,” a supposed flu cure, that read like Harry Potter spells). Still, homeopathy's supporters say these remedies have a much better safety record than conventional drugs, along with millions of satisfied customers.

“We believe they are proven to be effective and extremely safe,” Ronald Whitmont, an internist at the New York Medical College and president of the American Institute of Homeopathy, told BuzzFeed News. The institute has been around since 1844 (longer than the American Medical Association), publishes its own research journal, and has certified dozens of physicians as “homeotherapeutics” specialists.

Noting the warnings about some homeopathic remedies issued in recent years by the FDA, Whitmont said, “we see the [federal agencies’] inquiry as a legitimate exercise into what over-the-counter homeopathic products should be supported.”