The US Food and Drug Administration (FDA) has recalled homeopathic remedies made by a company called Terra-Medica because they may contain actual medicine—possibly penicillin or derivatives of the antibiotic.

Terra-Medica creates a range of homeopathic capsules, suppositories and ointments under clinical-sounding brand names including Pleo-Fort, Pleo-Quent and Pleo-EX. The FDA has found that 56 lots of the drugs may contain penicillin or derivatives of penicillin, which may have been produced during fermentation. This is a problem, because Terra-Medica says that its products don't contain antibiotics. The Pleo Sanum range of products, for example, "can address acute and chronic inflammations and infections without the use of traditional antibiotics." Homeopathic remedies are generally highly diluted substances (in fact, the more a substance is diluted, the more effective homeopaths deem it to be) that practitioners claim can cause the body to heal itself. A 2010 House of Commons Science and Technology Committee report found these remedies to perform no better than placebos.

Homeopathic medicines are regulated by the FDA in the same way that over-the-counter, nonprescription drugs are in terms of purity and packaging, but they aren't subjected to the same level of testing of effectiveness before they can be sold.

Terra-Medica is voluntarily recalling the batches after the FDA determined that the products may contain these antibiotics. "In patients who are allergic to beta-lactam antibiotics, even at low levels, exposure to penicillin can result in a range of allergic reactions from mild rashes to severe and life-threatening anaphylactic reactions."

Michael Marshall, the vice president of Merseyside Skeptics, the group behind anti-homeopathy campaign group 10.23, said that it's "[funny] to see homeopathic products recalled because, for a change, they actually contain some real ingredients." But, he added, there's "real cause for concern here."

"People are often persuaded to try homeopathy by claims that homeopathic remedies have no side effects—and that's true, albeit because they also have no beneficial effects. These so-called medicines are simply drops of water, put onto sugar pills, and no more than that," Marshall said.

This is not the first time that the FDA has had to recall homeopathic remedies. In 2009, it recalled the Zicam Cold Remedy products because they were causing people to lose their sense of smell—some 130 people reported long-lasting loss of their sense of smell to the FDA, while 800 more people complained to Zicam. Zicam's parent company Matrixx ended up recalling all of the products—the problem seemed to be caused by taking zinc intranasally.

The FDA also explored products from Nelson's, one of the biggest homeopathy suppliers in the UK, which makes products for retailers like Boots.

"Their inspection found some incredibly worrying things," says Marshall. This included the fact that one out of every six bottles in one observed batch did not receive the dose of active homeopathic drug solution "due to the wobbling and vibration of the bottle assembly during filling of the active ingredient," the report—written by the FDA's Steven Lynn—explains.

"The active ingredient was instead seen dripping down the outside of the vial assembly. Your firm lacked controls to ensure that the active ingredient is delivered to every bottle," said the 2012 assessment.

Glass fragments were also observed in an assembly line area where open glass vials were inserted into outer plastic sheaths. "Your firm failed to implement adequate measures to prevent glass contamination and had no documentation to demonstrate that appropriate line clearance and cleaning is conducted following occurrences of glass breakage, which has been a recurring problem."

Marshall says that cases in which trusting vulnerable consumers have believed the claims of homeopaths and "forgone real medicine" in place of "these overpriced sugar pills" are "too numerable to count" and "often with unnecessary and tragic consequences."

"Our advice to the consumer is clear: leave sugar pills in the 19th century where they belong."

This story originally appeared on Wired UK.