The Food and Drug Administration is warning the public to stay far away from supplements, touted as a cancer cure, that are made with an ingredient linked to irregular heartbeats, seizures, and even deaths.
On Wednesday, the agency issued a public health alert for dietary supplements containing cesium salts, a kind of mineral salt. These products usually contain a specific formulation known as cesium chloride. The alert warns both customers to not take these products and doctors not to recommend them.
“Multiple clinical case reports and non-clinical studies show significant safety concerns related to the use of such products, including potentially fatal cardiac arrhythmias, hypokalemia (low potassium), seizures, syncope (fainting, unresponsiveness), and death,” the alert reads.
The radioactive version of cesium is routinely used in medicine as part of radiation therapy for certain cancers. But for decades, naturopaths and others in the alternative medicine world have promoted the non-radioactive version of these salts as a cancer treatment. Their theory is that many tumors thrive in a low-pH, acidic environment, so cesium is supposed to act as an alkalinizing agent that counteracts this acidity in the body and suppresses the cancer.
In truth, there’s no evidence that cesium salts can treat cancer or anything else. But as the FDA notes in its alert, there have been reports of people with cancer dying after having taken them. One case study published in 2014 documented a 61-year-old woman whose heart stopped after she injected a dose of cesium chloride into a mass on her right breast that she suspected was cancerous. Though the woman was resuscitated and doctors confirmed her breast cancer, she never regained consciousness and died a little over a week later at home.
Dangerous as cesium salts might be, you won’t stumble onto them at your local pharmacy.
“While it appears that few dietary supplements containing cesium salts are currently on the market, consumers should be aware of the risks associated with them and should avoid purchasing and using such products,” the agency said.
For a while, however, alternative medicine practitioners in the U.S. did have access to products made with cesium chloride in bulk through compounding pharmacies—pharmacies that create custom-made formulations of drugs. In 2018, the agency effectively blacklisted cesium chloride from being made in compounding pharmacies, though only after a lawsuit was filed against them by the consumer advocacy group Public Citizen. And there are still well-trafficked places online, including Amazon, where retailers appear to sell cesium supplements, some of which are advertised as being made outside of the U.S.
At the time of its decision to blacklist cesium from compounding pharmacies in 2018, the FDA stated that there were at least 23 “serious adverse events” linked to cesium in the medical literature or in reports sent to the FDA itself. These included six deaths, though only two deaths were likely caused in part by the products, according to the agency.