Researchers at Wroclaw Medical University report that acidified sodium chlorite—sold online as “Miracle Mineral Solution” (MMS)—can destroy bacteria and biofilms, but only at concentrations that also damage human cells and may harm beneficial gut microbes. The team warns that homemade mixtures are particularly risky because dosing can vary widely, and it says there is no solid scientific evidence supporting MMS as a treatment for diseases such as cancer, autism or COVID-19.
Miracle Mineral Solution (MMS), promoted online for years as a supposed cure for illnesses including cancer, autism and COVID-19, is a marketing name for sodium chlorite, a disinfectant used in settings such as water treatment. When sodium chlorite is mixed with an acid, it generates chlorine dioxide, a potent bleaching agent that can be dangerous when ingested.
In a study published in Scientific Reports, researchers from Wroclaw Medical University in Poland tested acidified sodium chlorite (ASC) under controlled laboratory conditions using two formulations: one acidified with hydrochloric acid (ASC1) and another acidified with gluconic acid (ASC2). They exposed multiple bacteria to the formulations, including pathogens such as Staphylococcus aureus and Escherichia coli, and a probiotic species, Lactobacillus rhamnosus.
The researchers found that chlorine dioxide could kill bacteria, but that effectiveness came with substantial toxicity. At a concentration of 30 parts per million (0.003%), the bacteria were destroyed, and the team observed disruption of biofilms—protective microbial layers that can make infections harder to treat. At the same concentration, however, tests showed clear damage to human skin cells and high death rates in an in vivo model.
“The results of the study indicate that effective concentrations of ASC against biofilms are also toxic to eukaryotic cells,” said Dr. Ruth Dudek-Wicher of Wroclaw Medical University’s Department of Pharmaceutical Microbiology and Parasitology, adding that researchers could not rule out the possibility that a safer formulation for external use might be developed.
Dudek-Wicher also drew a distinction between professionally produced, purified chlorine dioxide solutions sometimes used in dentistry and unregulated, homemade MMS mixtures promoted online. The study highlighted dosing variability as a major risk, noting that non-standard droppers can produce materially different volumes for the same number of drops.
The work also raised concerns about effects on beneficial bacteria. The researchers reported that biofilms formed by Lactobacillus bacteria were highly sensitive to ASC, which they said could imply risks to the intestinal microflora if the substance is ingested. Dudek-Wicher said the team is not currently planning microbiome studies, “but we do not rule them out in the future,” adding that if a safe oral form of ASC were developed, its impact on the microbiome would need to be analyzed.
Beyond the laboratory findings, the authors argued that MMS is driven by misinformation rather than medicine. “The most harmful mistake is to believe in the effectiveness of MMS without hard scientific evidence,” Dudek-Wicher said. She expressed concern about recommendations that promote MMS for children and pregnant women, and described weight-loss marketing around the product as particularly troubling.
Health authorities have also repeatedly warned consumers not to drink MMS and similar sodium chlorite products. The U.S. Food and Drug Administration has said that when these products are mixed as directed, they can become chlorine dioxide—comparing ingestion to “drinking bleach”—and has cited reports of serious adverse effects such as severe vomiting and diarrhea, life-threatening low blood pressure from dehydration, and acute liver failure.
The Wroclaw team said combating such health myths requires scientific research paired with respectful, empathetic communication. The researchers reported that their findings drew media attention in Poland, including coverage by the Polish Press Agency, and they said they plan additional analyses of other widely promoted but unproven remedies, including DMSO and various “detoxification” protocols.
The study is titled “Antimicrobial properties and toxicity challenges of chlorine dioxide used in alternative medicine” and appears in Scientific Reports (2025, volume 15, issue 1; DOI: 10.1038/s41598-025-01852-z).
