Ivermectin Promoted as Cancer Cure Despite Lack of Evidence, Scientists Warn
A deworming drug intended for animals is being widely promoted on social media as a cancer treatment, but researchers say there is no scientific evidence it works in humans and a recent viral study had serious methodological flaws.
Ivermectin, a deworming medication typically used to treat parasites in livestock and pets, has become the focus of renewed health misinformation claims, with influencers and alternative health communities promoting it as a cancer cure despite a lack of scientific evidence backing such use.
The resurgence centres on a June 2026 study that gained significant traction online — particularly on X (formerly Twitter) — before and after its official publication. The research was downloaded more than 85,000 times in the pre-publication phase and spread rapidly through social media and alternative health networks, where it was cited to support broader claims about repurposing antiparasitic drugs as cancer treatments. The U.S. Food and Drug Administration has not approved ivermectin for cancer use.
Study Raises Red Flags
Shortly after the study's publication, the scientific community flagged serious concerns about its methodology, potential conflicts of interest, and the peer-review process used to evaluate it. The journal later issued an Expression of Concern, but the paper has not been retracted.
According to reporting by The Conversation, the study had critical limitations. It lacked a comparison group to determine whether patients taking ivermectin alongside another antiparasitic drug actually improved because of those treatments — or because of the conventional cancer therapies they were simultaneously receiving. The research also relied on patients' self-reported outcomes rather than independently verifiable medical records, a choice that makes findings more susceptible to bias and less reliable as scientific evidence.
The renewed attention surrounding ivermectin offers a case study in how early findings spread faster than the evidence needed to evaluate them.
How Misinformation Spreads
This pattern — early findings circulating widely before scientists fully understand their validity — reflects a structural challenge in science communication. Traditional news outlets covered the renewed public interest in ivermectin for cancer following the COVID-19 pandemic, but much of the actual conversation about this particular study occurred outside mainstream media coverage, within online communities where claims are often accepted with minimal scrutiny.
By the time the scientific community raises concerns or additional evidence emerges — a process that can take months or years — many people have already shared the original report or made financial and medical decisions based on it. The speed of social media amplification often outpaces the pace of scientific verification.
A Broader Pattern
Repurposing existing medications for new therapeutic uses, including cancer treatment, has a legitimate history in medicine. Antiparasitic drugs like ivermectin have attracted growing research interest for their potential in this space. However, laboratory studies on cell cultures — which often show promising early signals — do not automatically translate to safe or effective treatments in humans. That gap between lab findings and human efficacy remains a significant and often overlooked step in drug development.
Researchers studying health communication note that this case highlights why clarity about what scientific evidence actually shows — and where it falls short — matters for public health. Distinguishing between preliminary findings, methodological concerns, and established safety or efficacy helps readers avoid making medical decisions based on incomplete or flawed information.