Ivermectin's Unproven Comeback: From COVID-19 Misinformation to Cancer Treatment Claims

Ivermectin, an antiparasitic drug, is experiencing a resurgence in use, particularly among cancer patients, despite a lack of scientific evidence supporting its efficacy for cancer treatment.

Originally discovered in the 1970s, ivermectin is effective against parasitic infections such as roundworm, lice, and scabies. It has been instrumental in reducing cases of river blindness globally, earning it the reputation of a "wonder drug" in public health.

A Drug with a History: From Parasites to Pandemic

During the COVID-19 pandemic, ivermectin gained prominence as a purported treatment for the virus, fueled by misinformation. Numerous studies subsequently confirmed its ineffectiveness against COVID-19. Despite this, its use surged, with prescriptions increasing tenfold beyond pre-pandemic levels, especially in the Southern U.S. and among older patients.

The Current Surge: Misinformation and Distrust

The drug's current comeback is driven by ongoing misinformation and increasing distrust in traditional health institutions and pharmaceutical companies, particularly within conservative political circles. This has led to its promotion as a "cure-all" for various ailments, including cancer.

Five state legislatures (Tennessee, Arkansas, Idaho, Louisiana, and Texas) have approved measures to make ivermectin available over-the-counter.

This legislative push concerns medical professionals due to risks of overuse, misuse, and the substitution of ivermectin for evidence-based treatments.

Dr. John Mafi, a geriatrician at UCLA who tracks ivermectin prescriptions, noted a decline in use in 2023, followed by a pickup in 2024 and 2025. He attributes this to continued disinformation and political motivations, rather than medical evidence.

Medical Professionals Raise Alarms

Ivermectin can cause side effects in humans, including dizziness, nausea, and itchy skin. The Food and Drug Administration (FDA) warns that excessive doses can potentially lead to coma or death.

The National Cancer Institute initiated preclinical studies on ivermectin's potential to kill cancer cells, although medical experts express low expectations for its effectiveness in humans. Florida's First Lady Casey DeSantis has also mentioned ivermectin in discussions about cancer research funding. However, current research does not support ivermectin as an effective cancer treatment in humans, and more advanced immunotherapies exist.

The Cancer Connection: Patient Inquiries and Dangerous Choices

Oncologist Jonathan Mizrahi in New Orleans has observed a significant increase in cancer patients inquiring about ivermectin, with nearly half of his new patients asking about it within the last year. This trend intensified after actor Mel Gibson suggested on a podcast that ivermectin cured three friends of advanced cancer.

Mizrahi reports that some patients, influenced by such claims and a general mistrust of mainstream medicine, have chosen to forgo proven cancer treatments in favor of ivermectin, sometimes with detrimental outcomes.

He observed one patient whose Stage 4 cancer spread after refusing chemotherapy for ivermectin and fenbendazole.

The Roots of Politicization

The politicization of ivermectin began early in the pandemic. Spanish researcher Carlos Chaccour noted that initial interest in testing ivermectin against COVID-19 was logical, given its history as an effective and accessible drug. However, a small company, Surgisphere, falsely claimed to have data supporting ivermectin's efficacy against COVID-19, leading several Latin American countries to approve and distribute it prematurely. Surgisphere's research was later retracted and discredited.

Conservative media figures in early 2021 further amplified ivermectin's promotion in the U.S. The FDA's 2021 social media warning against using ivermectin —

"You are not a horse. You are not a cow. Seriously, y'all. Stop it."

— contributed to the polarization around the drug, a post later removed following a lawsuit. Chaccour suggests the FDA's tone exacerbated political tensions. He hopes for a future where both sides recognize a shared interest in health to depoliticize the drug, which remains a vital global health tool when used appropriately.