WeeklySA_AdminINTEREST: United States’ government cancer researchers launch a preclinical study into ivermectin’s tumour-killing potential – and face backlash from career scientists who question the evidence…
By Rachana Pradhan
The National Cancer Institute (NCI), the federal agency leading America’s fight against cancer, has launched a preclinical study into whether ivermectin — a decades-old anti-parasitic drug — can kill cancer cells.
The announcement, made by NCI Director Dr Anthony Letai at a January 30 event in Washington, DC, has triggered both curiosity and concern inside the scientific community.
“There are enough reports of it, enough interest in it, that we actually did — ivermectin, in particular — engage in a better preclinical study of its properties and its ability to kill cancer cells,” Letai said. “We’ll probably have those results in a few months. So we are taking it seriously.”
Letai spoke at an event hosted by the MAHA Institute under the “Make America Healthy Again” banner promoted by Health and Human Services Secretary Robert F. Kennedy Jr. NIH Director Jay Bhattacharya also participated, describing the agency’s renewed openness to exploring ideas that some scientists have previously dismissed.
If lots of people believe it (ivermectin), and it’s moving public health,
we as NIH have an obligation to treat it seriously…
“If lots of people believe it, and it’s moving public health, we as NIH have an obligation to treat it seriously,” Bhattacharya said.
The decision to study ivermectin as a potential cancer therapy has unsettled some career scientists at NCI, who argue there is insufficient evidence to justify diverting funds from other promising research.
“I am shocked and appalled,” said one NCI scientist who requested anonymity for fear of retaliation. “We are moving funds away from so much promising research in order to do a preclinical study based on nonscientific ideas. It’s absurd.”
A Drug With a Complex Reputation
Ivermectin is FDA-approved to treat certain parasitic infections in humans and animals. It is widely used to treat conditions caused by parasitic worms, lice and rosacea. Two scientists involved in its discovery were awarded the Nobel Prize in 2015 for its impact in combating parasitic diseases.
However, ivermectin gained controversial prominence during the COVID-19 pandemic, when fringe medical groups and online influencers promoted it as a treatment despite clinical trials finding no benefit against the virus.
Since then, the drug has become a symbol of resistance to mainstream medicine among some conservative and MAHA-aligned communities. Supporters argue that inexpensive, off-patent drugs like ivermectin have been overlooked or suppressed by pharmaceutical companies due to limited profit potential.
Kennedy has publicly accused federal regulators of suppressing treatments that cannot be patented. In an October 2024 social media post, he criticised what he described as the FDA’s “aggressive suppression” of ivermectin and other alternative therapies.
The Department of Health and Human Services maintains that NIH remains committed to “rigorous, gold-standard research.” However, neither HHS nor NCI responded to questions about how much taxpayer funding is being allocated to the ivermectin study, who is conducting it, or what new evidence prompted the research.
What Is a Preclinical Study?
The current investigation is preclinical — meaning it is being conducted in laboratories rather than in humans.
Such studies typically involve experiments in cell cultures or animals to determine whether a drug shows promise and whether it may cause harm before human trials begin.
Previous laboratory research has suggested ivermectin may promote cancer cell death and inhibit tumour growth under certain conditions. Letai acknowledged that the drug has been studied before, both with NIH funding and outside it.
But evidence of effectiveness in humans remains absent.
A small clinical trial testing ivermectin in combination with immunotherapy for one type of metastatic breast cancer found no significant benefit from adding the drug.
“That’s the key distinction,” said Dr Jeffery Edenfield, executive medical director of oncology at Prisma Health Cancer Institute in South Carolina. “Many, many, many things work in a test tube. Quite a few things work in a mouse or a monkey. It still doesn’t mean it’s going to work in people.”
Patient Safety Concerns
Oncologists report increasing numbers of patients asking about ivermectin, often influenced by social media or celebrity endorsements.
Edenfield said he regularly fields questions about the drug and has persuaded at least one patient to stop using it.
He also described a colleague whose patient chose to forgo highly effective standard cancer therapy in favour of ivermectin.
“People come to the discussion having largely already made up their minds,” he said. “We’re in this delicate time when there’s a fundamental mistrust of medicine.”
The risks are not theoretical. A June letter from clinicians at Cincinnati Children’s Hospital Medical Centre described an adolescent patient with metastatic bone cancer who began taking ivermectin after seeing online claims about its benefits. The patient experienced neurotoxicity — including nausea and fatigue — and required emergency care.
The FDA has warned that high doses of ivermectin can be dangerous. Overdoses may cause seizures, coma or death.
Some physicians worry that the federal government’s involvement in studying ivermectin could unintentionally reinforce public belief that it is already proven effective.
“When celebrities say it cured stage 4 cancer, that message travels much faster than nuance,” Edenfield said.
In January 2025, actor Mel Gibson claimed on Joe Rogan’s podcast that ivermectin helped cure three friends with advanced cancer. The episode has been viewed more than 12 million times.
Political and Policy Dimensions
The renewed focus on ivermectin comes amid broader changes at NIH under the current administration. Bhattacharya recently said he wants NIH to function as “the research arm of MAHA,” signalling a shift toward investigating ideas that resonate with certain political constituencies.
Meanwhile, several states have moved to make ivermectin available over the counter. Florida has announced plans to fund research into the drug as a potential cancer treatment, though details remain sparse.
One NCI scientist pushed back on the notion that the agency had previously ignored off-label drugs.
“This is not a new idea they came up with,” the scientist said. “NIH has always studied repurposed drugs when there’s credible evidence.”
Letai, formerly an oncologist at Dana-Farber Cancer Institute, did not clarify whether the ivermectin study is being conducted internally or through external grants. Roughly three-quarters of NCI’s research funding goes to outside institutions.
He also cautioned against inflated expectations. “At least on a population level,” Letai said, “it’s not going to be a cure-all for cancer.”
Science, Trust and Expectations
The controversy surrounding ivermectin underscores a broader tension between public belief and scientific process.
Supporters argue that NIH should investigate widely discussed treatments rather than dismiss them outright. Critics counter that taxpayer-funded research must prioritise ideas grounded in strong preliminary evidence.
Preclinical results are expected within months. Until then, oncologists stress that patients should rely on treatments proven safe and effective in rigorous clinical trials.
Science advances by testing hypotheses — but not all hypotheses bear fruit.
For cancer patients, the stakes could not be higher. – Science X
