The National Cancer Institute (NCI) announced on Jan. 30 that it has initiated a focused preclinical examination of ivermectin’s reported ability to kill cancer cells, a move NCI Director Anthony Letai said the agency is treating seriously and expects preliminary results from in a few months. The remark came at a Washington, D.C. event where NIH leaders spoke about a broader openness to unconventional research ideas. The announcement, however, has drawn sharp concern from long-serving NCI scientists worried about taxpayer funds and research priorities. The institute has not disclosed the study’s budget, lead investigators, or any specific new evidence that prompted this inquiry.
- NCI confirmed a targeted preclinical study of ivermectin’s anticancer effects; preliminary results are expected in a few months, according to Director Anthony Letai.
- Letai, who was appointed NCI director in September, made the comments at a Jan. 30 event titled “Reclaiming Science: The People’s NIH.”
- Career scientists at NCI have expressed alarm; one anonymous researcher told reporters the effort diverts funds from promising projects.
- There is no accepted clinical evidence that ivermectin treats cancer in humans; a small trial in metastatic breast cancer showed no clear benefit when ivermectin was added to immunotherapy.
- Ivermectin is FDA‑approved for certain parasitic infections and topical uses; the agency warns that large doses can cause seizures, coma, or death.
- During COVID-19, ivermectin’s profile rose due to fringe promotion; a January 2025 podcast episode mentioning ivermectin exceeded 12 million views.
- About three-quarters of NCI funding is awarded to outside investigators, leaving open whether this work is in-house or externally contracted.
Background
Ivermectin is an antiparasitic drug with established approvals for some human and veterinary uses and a Nobel-linked history tied to parasite control. Laboratory research over the past decade has shown that ivermectin can induce cell death and slow tumor cell growth in cell cultures and some animal models, prompting sporadic curiosity about repurposing it for oncology. The drug also became politically and culturally charged during and after the COVID-19 pandemic, when online communities and some commentators promoted it for unproven indications, elevating public demand and scrutiny.
The current NCI step follows a Jan. 30 forum in Washington where NIH officials framed a posture of examining hypotheses that the broader scientific establishment had previously dismissed. That framing is tied to a policy environment that, since the prior administration’s turnover, has emphasized openness to off‑label and low‑cost therapeutics. Advocacy from groups aligned with the MAHA agenda and certain state initiatives — including plans in Florida to support ivermectin research — has intensified public attention and pressure on federal agencies.
Main Event
At the Jan. 30 event, Anthony Letai said the institute “did engage in a better preclinical study” of ivermectin and its purported cancer‑killing properties, adding that the work is being taken “seriously” and that results would likely follow within months. NIH Director Jay Bhattacharya, who spoke at the same event, said the agency has an obligation to examine ideas that influence public health, especially when they attract strong public interest. Neither official provided specifics about experimental design, funding amounts, or the institutional unit leading the studies.
The announcement provoked immediate pushback from career NCI scientists, some of whom asked to speak anonymously because they are not authorized to discuss internal matters. One long‑standing researcher described reallocating funds to the preclinical work as diverting support from more promising lines of inquiry, calling the decision “absurd” and “appalling.” NCI and HHS did not supply KFF Health News with details on the study’s budget or investigators when asked.
Experts outside the agency noted that preclinical work is a routine, early step to test biological plausibility and safety signals in controlled lab settings before any clinical trials. Still, clinicians and researchers warned that public perception of such work can be misleading: positive results in cell cultures or animal models frequently fail to translate into safe, effective human treatments. Physicians reported encountering patients who, influenced by social media or celebrity anecdotes, have already sought or used ivermectin instead of standard cancer care.
Analysis & Implications
The NCI’s decision sits at the intersection of science, politics, and public trust. On one hand, systematic preclinical evaluation is a standard scientific response to repeated claims and public interest; testing a widely available compound for anticancer activity could identify unexpected biology or lead compounds. On the other hand, selective research choices driven by political or popular pressure risk skewing limited resources away from investigator‑driven, peer‑reviewed priorities that have stronger prior evidence.
Resource allocation is a pragmatic concern: the institute has finite funds and a portfolio of projects with established translational pathways. If NCI redirects meaningful dollars toward exploratory studies prompted primarily by public advocacy rather than a clear scientific signal, career researchers argue that the opportunity cost could be substantial, especially for early‑stage investigators and long‑term disease programs.
Clinically, the lack of convincing human data means any laboratory signals must be treated as hypothesis‑generating, not practice‑changing. Regulators and clinicians emphasize that preclinical promise often does not survive the rigors of randomized trials. Meanwhile, the public conversation around ivermectin illustrates how social media and high‑profile endorsements can push patients toward unproven treatments, sometimes with harmful consequences, complicating clinician efforts to maintain evidence‑based care.
Comparison & Data
| Study Stage | Typical Goal | Current Ivermectin Evidence |
|---|---|---|
| Preclinical | Assess mechanisms, cytotoxicity, and animal efficacy | Laboratory studies show cell death and tumor growth inhibition in vitro/animals |
| Early clinical trials | Test safety and preliminary efficacy in humans | Limited small trials; one metastatic breast cancer study found no clear benefit |
| Real‑world use | Off‑label or nonprescribed use by patients | Anecdotal reports and case harms, including at least one documented neurotoxicity event |
The table summarizes the gap between laboratory signals and human evidence. While in vitro and animal findings justify mechanistic curiosity, the jump to human benefit requires phased clinical trials with robust endpoints and safety monitoring. Regulators note that ivermectin is approved for certain parasitic indications but not for cancer; large doses carry documented toxicity risks.
Reactions & Quotes
“We’ll probably have those results in a few months… So we are taking it seriously.”
Anthony Letai, NCI Director (spoken Jan. 30)
Letai framed the work as a measured, preclinical inquiry rather than an endorsement for clinical use. His comment was delivered alongside broader remarks about studying ideas that draw public attention.
“If lots of people believe it and it’s moving public health, we as NIH have an obligation, again, to treat it seriously.”
Jay Bhattacharya, NIH Director (spoken Jan. 30)
Bhattacharya linked the decision to an institutional responsibility to respond when public belief is shaping health behavior, a stance that some scientists view as conflating popularity with scientific priority.
“I am shocked and appalled… We are moving funds away from so much promising research in order to do a preclinical study based on nonscientific ideas.”
Anonymous long‑serving NCI scientist (to reporters)
That reaction captures internal concern about research prioritization and the perceived influence of political or public pressure on agency decisions.
Unconfirmed
- Exact budget and funding source for the NCI’s ivermectin preclinical study remain undisclosed by HHS and NCI.
- Whether the experiments are being performed by in‑house NCI teams or contracted to external investigators has not been confirmed.
- No new peer‑reviewed evidence has been published that clearly prompted the NCI to open this specific preclinical line of inquiry.
- Claims that ivermectin is a broadly effective cancer treatment in humans remain unsupported by randomized clinical trials.
Bottom Line
The NCI’s decision to perform preclinical work on ivermectin reflects a tension between responding to public interest and adhering to conventional scientific prioritization. Preclinical study is a logical, contained scientific step when repeated claims emerge; it does not imply that ivermectin is effective against cancer in people. Researchers and clinicians caution that laboratory activity should be communicated carefully to avoid fostering false hopes or encouraging patients to forgo established, effective therapies.
Key things to watch in the coming months are the study’s methodology, who is conducting the experiments, and whether any peer‑reviewed preclinical results are made public. If laboratory findings are compelling, the appropriate next steps would be rigorously designed early‑phase human trials with clear safety oversight — not immediate clinical adoption. Until then, oncologists urge patients to rely on proven treatments and to discuss any interest in off‑label options with their care teams.