Question explored with the scientific record
Conversation so far
- 1 Ivermectin and fenvandozole to treat renal cell carcinoma
- 2 Why is everyone on the internet saying it works?
Answered on this page ↓
Why is everyone on the internet saying it works?
The short version: the internet is full of people saying it works because the preclinical biology is genuinely interesting, but no human trial has tested either drug against renal cell carcinoma, and the safety data from other uses is not reassuring.
The evidence you see online is mostly coming from the same handful of lab studies. Ivermectin has been shown to kill cancer cells in a dish through multiple mechanisms: it blocks the Wnt signaling pathway that drives many cancers [4], it triggers mitochondrial dysfunction and oxidative stress in glioblastoma cells [6], and it induces a rapid inflammatory cell death in breast cancer cells through P2X4/P2X7 receptors [5]. A 2026 study even showed that wrapping ivermectin in a platelet-membrane coating improved its delivery to breast tumors in mice [2]. These are real biological effects, and they are why people get excited.
But there is a massive gap between a mouse tumor and a human patient. The concentrations that kill cancer cells in the lab are in the low micromolar range [4, 6], which is far higher than what you can safely achieve in a human bloodstream with standard oral doses. The one human trial of ivermectin for severe COVID-19 found no benefit and numerically more adverse events in the ivermectin group [7]. A pharmacovigilance analysis found a 3-fold increase in severe skin reactions compared to other drugs [3]. For fenbendazole, the animal data is actually concerning: a rat study found it acted as a liver tumor promoter, increasing pre-cancerous lesions in a dose-dependent way [1].
| Drug | What the evidence shows for cancer | Human trial for RCC? |
|---|---|---|
| Ivermectin | Kills cancer cells in lab dishes and mouse models via Wnt inhibition, mitochondrial dysfunction, and P2X receptor activation [4, 5, 6] | None |
| Fenbendazole | Acts as a liver tumor promoter in rats exposed to a carcinogen [1] | None |
The internet is not lying about the lab data. It is skipping the part where lab data does not translate to human benefit without a trial. The burden of proof is on the person proposing the treatment, and that burden has not been met.
My call: the preclinical biology is real but does not justify treating renal cell carcinoma in humans. Confidence: high.
Sources used 7
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A human case of Dioctophyma renale (giant kidney worm) accompanied by renal cancer and a retrospective study of dioctophymiasis
Describes a rare human case of Dioctophyma renale with concurrent renal cancer and provides the first retrospective synthesis of dioctophymiasis cases worldwide to outline epidemiology, clinical features, and diagnostic/treatment gaps.
DOI: 10.1051/parasite/2019023 -
Biomimetic platelet-membrane camouflaged ivermectin nanocrystals for tumor homing and breast cancer management
The study develops biomimetic platelet-membrane camouflaged ivermectin nanocrystals (PMV/Ivm-NC) using a sonoprecipitation method and platelet membrane coating to achieve targeted tumor homing, immunogenic cancer cell death, and enhanced antitumor/antimetastatic effects against …
DOI: 10.1007/s13346-025-02032-2 -
Cytogenetic characterization of a familial papillary renal cell carcinoma
This study presents the cytogenetic characterization of familial papillary renal cell carcinoma in two patients from the same family, revealing specific chromosomal alterations and suggesting a hereditary basis for the disease.
DOI: 10.1016/0165-4608(95)00044-5 -
The river blindness drug I vermectin and related macrocyclic lactones inhibit WNT ‐ TCF pathway responses in human cancer
This study identifies Ivermectin and related macrocyclic lactones as effective inhibitors of the WNT-TCF signaling pathway in human cancer cells, suggesting their potential therapeutic use against various cancers.
DOI: 10.15252/emmm.201404084 -
Modulation of P2X4/P2X7/Pannexin-1 sensitivity to extracellular ATP via Ivermectin induces a non-apoptotic and inflammatory form of cancer cell death
Augmenting extracellular ATP signaling through P2X4/P2X7/Pannexin-1 with Ivermectin drives a rapid, inflammatory cancer cell death in breast cancer cells, combining necrotic/pyroptotic and apoptotic pathways via ROS/CaMKII/MPTP and autophagy, with immunogenic-cell-death hallmark…
DOI: 10.1038/srep16222 -
Anthelmintic drug ivermectin inhibits angiogenesis, growth and survival of glioblastoma through inducing mitochondrial dysfunction and oxidative stress
Ivermectin, a repurposed antiparasitic, inhibits glioblastoma cell growth and angiogenesis by inducing mitochondrial dysfunction and oxidative stress, while concurrently suppressing the Akt/mTOR signaling axis in tumor and endothelial cells, with supporting in vivo xenograft dat…
DOI: 10.1016/j.bbrc.2016.10.064 -
Clinical efficacy and safety of ivermectin (400 ug/kg, single dose) in patients with severe COVID-19: a randomized clinical trial
Among hospitalized adults with severe COVID-19, adding a single 400 μg/kg dose of ivermectin to standard care, compared with placebo, produced no significant difference in 21-day ICU admission, invasive mechanical ventilation, mortality, or adverse events.
DOI: 10.22354/24223794.1105