I was curious if these had been looked at for Liver cancer and apparently they have, though Fenbendazole may have some concerns from self administration activities:
Fenbendazole
In liver cancer models:
Fenbendazole has been tested directly against hepatocellular carcinoma cells (H4IIE rat liver cancer line), where it suppressed growth and induced apoptosis via p21‑mediated cell‑cycle arrest.
So yes—there are studies of fenbendazole specifically in liver cancer models, but as an anticancer agent, not as a carcinogen.
Liver toxicity in humans:
There are now case reports of severe drug‑induced liver injury (DILI) from self‑administered veterinary fenbendazole in cancer patients and others, with marked jaundice and hepatocellular injury that improved after stopping the drug.
That’s liver damage, not liver cancer—but it’s a serious signal that high‑dose, unsupervised use can be dangerous.
Ivermectin
In liver cancer–type settings:
Ivermectin has been studied in cholangiocarcinoma (a bile duct cancer in the liver), including gemcitabine‑resistant cell lines, where it inhibited proliferation and induced cell death in vitro.
Again, that’s an anticancer context involving liver/biliary cancers.
Liver toxicity:
Hepatotoxicity from ivermectin appears rare and usually mild, with isolated case reports of reversible hepatitis.
No evidence that ivermectin induces liver cancer in humans.
Mebendazole
Cancer studies:
Mebendazole is in the same benzimidazole family and has been explored in multiple tumor types (glioma, colon, etc.). Like fenbendazole, it’s being repurposed mainly for its microtubule‑disrupting, pro‑apoptotic effects in cancer cells.
Liver angle:
Data on mebendazole and liver cancer specifically are much thinner than for fenbendazole/ivermectin. It shares class‑related concerns about potential liver enzyme elevations, but I couldn’t find convincing evidence that mebendazole is linked to causing liver cancer in humans.
https://link.springer.com/article/10.1007/s11912-025-01704-z?utm_source=copilot.com
https://europepmc.org/article/MED/31519586?utm_source=copilot.com
https://www.jstage.jst.go.jp/article/bpb/45/2/45_b21-00697/_html/-char/en?utm_source=copilot.com
Marq