The fenbendazole controversy was an incident in which inaccurate claims about the efficacy of fenbendazole, an anthelmintic primarily used to treat various parasitic infections in dogs, in curing terminal lung cancer gained widespread attention among patients.[1] This situation originated with the assertions made by an American cancer patient named Joe Tippens but garnered significant attention, particularly in South Korea. It resulted in nationwide confusion and a surge in the demand for fenbendazole at pharmacies throughout South Korea.
However, it's important to note that Joe Tippens had participated in a clinical trial involving Keytruda, an immunotherapy drug, at the MD Anderson Cancer Center. His reported improvement was likely attributable to the effects of this immunotherapy rather than fenbendazole itself. Initially, South Korean health authorities and experts had issued warnings about potential side effects through press releases on September 23, 2019, but patients chose to disregard these warnings.
Instead, public interest was drawn to a well-known Korean comedian who publicly expressed his intention to use fenbendazole through social media on September 24, 2019, while battling lung cancer. However, by September 2020, this celebrity stated that he would no longer use or endorse fenbendazole, and tragically, he passed away in December 2021.
Indeed, some in-vitro studies have found that fenbendazole has the potential to slow cancer cell growth.[2] However, these are in-vitro studies, meaning they were completed in a petri-dish (glass container), rather than in an animal or human. Unfortunately, results from in-vitro studies are very rarely replicated when carried out in animals or humans. As for research in humans - there is currently no data available on its safety and effectiveness in those with cancer. As for animal-based research - the only study on fenbendazole and cancer was a 2012 study which found that fenbendazole did not affect tumor growth, invasion, or metastasis.[3] Even if there were some positive animal studies as well - this would not be considered enough evidence to support its use in humans as promising research from animal studies is often not replicated in humans.
There are only two small clinical studies that have been completed in humans to treat parasites, listed on the world’s largest medical database - PUBMED.[4] However, these studies were in the context of treating parasites, not cancer. Furthermore, both studies are very small and are from 1970-1980. Outside of these, the safety and effectiveness of the drug has not been adequately tested, and has never been tested on people with cancer.
The Food and Drug Administration (FDA) and European Medicines Agency (EMA) both prohibit fenbendazole for human use. The dose used in animals is greater than 100 fold of the amount that is considered safe for human intake. This is because research has shown risk of serious side effects, such as hepatitis, bleeding and death.[5],[6].
While laboratory research (in-vitro and animal-based) and anecdotal reports may generate interest in using fenbendazole for cancer, it is essential to rely on evidence-based treatments for cancer. Many popular therapies can appear promising at first, but when studied in larger groups of people often fail to show benefit. There is currently a wealth of information on natural therapies already available, with over 50,000 research studies completed in humans with cancer as of 2023. Some of these options have over 100+ studies demonstrating their benefit and safety. At our clinic, we always start with the natural options with the greatest potential for benefit based on the available data.
Patients should always consult with their oncologists or healthcare providers to explore the most appropriate and effective treatment options based on their specific cancer type, stage, and individual health conditions. Research continues to investigate fenbendazole’s potential role in cancer therapy, but until more conclusive evidence emerges, it should not be used as a treatment for cancer.
[1] Kim JH, Oh KH, Shin HY, Jun JK. How cancer patients get fake cancer information: From TV to YouTube, a qualitative study focusing on fenbendazole scandle. Front Oncol. 2022 Oct 28;12:942045. doi: 10.3389/fonc.2022.942045. PMID: 36387110; PMCID: PMC9650234. [2]https://pubmed.ncbi.nlm.nih.gov/?term=%28fenbendazole%5BTitle%2FAbstract%5D%29+AND+%28cancer%5BTitle%2FAbstract%5D%29 [3] Duan Q, Liu Y, Booth CJ, Rockwell S. Use of fenbendazole-containing therapeutic diets for mice in experimental cancer therapy studies. J Am Assoc Lab Anim Sci. 2012 Mar;51(2):224-30. PMID: 22776123; PMCID: PMC3314526. [4]https://pubmed.ncbi.nlm.nih.gov/?term=fenbendazole%5BTitle%2FAbstract%5D&filter=pubt.clinicaltrial&filter=pubt.meta-analysis&filter=hum_ani.humans&sort=date&size=200 [5] Drug-Induced Liver Injury in a Patient with Nonsmall Cell Lung Cancer after the Self-Administration of Fenbendazole Based on Social Media Information. Subject Area: Oncology. Teppei Yamaguchi; Junichi Shimizu; Yuko Oya; Yoshitsugu Horio; Toyoaki Hida Case Rep Oncol (2021) 14 (2): 886–891. Link [6] Cray C, Altman NH. An Update on the Biologic Effects of Fenbendazole. Comp Med. 2022 Aug 1;72(4):215-219. doi: 10.30802/AALAS-CM-22-000006. Epub 2022 Jun 28. PMID: 35764389; PMCID: PMC9413524.