Co-administering benzimidazole anthelmintics (such as fenbendazole, albendazole, mebendazole, and flubendazole) with fatty food or high-fat meals substantially increases their gastrointestinal absorption and systemic bioavailability.
Because parent benzimidazoles are lipophilic compounds with poor aqueous solubility, taking them on an empty stomach results in minimal baseline absorption1. Lipids in fatty meals act as a solvent in the digestive tract, facilitating dissolution, micellar emulsification, and passive transport across the intestinal mucosa.
Impact Across Specific Benzimidazoles
Albendazole: Taking albendazole with a high-fat meal increases systemic absorption by 5- to 6.5-fold compared with fasted-state administration.
Mebendazole: Co-ingestion with dietary fat increases gastrointestinal absorption more than 5-fold.
Oxfendazole (Primary Active Metabolite of Fenbendazole): Administering oxfendazole alongside a high-fat meal increases peak plasma concentration () by 49% and overall systemic exposure () by 86%.
Flubendazole & Fenbendazole: Taking flubendazole or fenbendazole immediately after meals significantly increases oral absorption and elevates circulating plasma concentration levels3.
Clinical Relevance in Oncology
When benzimidazoles are used for their original indication (targeting gut parasites), low systemic absorption helps keep the active drug concentrated in the intestinal lumen. However, when repurposing these agents for systemic indications like solid tumor oncology, achieving therapeutic plasma levels requires maximizing bioavailability. Taking the medication alongside a high-fat meal—or using engineered lipid-based delivery platforms—helps bridge the solubility gap to reach systemic therapeutic thresholds.
28 Sources
Title: The Antitumorigenic Potentials of Benzimidazole Anthelmintics as Repurposing Drugs
Authors: Deok-Soo Son, Eun-Sook Lee, Samuel E. Adunyah
Journal: Immune Network
Publication Details: 2020, Vol. 20, No. 4, Article e29
DOI: 10.4110/in.2020.20.e29
Title: Teaching an old dog new tricks: The case of Fenbendazole
Authors: Ioanna Vlachou, Panagiotis Parsonidis, Alexandra Mamagkaki, Ioannis Bouris, Ioannis Papasotiriou
Journal: Cancer Treatment and Research Communications
Publication Details: 2022, Vol. 32, Article 100601
DOI: 10.1016/j.ctarc.2022.100601
Title: Redox-mediated Anticancer Activity of Fenbendazole
Authors: Severina Semkova, Boryana Nikolova, Dimitar Ivanov, Georgi Apostolov, Ivan Tsachev, Albena Alexandrova, Rumiana Bakalova, Zdravko Zlatev
Journal: Anticancer Research
Publication Details: 2023, Vol. 43, No. 3, pp. 1207–1212
DOI: 10.21873/anticanres.16267
Title: Fenbendazole inhibits cell proliferation and promotes apoptosis of ovarian cancer cells by inducing mitotic catastrophe
Authors: Xin Wang, Wenda Tian, Na Wang, Xiaoxiao Yang, Lin Lin, Zhaocan Liu, Tian Tian, Chaoyan Wang, Hongying Yang, Yue Jia, Hongping Zhang
Journal: BMC Cancer
Publication Details: 2024, Vol. 24, Article 1593
DOI: 10.1186/s12885-024-13361-9
Title: Cocrystals of Fenbendazole with Enhanced in vitro Dissolution Performance
Authors: K. Blessi Priyanka, T. S. Ramya, K. Swarnalatha, G. Sushmitha, A. Ara, T. S. Srujana, B. Swapna
Journal: European Chemical Bulletin (Eur. Chem. Bull.)
Publication Details: 2023, Vol. 12, Special Issue 8, pp. 9056–9061
DOI: 10.31838/ecb/2023.12.Si8.826
Title: Oral Fenbendazole for Cancer Therapy in Humans and Animals
Authors: Jolie Nguyen, Thai Q. Nguyen, Bo Han, Ba X. Hoang
Journal: Anticancer Research
Publication Details: 2024, Vol. 44, No. 9, pp. 3725–3735
DOI: 10.21873/anticanres.17197
Title: Fenbendazole and Diisopropylamine Dichloroacetate Exert Synergistic Anti-cancer Effects by Inducing Apoptosis and Cell Cycle Arrest in A549 Lung Cancer Cells
Authors: Thai Q. Nguyen, Jolie Nguyen, Bo Han, Ba X. Hoang
Journal: Anticancer Research
Publication Details: 2024, Vol. 44, No. 11, pp. 4761–4772
DOI: 10.21873/anticanres.17302
Title: Ferroptosis Induction by Fenbendazole Combined With Photothermal Therapy Triggers Dual-Immunotherapy Against Bladder Cancer
Authors: Xiaojian Xu, Rui Liang, Anguo Zhao, Jun Zhang, Rongkang Li, Yang Liu, Dashi Deng, Qi Zhuang, Lisha Liu, Lei Peng, Miao Li, Xuedong Wei, Yuhua Huang, Shaohua Zhang, Liang Cheng, Jianquan Hou
Journal: Advanced Science
Publication Details: 2026, Vol. 13, No. 31, Article e2505669 / 74876
DOI: 10.1002/advs.202505669
Title: Case Studies of Patients Who Cured Their Own Stage 4 Cancers
Author: Jacqueline
Publication Platform: Deep Roots at Home
Publication Date: August 14, 2024
URL: deeprootsathome.com/case-studies-of-patients-who-cured-their-own-stage-4-cancers/
Title: Exceptional Repositioning of Dog Dewormer: Fenbendazole Fever
Authors: Tania Sultana, Umair Jan, Hyunsu Lee, Hyejin Lee, Jeong Ik Lee
Journal: Current Issues in Molecular Biology (Curr. Issues Mol. Biol.)
Publication Details: 2022, Vol. 44, No. 10, pp. 4977–4986
DOI: 10.3390/cimb44100338
Title: Fenbendazole acts as a moderate microtubule destabilizing agent and causes cancer cell death by modulating multiple cellular pathways
Authors: Nidhi Dogra, Abhisheak Kumar, Tapas Mukhopadhyay
Journal: Scientific Reports
Publication Details: 2018, Vol. 8, Article 11926
DOI: 10.1038/s41598-018-30158-6
Title: Fenbendazole as a Treatment for Diffuse Large B-Cell Lymphoma
Authors: Anas Abughanimeh, Theujus Evans, Alok Kallam
Journal: Annals of Hematology & Oncology
Publication Details: 2020, Vol. 7, No. 2, Article 1284
Title: From Deworming to Cancer Therapy: Benzimidazoles in Hematological Malignancies
Authors: Udayakumar Golla, Sagar Patel, Nirav Shah, Salvatore Talamo, Rahul Bhalodia, David Claxton, Sinisa Dovat, Arati Sharma
Journal: Cancers
Publication Details: 2024, Vol. 16, No. 20, Article 3454
DOI: 10.3390/cancers16203454
Title: Anticancer role of flubendazole: Effects and molecular mechanisms (Review)
Authors: Xing Xing, Zongning Zhou, Hongwei Peng, Shaoping Cheng
Journal: Oncology Letters
Publication Details: 2024, Vol. 28, No. 6, Article 558
DOI: 10.3892/ol.2024.14691
Title: Screening of Benzimidazole-Based Anthelmintics and Their Enantiomers as Repurposed Drug Candidates in Cancer Therapy
Authors: Rosalba Florio, Simone Carradori, Serena Veschi, Davide Brocco, Teresa Di Genni, Roberto Cirilli, Adriano Casulli, Alessandro Cama, Laura De Lellis
Journal: Pharmaceuticals
Publication Details: 2021, Vol. 14, No. 4, Article 372
DOI: 10.3390/ph14040372
Title: Overcoming cancer therapeutic bottleneck by drug repurposing
Authors: Ying Xia, Ming Sun, Hai Huang, Wei-Lin Jin
Journal: Signal Transduction and Targeted Therapy
Publication Details: 2024, Vol. 9, Article 101
DOI: 10.1038/s41392-024-01808-1
Title: Repurposing of Benzimidazole Anthelmintic Drugs as Cancer Therapeutics
Authors: Bomi Song, Eun Young Park, Kwang Joon Kim, Sung Hwan Ki
Journal: Cancers
Publication Details: 2022, Vol. 14, No. 19, Article 4601
DOI: 10.3390/cancers14194601
Title: From Deworming to Cancer Therapy: Benzimidazoles in Hematological Malignancies
Authors: Udayakumar Golla, Sagar Patel, Nirav Shah, Salvatore Talamo, Rahul Bhalodia, David Claxton, Sinisa Dovat, Arati Sharma
Journal: Cancers
Publication Details: 2024, Vol. 16, No. 20, Article 3454
DOI: 10.3390/cancers16203454
Title: Fenbendazole Enhancing Anti-Tumor Effect: A Case Series
Authors: Ryan S. Chiang, Ali B. Syed, Jonathan L. Wright, Bruce Montgomery, Sandy Srinivas
Journal: Clinical Oncology: Case Reports
Publication Details: 2021, Vol. 4, No. 2, Article 1000159
Title: Flubendazole Plays an Important Anti-Tumor Role in Different Types of Cancers
Authors: Chaoran Chen, Yueming Ding, Huiyang Liu, Mengyao Sun, Honggang Wang, Dongdong Wu
Journal: International Journal of Molecular Sciences (Int. J. Mol. Sci.)
Publication Details: 2022, Vol. 23, No. 1, Article 519
DOI: 10.3390/ijms23010519
Title: Unexpected Antitumorigenic Effect of Fenbendazole When Combined with Supplementary Vitamins
Authors: Peng Gao, Chi V. Dang, John Watson
Journal: Journal of the American Association for Laboratory Animal Science (J. Am. Assoc. Lab. Anim. Sci. / JAALAS)
Publication Details: 2008, Vol. 47, No. 6, pp. 37–40
Title: Fenbendazole Exhibits Antitumor Activity Against Cervical Cancer Through Dual Targeting of Cancer Cells and Cancer Stem Cells: Evidence from In Vitro and In Vivo Models
Authors: Xi Lei, Yi Wang, Yuanyuan Chen, Jinyue Duan, Xin Gao, Zhongyi Cong
Journal: Molecules
Publication Details: 2025, Vol. 30, No. 11, Article 2377
DOI: 10.3390/molecules30112377
Title: Evaluation of the Drug–Polymer Compatibility and Dissolution Behaviour of Fenbendazole–Soluplus® Solid Dispersions Prepared by Hot-Melt Extrusion
Authors: Amirhossein Karimi, Gilberto S. N. Bezerra, Clement L. Higginbotham, John G. Lyons
Journal: Polymers
Publication Details: 2026, Vol. 18, No. 3, Article 333
DOI: 10.3390/polym18030333
Title: Drug repurposing from the perspective of pharmaceutical companies
Authors: Y. Cha, T. Erez, I. J. Reynolds, D. Kumar, J. Ross, G. Koytiger, R. Kusko, B. Zeskind, S. Risso, E. Kagan, S. Papapetropoulos, I. Grossman, D. Laifenfeld
Journal: British Journal of Pharmacology (Br. J. Pharmacol.)
Publication Details: 2018, Vol. 175, No. 2, pp. 168–180
DOI: 10.1111/bph.13858
Title: Screening of Benzimidazole-Based Anthelmintics and Their Enantiomers as Repurposed Drug Candidates in Cancer Therapy
Authors: Rosalba Florio, Simone Carradori, Serena Veschi, Davide Brocco, Teresa Di Genni, Roberto Cirilli, Adriano Casulli, Alessandro Cama, Laura De Lellis
Journal: Pharmaceuticals
Publication Details: 2021, Vol. 14, No. 4, Article 372
DOI: 10.3390/ph14040372
Title: Repositioning of the anthelmintic drug mebendazole for the treatment for colon cancer
Authors: Peter Nygren, Mårten Fryknäs, Bengt Ågerup, Rolf Larsson
Journal: Journal of Cancer Research and Clinical Oncology
Publication Details: 2013, Vol. 139, No. 12, pp. 2133–2140
DOI: 10.1007/s00432-013-1539-5
Title: Fenbendazole acts as a moderate microtubule destabilizing agent and causes cancer cell death by modulating multiple cellular pathways
Authors: Nidhi Dogra, Abhisheak Kumar, Tapas Mukhopadhyay
Journal: Scientific Reports
Publication Details: 2018, Vol. 8, Article 11926
DOI: 10.1038/s41598-018-30158-6
Title: Synergistic anti-tumor effect of fenbendazole and diisopropylamine dichloroacetate in immunodeficient BALB/c nude mice transplanted with A549 lung cancer cells
Authors: Thai Q. Nguyen, Uyen T. T. Phan, Mao V. Can, Dang H. Nguyen, Bo Han, Ba X. Hoang
Journal: Translational Lung Cancer Research (Transl. Lung Cancer Res.)
Publication Details: 2025, Vol. 14, No. 7, pp. 2509–2521
DOI: 10.21037/tlcr-2024-1272