Is Fenbendazole 500Mg Safe for Humans? Fenbendazole 500 Mg is an antiparasitic medication primarily used in veterinary medicine to treat certain intestinal worm infections in animals. Although it belongs to the benzimidazole class of drugs, which includes medicines used to treat parasitic infections in humans, fenbendazole is not approved for human use in many countries, and its safety and effectiveness in humans have not been...