Ivermectin is a medication used to treat parasite infestations. In humans, these include head lice, scabies, river blindness (onchocerciasis), strongyloidiasis, trichuriasis, ascariasis, and lymphatic filariasis. In veterinary medicine, it is used to prevent and treat heartworm and acariasis, among other indications. It can be taken by mouth or applied to the skin for external infestations. It belongs to the avermectin family of medications. It works through many mechanisms of action that result in death of the targeted parasites.