Oregano oil can treat a host of infections, diseases and conditions, according to WebMD. Mixed with a carrier oil, individuals can take oregano oil orally to treat intestinal parasites, allergies, sinus pain and arthritis. Cold and flu, swine flu, earaches, and fatigue are also treatable with oregano oil.
Applied directly to the skin, oregano oil can treat conditions that include acne, athlete's foot, oily skin, dandruff, canker sores and warts. Oregano oil can improve the condition of ringworm, rosacea, psoriasis and insect and spider bites, reports WebMD. Gum disease, toothaches, muscle pain and varicose veins are also treatable with the substance. Oregano oil can repel insects as well, especially mosquitoes.
Oregano oil is quite potent, and use of it can cause serious side effects. Those treating any condition should always dilute it with a carrier oil, according to the Huffington Post.