The most powerful antibacterial essential oils because it contains carvacrol and thymol, two antibacterial and antifungal compounds. In fact, research shows oregano oil is effective against many clinical strains of bacteria, including Escherichia coli (E to use natural antibiotic, you can mix it with water or coconut oil. The dosage depends on the condition you're treating, but remember to take only very small amounts at a time—about 1-2 drops.