Myrrh is an effective anti-microbial agent that has been shown to work in two complementary ways. Primarily it stimulates the production of white blood corpuscles (with their anti-pathogenic actions) and secondarily it has a direct anti-microbial effect. Thus the herb will aid and support the natural process of defence, a vital activity, as so oftern today antibiotic drugs do this work for the body. Myrrh may be used in a wide range of conditions where an anti-microbial agent is needed. It finds specific use in the treatment of infections in the mouth such as mouth ulcer, gingivitis, pyorrhoea , as well as the catarrhal problems of pharyngitis and sinusitis. It is often used as part of an approach to the treatment of the common cold. The New Holistic Herbal by David Hoffmann Pg. 218