Marjoram has been traditionally used for coughs and other respiratory illnesses. Although an Origanum species oil, it is different than oregano in chemistry. Oregano is typically rich in carvacrol while marjoram is dominated by sabinene hydrate and terpinen-4-ol. A recent study evaluated several Origanum oils–oregano (O. vulgare, O. hirtum) CT carvacrol, Syrian oregano CT sabinene hydrate/carvacrol, and marjoram–against respiratory pathogens (S. aureus, H. influenzae, H. parainfluenzae, P. aeruginosa). What the research found was that while each oil inhibited all the pathogens, marjoram was the most active oil against the tested pathogens.