Eucalyptus globulus is the most widely cultivated and commercially prevalent eucalyptus species, yielding an oil with among the highest 1,8-cineole content of any commercial eucalyptus — typically 60-85% — which underpins its sharp, penetrating medicinal aroma.^[1] Its essential oil is a well-established expectorant and antimicrobial agent, with a 2023 systematic review confirming antibacterial activity against MRSA across 20 studies.^[2] The high cineole concentration makes E. globulus more potent than most other species in the genus, though also more likely to be irritating to mucous membranes in undiluted form.