Cool, minty, clearing. The terpene that opens the airways and clears the head.
Worth knowing
The primary compound in eucalyptus oil, in cough and respiratory medicines for over a century.
Did you know?
Eucalyptol is one of the few terpenes with real human clinical data. In trials, isolated cineole capsules (the same molecule, not inhaled cannabis) eased airway inflammation in asthma and reduced flare-ups in COPD and bronchitis. The respiratory reputation is earned; the cannabis dose is a separate question.
How it tends to land
Commonly reported as clear-headed and open. Tendencies, not promises. Your body writes the last word.
Pairs well with
Examined for these conditions
No condition has research pointing specifically to this terpene yet. Browse all conditions
Where the evidence stands
Ranked by how much each finding can actually tell you, strongest first. A trial in people outranks a study in cells, including when the answer is no.
Every trial below used 200 mg cineole capsules taken by mouth, three times a day: the isolated molecule, not inhaled or vaporized cannabis. That is 600 mg/day, far more than a terpene percentage on a label delivers. The evidence is real and it is about the molecule, not about a strain.
Pooled human trials
Most effective herbal treatment for acute post-viral rhinosinusitis
Pooling 47 randomised trials across 18 herbal treatments, cineole came out among the most effective for controlling acute post-viral rhinosinusitis symptoms, at GRADE moderate certainty. Pooled evidence like this outranks any single trial. Hoang MP, Seresirikachorn K, Chitsuthipakorn W, et al. (2023). Current Allergy and Asthma Reports, 23(2):93–109. PubMed 36609950
Human trial
Eased airway inflammation in asthma
Over 12 weeks, patients on cineole were able to cut their daily steroid dose by 36%, against 7% on placebo. Juergens UR, Dethlefsen U, Steinkamp G, et al. (2003). Respiratory Medicine, 97(3). PubMed 12645832
Human trial
Improved lung function and symptoms in asthma
In 247 patients over 6 months, significant improvement in lung function, asthma symptoms and quality of life. Worth H, Dethlefsen U. (2012). Journal of Asthma, 49(8). PubMed 22978309
Human trial
Reduced flare-ups in COPD
In 242 patients over 6 months, flare-ups were less frequent, less severe and shorter. Worth H, Schacher C, Dethlefsen U. (2009). Respiratory Research, 10:69. PubMed 19624838
Chemical identity, formula and molar mass: PubChem CID 2758, National Center for Biotechnology Information.
Terpenology is educational, not medical advice. Terpene effects are tendencies commonly reported by patients and early research, never guaranteed outcomes. Work with your certifying physician and pharmacist.