Now I have a constant loud hiss in my ears that has been driving me nuts. Do NOT put tea tree oil (or any other essential oil) in your ears, unless you’d like to go deaf an a slow annoying way. I was using super concentrated pharmaceutical grade 100% tea tree oil, by the way. Here’s the study I should have read before I did this:
A study of tea tree oil ototoxicity.
AuthorsZhang SY, et al. Show all Journal
Audiol Neurootol. 2000 Mar-Apr;5(2):64-8.
Auditory Laboratory, Department of Physiology, University of Western Australia, Nedlands, Australia.
Tea tree oil shows promise as an effective treatment for a number of micro-organisms commonly associated with otitis externa and otitis media, but its possible ototoxicity has not been previously assessed. The ototoxicity of tea tree oil was examined in the guinea pig by measuring the thresholds of the compound auditory nerve action potential (CAP) to tone bursts before and after instillation of the oil into the middle ear. After 30 min of instillation, 100% tea tree oil caused a partial CAP threshold elevation at 20 kHz. A lower concentration of oil [2% tea tree oil dissolved in saline using 0.5% detergent (Tween-80)] did not cause any significant lasting threshold change after middle ear instillation for the same period of time. The latter concentration of oil is greater than the minimum inhibitory concentration reported for most micro-organisms in the effective spectrum of the oil and this suggests that this concentration may be safe and effective provided only short exposures (about 30 min) are used. The results suggest that high concentrations of tea tree oil applied to the round window for a relatively short time are to some extent ototoxic to the high-frequency region of the cochlea. Hence further study is needed to establish whether tea tree oil can be used with safety in the treatment of external and middle ear infections. … NIH.gov
It’s so loud! I had this years ago 2009 and it went away, so I’m hopeful that some of the nerve damage will repair over time.
Poison Control said they had no reports of hearing loss from tea tree oil.
UPDATE: Looking back closer at the recordings of my life events, the guilt of Tea Tree oil is not so clear.
My first note about the ringing hiss in my ears was actually Thursday, Nov 22nd 9:10 AM. I’d had only 4.5 hours sleep. I had stayed up until 4:30 AM working on my music in my home recording studio. I probably damaged my hearing with many hours of constant loud music. … Or some 100% tea tree oil got to some nerves in my ears and killed them… Or both.
10:30 pm Sunday 12.2.12: Still having the loud hiss in both ears, more in the right ear.
Never eat tea tree oil!
The Mayo Clinic states that when ingested, tea tree oil may cause abdominal pain, diarrhea, confusion, drowsiness, lethargy, uncoordinated walking, depressed immune function and coma. While the Mayo Clinic cites some evidence that tea tree oil used as a mouthwash may alleviate symptoms of gingivitis or thrush, a yeast infection of the mouth, it cautions that swallowing any amount of tea tree oil is toxic. Exercise discretion when using any mouthwash containing tea tree oil to avoid oral toxicity. The American Cancer Society cautions that tea tree oil preparations should not be used in children or if you are a woman who is pregnant or breastfeeding.