CBD and tinnitus: no human trial has ever been completed
No clinical trial has ever tested CBD for tinnitus in humans. The only registered cannabis trial for this condition, opened in Israel in 2013, was withdrawn before a single participant enrolled. In the two published rat experiments, cannabinoids did not reduce tinnitus and sometimes increased it. France's Inserm puts the share of adults with tinnitus at about 10% and states that no curative treatment exists.
Key takeaways
- Among 11,427 adults surveyed in 12 European countries, 14.7% had tinnitus and 1.2% a severe form.
- Rats given cannabinoids showed more tinnitus-related behaviour in two New Zealand experiments, in 2010 and 2015.
- The 2015 experiment used THC and CBD together, and no tinnitus model has ever tested CBD on its own.
- Inserm describes two approaches: a hearing aid when hearing loss is present, and cognitive behavioural therapy.
Tinnitus: definition and figures
Tinnitus is a whistling, buzzing or ringing that you hear although no outside source produces it. The Inserm file estimates that it may affect about 10% of adults, with highly disabling forms making up less than 1% of cases. To date, Inserm adds, no curative treatment exists.
In 2022, The Lancet Regional Health Europe published a harmonised European survey that asked 11,427 adults in 12 countries, France among them, the same questions. Tinnitus affected 14.7% of them, and 1.2% had a severe form. The rate varied widely from one country to another, from 8.7% in Ireland to 28.3% in Bulgaria, and rose with age and with hearing loss.
When a common symptom has no curative treatment, every possible lead gets explored. For cannabinoids, there is a genuine biological argument, and it deserves to be followed to its end.
Why the endocannabinoid system comes up
Signals from the inner ear pass through the cochlear nucleus, a relay in the brainstem. A team at the University of Otago, New Zealand, showed in Hearing Research in 2007 that, in rats, many of its neurons carry CB1 receptors. Salicylate injections, which cause tinnitus in the animal, reduced the number of CB1-carrying neurons in the ventral part of the nucleus, while the dorsal part showed no clear change.
So the endocannabinoid system is present along the auditory pathway. A receptor's presence in a structure, though, cannot tell you whether a molecule that binds to it improves the symptom. Many articles go no further, yet the same team did run the next experiment.
In rats: two experiments, no benefit
In a 2010 paper, also in Hearing Research, the researchers gave rats treated with salicylate two synthetic cannabinoids, WIN55,212-2 and CP55,940. Tinnitus-related behaviour did not decrease with either. It actually increased at 3 mg per kilo of the first and 0.3 mg per kilo of the second.
In 2015, the team moved to an acoustic trauma model, which is closer to real hearing damage. For 27 days, the rats received 1.5 mg per kilo of Δ⁹-THC and 1.5 mg per kilo of CBD daily, a 1 to 1 ratio. The title of the paper in Frontiers in Neurology states the result: "Cannabinoid CB1 Receptor Agonists Do Not Decrease, but may Increase Acoustic Trauma-Induced Tinnitus in Rats". In the noise-exposed group, more animals had tinnitus with cannabinoids, while the controls showed no such rise. According to the authors, cannabinoids may promote tinnitus when hearing is already damaged.
Because the protocol combined THC and CBD, the result cannot be attributed to CBD, which no tinnitus model has ever tested alone. That gap in the data says nothing in CBD's favour. The two lead authors reviewed the field in Current Opinion in Neurology in 2019. In their reading, all the available animal data show that CB1 agonists either leave tinnitus unchanged or make it worse. They consider the use of cannabinoids for tinnitus premature and unsupported by evidence.
In humans: one registered trial, withdrawn
Only one trial on cannabis and tinnitus appears in the ClinicalTrials.gov registry. The Wolfson Medical Center in Israel opened it in 2013 to compare cannabis capsules with placebo over one month. Its record now reads "withdrawn", with zero participants enrolled. Nobody has registered a trial on CBD alone.
Patients want it all the same. In a survey published in 2023 in the Journal of Otolaryngology - Head & Neck Surgery, 45 patients at a specialist clinic in Canada answered questions on the subject. Of these, 96% would consider cannabis for their tinnitus, 36% had already used it and 22% were using it at the time. Such a survey records expectations and cannot show an effect.
Small samples and missing placebo groups limit much of this research, as our review of what clinical studies on CBD really say explains. For the related question of headaches, see CBD and migraine.
What Inserm describes as care
Care today seeks to reduce the distress that tinnitus causes. When hearing loss accompanies it, Inserm says a hearing aid most often improves hearing. Cognitive behavioural therapy has proved effective in several studies. Sound therapies show moderate efficacy and are not necessarily better than other approaches.
Everything starts with an assessment, first by the GP, then by an ear, nose and throat (ENT) specialist with an audiogram. See a doctor promptly if tinnitus appears suddenly, affects one ear only, beats in time with your pulse or comes with hearing loss.
What French rules say
No CBD product sold in France may claim an effect on tinnitus, or on any disease. A product presented as acting on a disease meets the definition of a medicine, and a medicine needs an authorisation. Epidyolex, the only authorised CBD-based medicine, is prescribed for rare epilepsies.
The 2015 mixture contained THC, which full-spectrum products also carry in trace amounts. Data on documented side effects and drug interactions are gathered on our page about CBD side effects, and the laboratory page explains how to find the Δ⁹-THC level on a certificate of analysis.
Frequently asked questions
No evidence supports it. CBD has never been tested for tinnitus in a human trial, and cannabinoids brought no improvement in the rat experiments.
Two rat experiments found more tinnitus-related behaviour with cannabinoids: synthetic molecules in 2010, a mixture of THC and CBD in 2015. The part played by CBD alone has not been isolated, and these results cannot be transferred to humans.
Tinnitus changes with attention, tiredness and stress, so the placebo effect has a strong hold on it. People who were disappointed also post less often. Only placebo-controlled trials could settle the question, and none exist.
No. The ClinicalTrials.gov registry has a single cannabis trial for this condition, withdrawn before anyone enrolled, and none on CBD alone.
Start with your GP, who will send you to an ENT specialist for a hearing assessment. Hearing loss often goes with tinnitus, and when it does, the care is different.
Written by the Phytogrammes team
Each journal article draws on cited primary sources: ANSM, EFSA, EUR-Lex and peer-reviewed publications. Product profiles are distinguished from documented laboratory results. Our approach.
Article published on . CBD is not a medicine.