Ivermectin and Tinnitus: What Is Known

Tinnitus is not a recognized side effect of ivermectin when it is taken as prescribed. Standard patient drug information lists dizziness, nausea and stomach upset among its possible effects, but not ringing in the ears. Some reports have described ear and balance problems after ivermectin use, often when people took high doses or products made for animals, and a lab study found damage to hearing-type cells in fish, but there's no solid evidence that a normal course causes lasting tinnitus.

If your ears started ringing after taking it, the details of what you took, and how much, matter a great deal.

What ivermectin is and how it's used

Ivermectin is an antiparasitic medicine. In the US, ivermectin tablets are prescribed for certain parasitic worm infections, such as strongyloidiasis and onchocerciasis (river blindness). Topical forms are used for head lice and for rosacea. These uses are short-term or applied to the skin, and when taken as directed, the medicine is generally considered well tolerated.

During the COVID-19 pandemic, ivermectin became widely discussed as a possible treatment. Large clinical trials did not show that it helped, and US health agencies advised against using it for COVID-19 outside of research. During that period, some people took it in higher amounts, for longer, or in forms made for livestock. That is where most worries about side effects, including ear and balance symptoms, come from.

Possible side effects to know about

According to MedlinePlus, side effects of ivermectin tablets can include:

• Dizziness
• Nausea, vomiting, diarrhea or constipation
• Stomach pain or bloating, and loss of appetite
• Weakness or shaking of part of the body
• For people treated for river blindness, reactions such as swelling, joint pain, fever, rapid heartbeat, eye symptoms, and dizziness or fainting when standing up

More serious effects that need urgent care include a blistering or peeling rash, severe sleepiness, confusion and, rarely, coma. Ringing in the ears is not on the list.

Why dizziness matters here

People sometimes describe dizziness, unsteadiness and ear sensations together, because the inner ear handles both hearing and balance. If you felt dizzy and noticed ringing at the same time, both are worth reporting. Your doctor will want to know whether the room was spinning (vertigo), you felt faint, or you felt off-balance, because each points in a different direction.

Prescribed doses versus high or animal doses

The risk picture changes sharply depending on how ivermectin is used. This table summarizes the general differences.

What the research says

The research on ivermectin and the ear is limited and comes from a few different kinds of evidence:

• Drug information: Standard patient information lists dizziness but not tinnitus. Medicine labels are built from clinical trials and reports over many years, so a missing side effect isn't proof it never happens, but it suggests it isn't common at normal doses.
• Reviews of COVID-era medicines: A 2021 review of medicines proposed for COVID-19 listed ivermectin among drugs with reported effects on hearing or balance. These reports are mostly individual cases and can't show how often such effects happen or prove the drug was the cause.
• Lab and animal studies: A 2022 study found that ivermectin damaged hair cells (the sensory cells similar to those in the inner ear) in zebrafish. In the same study, rats given a dose comparable to human treatment for 10 days showed no hearing loss and no loss of inner ear hair cells. Fish findings don't translate directly to people.
• Overdose reports: Poison centers have documented ivermectin overdoses, especially from animal products, with symptoms such as dizziness, confusion, vision changes and, in severe cases, seizures and coma. Ear ringing in that setting is possible but is far from the main concern.

The National Institute on Deafness and Other Communication Disorders (NIDCD) notes that a number of medicines can cause tinnitus as a side effect. Ivermectin is not one of the classic examples, which usually include high-dose aspirin, certain antibiotics, some cancer medicines and some diuretics.

Other explanations worth considering

If you notice ringing after a course of ivermectin, it's worth thinking about what else was happening at the same time:

• The illness itself. Viral infections, including COVID-19, have been linked to new or worsened tinnitus in some people. A fever or ear congestion can also change how you hear.
• Other medicines taken together. Pain relievers such as high-dose aspirin, some antibiotics and other drugs can affect the ears.
• Stress and poor sleep. Both make existing tinnitus much more noticeable.
• Earwax or ear infection. A blocked or inflamed ear can bring on ringing and muffled hearing.
• Coincidence. Tinnitus is common and can appear for reasons unrelated to any new medicine.

Sorting these out is a job for your doctor and, if needed, an audiologist, but bringing a clear timeline helps a lot. A simple way to build one is to list the dates you got sick, started and finished ivermectin, took any other medicines, and first noticed the ringing. Add whether the sound is steady or pulsing, which ear it's in, and whether your hearing seems muffled. That one page can save time at the appointment and helps your doctor see whether the timing really points to the medicine or to something else.

Using ivermectin safely when it's prescribed

If a doctor prescribes ivermectin for a parasitic infection, a few habits help you get the benefit with the least risk to your ears and the rest of your body:

• Take it exactly as directed. The dose is usually based on body weight, and many courses are a single dose or a short series. More is not better.
• Follow the food directions on your label. Ivermectin tablets are commonly taken on an empty stomach with water; ask your pharmacist if you're unsure.
• Share your full medicine list, including supplements. Some medicines can change how the body handles ivermectin, and others, such as sedatives, may add to drowsiness or dizziness.
• Stand up slowly after taking it, especially if you're being treated for river blindness, since dizziness or lightheadedness on standing can happen.
• Keep a short symptom note for a few days, including any ringing, muffled hearing or unsteadiness, and report anything new.

How long might ear symptoms last?

There isn't good research on how long ear symptoms last after ivermectin, because so few cases have been studied in detail. With many medicines, side effects that come from the drug fade as it clears from the body. Ivermectin is usually taken briefly, so if it were responsible, you might expect symptoms to ease over days to weeks. That's a general expectation, not a promise. Any ringing that lasts, gets worse, or comes with hearing loss should be checked with a hearing test, and sudden hearing loss is an urgent problem that needs care within a day or two.

Your next steps

1. Write down exactly what you took: the product, strength, how much, how often, and where it came from, plus any other medicines or supplements taken at the same time.
2. Talk to your prescriber or pharmacist about the ringing. If you're still on a prescribed course, don't stop or change it without asking them first.
3. Use only human ivermectin from a pharmacy, prescribed for an approved use, and never products made for animals.
4. Get a hearing test if the ringing lasts more than a couple of weeks or comes with any change in hearing.
5. Ease the sound meanwhile with soft background sound at night, ear protection around loud noise, and a simple daily note of how loud the ringing seems.