Tepezza: Side Effects, FDA Warnings and Hearing Loss Risks

Tepezza, also known by its generic name teprotumumab, is a prescription medication approved by the U.S. Food and Drug Administration (FDA) in 2020 to treat thyroid eye disease (TED).

Tepezza is the first and only drug approved in the U.S. specifically for TED. The American pharmaceutical company Amgen currently manufactures Tepezza following its 2023 acquisition of the drug’s original manufacturer, Horizon Therapeutics.

TED, also known as Graves’ eye disease or Graves’ orbitopathy, is a rare condition that causes the immune system to attack tissues around and behind the eyes. This causes inflammation, swelling, eye bulging (proptosis), double vision (diplopia), pain, redness and, in severe cases, vision loss.

Patients treated with Tepezza receive an initial Tepezza intravenous (IV) infusion and then have another infusion every three weeks for a total of eight. Each infusion lasts about 60 to 90 minutes.

How Tepezza Works

Tepezza treats TED by targeting the source of inflammation and swelling.

Tepezza inhibits a cell receptor called insulin-like growth factor-1 receptor (IGF1R) that regulates cell growth. Inhibiting this protein helps reduce eye bulging, discomfort and vision problems caused by swelling and inflammation.

Common Tepezza side effects, including muscle spasms, nausea and diarrhea, typically last a few days to weeks. However, if these side effects bother you or don’t go away, you should talk to your doctor.

We’ve listed common side effects from most common to least common. Side effect percentages are based on 84 clinical trial participants who took Tepezza.

More serious Tepezza side effects include hearing loss, infusion reactions and irritable bowel disease (IBD) flare-ups. Talk to your doctor right away if you experience any of these side effects.

When the FDA first approved Tepezza in 2020, the drug’s label didn’t have warnings for permanent hearing loss. Horizon first added warnings about permanent hearing problems in July 2023.

Tepezza may cause hearing loss. For some people, this can be permanent. The FDA required a label change to warn of hearing loss in 2023.

In the first clinical trials, Horizon reported that 10% of clinical trial participants experienced hearing problems. In a more recent clinical trial, Horizon reported that the number went up to 20%.

However, some real-world studies say that the number is around 46%. One small study presented at ENDO 2021 found 13 out of 28 patients who took Tepezza complained of hearing problems, and three of those patients still had problems after treatment had finished.

How Does Tepezza Cause Hearing Loss?

Scientists think Tepezza may cause hearing loss because it inhibits IGF1R activity.

IGF-1 protects ear hair cells from noise and toxicity. Because Tepezza blocks IGF-1, the ear hairs are less protected from damage, leading to hearing loss.

Hearing Loss Symptoms To Look Out For

In studies, people who took Tepezza began experiencing hearing loss symptoms after receiving around four infusions.

The onset of hearing loss symptoms is gradual. One 2025 study in Otology and Neurotology showed that half of Tepezza patients reported hearing loss, but 75% of those patients didn’t start losing their hearing until the sixth infusion.

According to post-marketing data on the FDA Adverse Event Reporting System (FAERS), there have been 4,937 Tepezza adverse event reports as of November 2025. Of those, 958 reports included some form of hearing loss, while 533 reported tinnitus.

Work with your medical provider to monitor your blood work and hearing health while taking Tepezza. Keep records of your health before, during and after taking Tepezza and report any hearing changes right away.

Because of the risk of hearing loss and other serious side effects, authors of a 2025 study published in Frontiers in Endocrinology suggested patients undergo hearing testing prior to taking Tepezza.

They also suggested monitoring patients taking Tepezza for hearing loss, monitoring blood glucose levels and assessing IBD risk.

If you experience any serious Tepezza side effects, talk to your medical provider or seek emergency medical care right away.

Tepezza received FDA approval in 2020, but didn’t include a warning for potentially permanent hearing loss until 2023. Due to this delayed warning, hundreds of people have filed Tepezza lawsuits against its manufacturers.

As of November 2025, 291 Tepezza hearing loss lawsuits were pending in a multi-district litigation (MDL) in the Northern District of Illinois. In an MDL, federal courts consolidate multiple cases with similar claims into a single litigation to speed up the legal system.

Lawsuits allege that the company didn’t adequately warn patients about the risk of permanent hearing loss. The company also allegedly downplayed the frequency of hearing complications and didn’t recommend hearing testing.

The FDA has updated Tepezza’s packaging with safety information and warnings several times. The first update added information on fetal harm, infusion reactions, high blood sugar and worsening existing IBD symptoms.

Next, the agency required additional information about hyperglycemia. Specifically, prescribing information now includes instructions to check patients for elevated blood glucose levels before and during treatment.

In July 2023, the manufacturer added a warning about hearing loss. The update urges health care providers to counsel patients about this risk.

These are standard warnings included on Tepezza’s label. The FDA currently requires no black box warnings, the agency’s most serious medication alerts, for Tepezza adverse effects.