Zepbound (tirzepatide) is FDA-approved for two conditions: chronic weight management in adults and moderate to severe obstructive sleep apnea in adults with obesity. It is a once-weekly injection made by Eli Lilly, and both approvals require that patients also follow a reduced-calorie diet and increase physical activity.
Chronic Weight Management
The FDA first approved Zepbound in November 2023 for chronic weight management in adults. You qualify for a prescription if you have a BMI of 30 or greater (classified as obesity) or a BMI of 27 or greater (classified as overweight) with at least one weight-related condition such as high blood pressure, type 2 diabetes, or high cholesterol.
This is not a short-term diet drug. The “chronic” label means Zepbound is intended for ongoing use alongside lifestyle changes. Stopping the medication typically leads to weight regain, which is consistent with how the body responds to other weight management medications in this class.
Obstructive Sleep Apnea
In early 2025, the FDA approved Zepbound as the first medication for moderate to severe obstructive sleep apnea (OSA) in adults with obesity. This was a significant expansion because OSA has historically been treated with devices like CPAP machines rather than medication.
The approval was based on two studies of 469 adults without type 2 diabetes, followed over 52 weeks. One study included participants already using positive airway pressure therapy, while the other enrolled people who were unable or unwilling to use it. In both groups, those taking Zepbound experienced meaningful reductions in the number of times their breathing paused or became shallow during sleep. Greater proportions of treated participants also achieved remission or mild OSA with resolution of symptoms compared to placebo.
How Zepbound Works
Zepbound activates two hormone receptors involved in appetite and metabolism: GIP and GLP-1. Most other medications in this category, like semaglutide, only target one of those receptors. By engaging both, Zepbound influences blood sugar regulation, slows stomach emptying, and reduces hunger signals through complementary pathways.
What makes the dual mechanism interesting is how it interacts with each receptor differently. At the GIP receptor, it behaves much like the body’s own GIP hormone. At the GLP-1 receptor, it activates the signaling pathway in a way that causes less receptor “burnout” over time compared to the natural hormone. In head-to-head clinical trials against the highest approved dose of semaglutide, all three doses of tirzepatide produced greater reductions in both weight and blood sugar.
Zepbound vs. Mounjaro
One common point of confusion: Zepbound and Mounjaro are the same molecule (tirzepatide) made by the same company. The difference is entirely regulatory. Mounjaro is FDA-approved for type 2 diabetes. Zepbound is approved for weight management and obstructive sleep apnea. They are identical medications at the molecular level, but Eli Lilly markets them under separate brand names so each can have its own FDA labeling, insurance coverage pathway, and prescribing guidance. Your doctor will prescribe one or the other depending on which condition is being treated, and insurance coverage often differs between them.
Dosing Schedule
Zepbound is a subcutaneous injection you give yourself once a week. Everyone starts at 2.5 mg weekly for the first four weeks, which is a tolerability dose rather than a therapeutic one. After that, the dose increases to 5 mg. From there, your doctor can raise it in 2.5 mg increments every four weeks or longer, up to a maximum of 15 mg per week. This gradual approach helps your body adjust and reduces the likelihood of side effects, particularly nausea.
Who Should Not Take It
Zepbound carries a boxed warning, the FDA’s most serious label, related to thyroid cancer. In animal studies, tirzepatide caused thyroid tumors. It is contraindicated if you have a personal or family history of medullary thyroid carcinoma or a condition called Multiple Endocrine Neoplasia syndrome type 2. These are rare but serious considerations your prescriber will screen for.
Zepbound is currently approved for adults only. There is no FDA approval for use in adolescents or children for any indication.
What Zepbound Is Not Approved For
Despite containing the same active ingredient as Mounjaro, Zepbound does not carry an FDA approval for type 2 diabetes. It is also not approved for cosmetic weight loss in people who fall below the BMI thresholds, for heart disease risk reduction, or for any pediatric use. Prescribers can technically use medications off-label, but insurance coverage generally follows the approved indications closely, and for a medication in this price range, that distinction matters.