What is Zepbound?

TL;DR

Zepbound is a weekly injection that contains tirzepatide.
The average percent weight loss is 15% with 5-mg doses, 19.5% with 10-mg doses, and around 21% with 15-mg doses.
Zepbound may be associated with thyroid tumors in animal studies. It should be avoided in people with a personal or family history of thyroid cancer or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
Zepbound may reduce the absorption of oral medications and increase the risk of hypoglycemia when used with insulin or certain diabetes medications.

Managing weight isn’t just a cosmetic concern. It’s often a key part of controlling blood pressure or cholesterol levels and improving other health outcomes. However, diet and lifestyle changes aren’t always enough.

Medications that mimic the GLP-1 hormone can be effective for weight loss and related conditions such as diabetes. Zepbound is a newer weight-loss medication with a unique dual action compared with older GLP-1s.

Zepbound is a brand-name drug that contains the active ingredient tirzepatide. It’s administered as a subcutaneous injection (under the skin) once weekly and is used for weight loss in people who are overweight or obese.

Although results aren’t immediate, Zepbound has been shown to promote up to 21% average weight loss over 72 weeks. A doctor or healthcare provider prescribes it alongside a diet and exercise plan.

How Zepbound Works

Unlike similar medications like Wegovy (semaglutide) and Saxenda (liraglutide), the active ingredient of Zepbound works as a dual GIP/GLP-1 agonist.

In other words, it acts like two natural hormones involved in regulating appetite and blood sugar. These hormones are often released after a meal to stimulate insulin secretion, which facilitates the transport of glucose into the muscles for energy.

It also helps slow gastric emptying, the rate at which food and other substances move through the digestive tract. As a result, it can help individuals feel fuller and reduce caloric intake, thereby promoting weight loss.

Because it targets two hormones rather than a single one, as sole GLP-1 agonists do, it has a more potent effect. Zepbound is currently the only dual agonist for weight loss.

What is Zepbound Approved For?

Zepbound is approved by the U.S. Food and Drug Administration (FDA) for overweight and obesity when used alongside a diet and exercise plan. It’s also approved to treat moderate to severe obstructive sleep apnea (OSA) in adults who are obese.

A doctor or healthcare provider may prescribe Zepbound in adults who:

Are obese with a body mass index (BMI) of 30 or over
Are overweight with a BMI of 27 to under 30 with at least one weight-related health condition, such as high blood pressure, high cholesterol, or heart disease
Are obese and have OSA

Zepbound is not approved for type 2 diabetes. Instead, the active ingredient is found in another brand-name version called Mounjaro. Although Mounjaro contains tirzepatide, it’s typically used at a lower dosage for type 2 diabetes.

No version of tirzepatide is approved for people with type 1 diabetes or diabetic ketoacidosis. It’s also not approved for people with inflammation of the pancreas (pancreatitis).

Dosing & Titration of Zepbound

Zepbound has a specific dosing schedule that typically begins with a lower dose. The dosage is then gradually increased in 4-week intervals to reduce the risk and severity of side effects such as nausea and constipation.

The recommended starting dosage of Zepbound is 2.5 mg once weekly for 4 weeks. The dosage can then be increased by 2.5 mg after at least 4 weeks on the initial dose. For weight loss, the usual maintenance dosage is 5 mg, 10 mg, or 15 mg once weekly. For sleep apnea, the usual dose is 10-15 mg once weekly.

In many cases, the correct dosage will depend on how a person responds to the drug and how they tolerate it. For example, people who experience side effects may need to stick to a specific dose for longer, especially if they’re seeing some results.

A healthcare provider will recommend the most appropriate maintenance dose. According to the FDA label, the maximum dosage of Zepbound is 15 mg once weekly.

How Effective is Zepbound?

Those who’ve used Zepbound have achieved some of the most significant weight-loss outcomes of any FDA-approved medication to date. In clinical trials, many participants lost 15% to 21% of their body weight, with greater weight loss at higher doses. These results were found after taking the drug for more than a year.

Table: Zepbound Efficacy at a Glance

Trial Name	Population	Duration	Average Weight Loss Percentage
SURMOUNT-1	Adults with obesity or overweight with one or more weight-related conditions	72 weeks	Around 15% to 21%
SURMOUNT-2	Adults with obesity and type 2 diabetes	72 weeks	Around 13% to 15%
SURMOUNT-3	Adults with obesity after completing lifestyle changes	72 weeks	Around 21% to 23%
SURMOUNT-4	Adults with obesity who stopped versus continued tirzepatide	88 weeks	Maintained around 21% weight loss in those who continued treatment

Most people can achieve weight-loss outcomes comparable to those in clinical trials. However, real-world results can vary, with many people needing to continue treatment or follow strict lifestyle changes to manage their weight. In one observational study, adults taking tirzepatide for approximately 6 months experienced an average weight loss of roughly 13%.

Safety, Side Effects & Warnings

Although Zepbound is a proven and effective drug, it still comes with side effects like any other drug. The most common side effects of Zepbound include:

Nausea
Vomiting
Diarrhea
Constipation
Stomach pain
Indigestion
Burping
Heartburn
Fatigue

Since Zepbound is an injection, it’s not uncommon to see injection site reactions, such as itching, redness, or swelling around the area of injection. However, most side effects are mild and temporary.

Zepbound may cause serious side effects. Although rare, these may include:

Severe stomach problems
Kidney problems related to dehydration
Gallbladder problems
Pancreatitis
Low blood sugar (hypoglycemia)
Changes in vision
Mood changes

Allergic reactions are also possible in individuals who may be allergic to tirzepatide or other ingredients in Zepbound. Symptoms of an allergic reaction include rash, hives, difficulty breathing, and swelling of the face, tongue, or throat; such reactions often require immediate medical attention.

Zepbound isn’t recommended during pregnancy, as it may cause harm to an unborn baby. Women may want to stop Zepbound if they have plans to become pregnant. Otherwise, a non-oral birth control method is recommended during treatment.

For women who are breastfeeding, Zepbound isn’t known to be present in breast milk in large amounts. That’s because tirzepatide is a molecule that’s too large to be transported into breast milk. In addition, children who are nursing and ingest small amounts of tirzepatide usually break it down in their digestive tract, reducing the risk.

Drug Interactions of Zepbound

Zepbound can affect how the body absorbs other medications. Because it slows gastric emptying, it can reduce or delay the absorption of oral drugs. Your healthcare provider may need to change your medications or dosing if you take certain oral drugs, such as the following:

Oral hormonal contraceptives: Those using birth control pills will need to switch to a non-oral method, or add a barrier method, for 4 weeks after starting Zepbound and for 4 weeks after each dose increase.
Oral drugs that depend on absorption in the digestive tract: Medications that require consistent absorption, such as certain antibiotics, thyroid medications, and drugs with a narrow therapeutic index, such as warfarin, may require adjustment to maintain efficacy.

Zepbound can increase the risk of hypoglycemia when used with insulin or insulin-releasing medications, such as sulfonylureas like glipizide or glyburide. A healthcare provider may need to lower the dose of insulin or secretagogues to reduce this risk. People using these drugs together may need to watch for symptoms of low blood sugar, such as shaking, sweating, dizziness, or confusion.

It’s always essential to discuss prescription drugs, over-the-counter medicines, and herbal supplements being taken before starting treatment with Zepbound.

Zepbound vs. Wegovy: What’s the Difference?

Zepbound and Wegovy are both brand-name drugs approved for weight management. They’re subcutaneous injections administered once weekly alongside exercise and dietary changes. Although they’re used for similar purposes, they differ in key respects.

Approved Uses

Wegovy was approved in 2021 and is manufactured by Novo Nordisk, whereas Zepbound was approved in 2023 and is manufactured by Eli Lilly. Unlike Zepbound, which is approved for adults with obesity, overweight, or sleep apnea, Wegovy is approved for adults and children 12 and older with obesity. Wegovy is also approved to reduce the risk of certain events from heart disease, such as heart attacks and strokes, and a type of fatty liver disease called noncirrhotic metabolic dysfunction-associated steatohepatitis (MASH).

Active Ingredients

Both drugs contain different active ingredients: Wegovy contains semaglutide, a GLP-1 receptor agonist, and Zepbound contains tirzepatide, a dual GIP/GLP-1 receptor agonist. With its dual action, Zepbound has more potent effects on appetite reduction and may result in greater weight loss for many people.

Efficacy

One study compared tirzepatide with semaglutide and found that tirzepatide resulted in significantly greater weight loss than semaglutide. Those on tirzepatide were more likely to reach clinically meaningful weight loss (≥5%, ≥10%, ≥15%) and larger reductions at 3, 6, and 12 months than those on semaglutide. Tirzepatide also showed a greater overall decrease in weight and waist circumference at 72 weeks in adults with obesity.

Side Effects

Both medications commonly cause nausea, diarrhea, constipation, and stomach discomfort, especially during dose increases. Zepbound may cause more digestive symptoms than Wegovy, especially at higher doses. Although Wegovy may be easier to tolerate for some people, it’s possible to manage side effects with more gradual dose increases, eating smaller meals, and staying hydrated.

Dosing

Zepbound is available in 2.5 mg, 5 mg, and 15 mg pens, with a maximum weekly maintenance dose of 15 mg. Wegovy is available in 0.25 mg, 1.0 mg, and 2.4 mg weekly, with a maximum weekly dose of 2.4 mg. Both are available in prefilled auto-injector pens, which facilitate at-home administration.

Access, Cost, and Coverage of Zepbound

As a newer, brand-name drug, Zepbound comes with higher costs than other medications. Without insurance, the list price could be over $1,000 for a one-month supply. Although the exact cost can depend on the pharmacy and dose, there’s no question that Zepbound can be an expensive medication. Still, there may be ways to save.

For individuals with insurance, coverage varies. Some employer-sponsored plans may now cover GLP-1 medications for obesity, including Zepbound. However, many plans, including private and Medicare plans, may not provide comprehensive coverage. In addition, Medicaid coverage can vary by state. Nevertheless, insurance coverage may expand as GLP-1 drugs continue to demonstrate efficacy for conditions beyond weight loss.

Other Options to Save on Zepbound

Lilly Direct is a manufacturer program that caps the price of Zepbound vials for patients who don’t have or want to use insurance. The prices range from $299 to $449 per month, depending on the strength. The higher strengths may be restricted to following the prescription within 45 days of the last refill to keep the savings. Otherwise, the price could be higher.

Other savings options include prescription discount cards, patient assistance programs, and telehealth platforms. Compounded tirzepatide may also be an option for many patients. It contains the same active ingredient as Zepbound and should be effective when produced by a reputable pharmacy.

Lifestyle Habits and Other Tips for Taking Zepbound

Zepbound is most effective when used alongside consistent lifestyle habits. Eating smaller meals with a focus on protein and drinking enough fluids may help reduce nausea or other digestive side effects, especially during the first few months of starting the drug. Because Zepbound slows gastric emptying, dehydration can occur more easily; therefore, drinking water regularly and replacing fluids are key.

Other Tips for Taking Zepbound

Rotate injection sites each week (stomach area, thigh, or upper arm) to reduce irritation.
Take the dose on the same day every week.
Work with a healthcare provider to stay on a dose longer if nausea or constipation persists during dose changes.
Avoid injecting into areas that are bruised, tender, or swollen.
Contact a healthcare provider if persistent vomiting, signs of dehydration, or low blood sugar occur.
Keep the pen refrigerated until the first use, then store it at room temperature or as instructed by the drug label.
If a dose is missed, take it within 4 days (96 hours); otherwise, skip the missed dose and resume the regular schedule.

Taking Zepbound alone isn’t a solution. Other factors, such as lifestyle changes, proper use, and working with a healthcare provider, are essential for maximizing its benefits.

FAQs

How long does it take for Zepbound to start working?

Most people notice a reduced appetite within the first 1 to 2 weeks, but weight loss typically becomes more pronounced after 4 to 8 weeks, particularly with higher doses.

Do you gain weight back after stopping Zepbound?

Weight regain is common after stopping treatment, especially in those who don’t continue lifestyle changes. In studies, people who stopped tirzepatide regained more weight than those who stayed on their maintenance dose.

Can I drink alcohol while using Zepbound?

Alcohol can worsen nausea, dehydration, and low blood sugar. However, some providers allow moderate alcohol consumption, such as no more than two drinks per day for men or one drink per day for women.

Can Zepbound be taken long-term?

Yes, Zepbound may be used long-term to maintain weight loss and other metabolic benefits. Stopping the medication often leads to weight regain.

How does Zepbound help with sleep apnea?

Zepbound may help reduce the severity of symptoms in people with sleep apnea who are also obese. Because it helps reduce weight, Zepbound may help minimize airway obstruction.

Is Zepbound the same as Mounjaro?

Both medications contain tirzepatide, but they have different FDA approvals. Zepbound is approved for weight loss and sleep apnea, while Mounjaro is approved for type 2 diabetes.