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5 min read

Zepbound for Weight Loss: How it Works

Published on January 8, 2024
5 min read
Medically reviewed by
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A complete guide to Zepbound, a brand new weight loss drug

The FDA’s November 2023 approval of Zepbound will give millions of Americans access to a highly effective weight loss aid. Unlike other buzzy drugs currently gaining notice for their weight loss effects, Zepbound is a new weight loss drug specifically designed and FDA-approved to treat obesity in adults. This article will detail how Zepbound works, what to consider before taking it, and who it may be right for.

What is Zepbound?

Zepbound is a prescription medication made by Eli Lilly and Company. It contains the active ingredient tirzepatide, also in Eli Lilly’s Mounjaro—a type 2 diabetes drug.

Zepbound was officially approved by the U.S. Food and Drug Administration (FDA) in November 2023 for chronic weight management. It is used in adult patients with obesity or overweight with weight-related medical health conditions. This approval makes it one of the few drugs on the market officially designated for weight management.

Tirzepatide is Zepbound’s active ingredient. It belongs to a novel class of drugs called dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists.

The dual action of tirzepatide affects blood sugar and food intake in multiple ways, including:

  • Prompting the pancreas to release insulin when blood sugar levels are high (known as the glucose-dependent insulin response)
  • Decreasing the release of glucagon, which aids in lowering blood sugar levels
  • Slowing the process of stomach emptying, aiding in appetite control, and reducing food consumption
  • Encouraging a feeling of fullness following meals

Zepbound is given to patients as a subcutaneous injection delivered just under the skin once a week. It is supplied as a prefilled pen with a thin needle at one end.

How does Zepbound cause weight loss?

Tirzepatide belongs to a novel class of drugs called dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists. Tirzepatide is so novel it is the only drug of its kind. In lower doses, it regulates blood sugar levels and manages body weight in patients with type 2 diabetes. Zepbound contains a higher dose of tirzepatide, which effectively affects weight loss. It does this through replicating both GIP and GLP-1.

GLP-1

GLP-1 receptor agonists emulate the actions of a natural hormone known as GLP-1. After a meal, the body releases GLP-1, prompting the pancreas to increase insulin production. GLP-1 ensures that insulin is released appropriately, particularly following a meal when blood sugar levels rise. A spike in blood sugar can result in cravings for sugary carbohydrates or high-calorie foods. Regulating blood sugar can help curb the urge to indulge in unhealthy foods after a meal.

GLP-1 has several other beneficial effects. It inhibits the release of another hormone called glucagon, which originates from the pancreas. Unlike insulin, glucagon raises blood sugar levels by instructing the liver to release stored sugar into the bloodstream. By blocking glucagon's action, GLP-1 helps prevent excessive sugar release from the liver, which can lead to elevated blood sugar levels.

GLP-1 also slows down the emptying of the stomach, causing it to take more time to transfer food into the small intestine. This leads to a gradual release of nutrients from the meal into the body and a prolonged feeling of fullness after eating.

Additionally, GLP-1 may influence the brain, leading to increased feelings of satisfaction and reduced hunger. When GLP-1 is released following a meal, it signals to the brain that the stomach is full, reducing the desire to eat more. This, in turn, helps curb appetite.

The combination of stabilized blood sugar levels and reduced appetite has been shown to support weight loss in patients when combined with a reduced-calorie diet and increased physical activity.

GIP

The glucose-dependent insulinotropic polypeptide (GIP) is a hormone the gut releases in response to food consumption. Its primary role is to regulate blood sugar levels in response to the specific nutrients in your meal, particularly carbohydrates and fats.

This hormone signals the pancreas to release insulin, which facilitates the absorption and utilization of sugar from the ingested food by your cells. Additionally, it prevents the liver from overproducing sugar.

While the precise impact of GIP on weight loss is still under investigation, its role in stimulating insulin release and improving glucose uptake may indirectly support weight management by assisting in blood sugar regulation. Stable blood sugar levels can help reduce cravings for sugary and high-calorie foods.

It is important to note that Zepbound will not be used as a standalone treatment for obesity or excess body weight. It is most effective when paired with regular exercise and a reduced-calorie diet. Patients who take Zepbound without adhering to the prescribed lifestyle changes may not lose weight.

Are there other benefits to taking Zepbound?

Zepbound is FDA-approved for chronic weight management in adults. It is not indicated for the treatment of any other condition. Treating obesity, however, can result in improved cardiovascular health. Treatment can also reduce the risk of serious cardiovascular events like a heart attack or stroke.

Obesity and heart problems are closely linked. Excess body weight significantly increases the risk of cardiovascular issues. When a person is obese, there is an accumulation of fat tissue, particularly around the abdomen. This buildup can lead to high blood pressure, high cholesterol levels, and insulin resistance. These issues, combined with chronic inflammation associated with obesity, put added strain on the heart and blood vessels. Over time, this can lead to the development of conditions such as heart disease, heart attacks, and heart failure.

Obesity medications such as Zepbound can reduce the risk of these complications by helping patients achieve and maintain a healthy body weight. The use of Zepbound should be coupled with regular exercise and a healthy diet as a part of a comprehensive weight loss strategy.

Does Zepbound cause side effects?

The FDA officially approved Zepbound in November 2023 as a treatment for obesity. The approval was based on data from phase 3 clinical trials SURMOUNT-1 and SURMOUNT-2. In these trials, adults with obesity experienced significant weight loss when taking Zepbound in combination with diet and exercise. The highest dose resulted in an average weight loss of 48 pounds, while the lowest dose led to an average loss of 34 pounds, compared to only 7 pounds in the placebo group. Moreover, 1 in 3 patients on the highest dose lost over 58 pounds.

While Zepbound is safe and effective for most adults, it has been shown to cause side effects in some patients.

The most common side effects of Zepbound include:

  • Upset stomach
  • Gas
  • Constipation
  • Diarrhea
  • Loss of appetite
  • Injection site reactions
  • Fatigue

More severe side effects include:

  • Severe stomach pain
  • Allergic reactions such as hives, skin rash, swelling, or difficulty breathing
  • Vomiting
  • Changes in heartbeat
  • Fever
  • Heartburn

If you experience any side effects while taking Zepbound, immediately seek medical attention from a licensed healthcare provider.

What should I tell my doctor before I take Zepbound?

Before starting treatment with any prescription medication, you should tell your doctor about any medical conditions you have, any medications or supplements you are taking, and any allergies you may have. This information will help reduce the risk of any possible interactions or adverse reactions to Zepbound.

Your healthcare provider may avoid prescribing Zepbound if you have the following:

  • Pancreatitis or gallbladder disease
  • Thyroid problems
  • Thyroid tumors
  • Multiple endocrine neoplasia syndrome type 2 (MEN2)
  • Kidney problems
  • Stomach or intestinal problems (such as gastroparesis)
  • Allergies to tirzepatide
  • Diabetic retinopathy

Zepbound may not be prescribed to pregnant women, women who are trying to conceive, or women who are breastfeeding.

Who is eligible for a Zepbound prescription?

Eligibility for the weight loss drug Zepbound is at the prescribing healthcare provider's discretion. Zepbound is approved as a treatment for obesity in adults. It is specifically indicated for use in adults with obesity (with a body mass index— BMI—of 30 kg/m2 or greater) or overweight adults (a BMI of 27 kg/m2 or greater) who also have weight-related medical problems such as high blood pressure, heart disease, or obstructive sleep apnea.

The list price of Zepbound is about $1,000. You may be eligible for discounts through your insurance coverage. Talk to your provider and insurance company about the cost of Zepbound and any discounts you may qualify for.

What is the storage and dosage information for Zepbound?

Zepbound is given through a subcutaneous injection via a prefilled injection pen. The typical starting dose is 2.5 mg. Patients will take this preliminary dosage for 4 weeks before increasing it to 5 mg. If needed, your provider will increase the dose in 2.5 mg increments until the maintenance dose is reached. Maintenance doses of Zepbound are 5 mg, 10 mg, or 15 mg, depending on the medication’s efficacy and your tolerance to it.

Zepbound should be stored as directed by your healthcare provider or according to the medication's packaging instructions. Follow the recommended storage conditions, keeping the medication in the refrigerator between 36-46℉.

Do not freeze Zepbound or use Zepbound if the medication is frozen.

What’s the difference between Zepbound and Wegovy?

Zepbound and Wegovy are both FDA-approved for the treatment of obesity. These drugs work similarly, with some minor differences between them.

Wegovy is made by Novo Nordisk. It contains the active ingredient semaglutide, the primary actor in Ozempic—a medication approved for treating type 2 diabetes. Semaglutide is a GLP-1 receptor agonist that regulates blood sugar and curbs appetite.

As of now, there are no peer-reviewed studies directly comparing Wegovy and Zepbound. However, in specific clinical trials, tirzepatide affected more significant weight loss than semaglutide. Patients who took semaglutide for weight loss lost about 15% of their body weight, while those taking Zepbound lost about 26.7%.

This difference in results may be attributed to Zepbound’s action replicating GLP-1 and GIP, while Wegovy and Ozempic only mimic the action of GLP-1. Taking Zepbound with other GLP-1 agonists is not recommended.

In addition to the difference in efficacy, Zepbound may be cheaper than Wegovy. The list price for Wegovy is between $1,300 and $1,500 per month. The list price of Zepbound is just over $1,000 per month. The prices may vary depending on your insurance coverage.

How do I get a prescription for Zepbound?

Zepbound is a prescription drug, meaning that you must have a written order from a licensed healthcare provider to get it. It cannot be purchased over the counter.

Zepbound is available under its brand name. There are no generic versions of Zepbound currently available.

Weight loss drugs are prescribed to individuals with obesity or individuals who are overweight and managing a weight-related health condition. If you are curious about Zepbound or any other weight loss drug, talk to your healthcare provider these treatment options You should also discuss the cost, potential side effects, and any concerns you may have.

How can Sesame help me get a prescription for Zepbound?

Sesame offers a comprehensive online weight loss program to help you get started on your weight loss journey.

Sesame’s online weight loss program is a subscription which renews every 3 months and includes a video consultation with a weight loss doctor or specialist, a GLP-1 prescription (if appropriate), insurance coordination for medication coverage, and 90 days of unlimited messaging with your provider.

Note that all prescriptions are at the discretion of your healthcare provider.