Drug development in the realm of weight loss has taken off in recent years with approvals like liraglutide (Saxenda) and semaglutide (Wegovy). These options offer new hope for patients struggling with weight, causing these drugs to make a big impact both in the medical community and at large in the media. These approvals have built momentum in the weight loss world, with a new drug hitting the market in recent months.

This new drug is known as Zepbound, a medication meant for both type 2 diabetes and weight loss. Two large-scale trials have confirmed its robust efficacy in helping individuals shed pounds, leading to its approval just this past November. This article will discuss exactly how Zepbound works and functions for weight loss.

What is Zepbound?

Just this past month, Zepbound, also known as tirzepatide, was approved by the United States Food and Drug Administration (FDA). It is indicated for weight loss management in adults who are obese (defined as a body mass index [BMI] of 30 kg/m2 or more) or overweight (defined as a BMI of 27 kg/m2 or more) with a minimum of one weight-associated condition. Such conditions could include things like high cholesterol, high blood pressure, or type 2 diabetes. Zepbound is meant to be used as an adjunct to diet and exercise.

What is Zepbound used for?

As aforementioned, Zepbound is used to help obese or overweight individuals lose weight. As many as 70 percent of adults in the US are considered overweight or obese, and a large number of these individuals have a weight-associated disease as a result. People with excess weight are at increased risk of numerous conditions, including but not limited to:

  • High blood pressure
  • Type 2 diabetes
  • Coronary heart disease
  • High cholesterol
  • High triglycerides
  • Stroke
  • Sleep apnea
  • Cancer
  • Gallbladder disease
  • Pain

Many of these conditions associated with being overweight and obese can lead to death, including potentially fatal conditions like stroke, diabetes, and heart disease. Likewise, the obesity epidemic represents a major public health concern, resulting in a huge unmet medical need. Thankfully, several weight loss drugs have hit the market over the past few years, offering new hope for patients. Zepound is one of the most recent approvals, demonstrating robust safety and efficacy in the realm of weight loss and offering an additional treatment option for patients.

How does Zepbound work?

Zepound contains tirzepatide, its major active ingredient. Tirzepatide provides dual action, acting as a glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) receptor agonist. You may recognize the term “GLP-1” agonist, as weight loss drugs like Ozempic boast this same mechanism. But because Zepound also is a GIP agonist, it may cause different results.

Via this mechanism of action, tirzepatide promotes the release of insulin from the pancreas. Insulin is a key hormone implicated in blood sugar management. Through its glucose-lowering effects, tirzapetide can help successfully manage diabetes. In terms of weight loss, tirzepatide slows gastric emptying, which is the process by which food moves through the digestive tract. Because food movement is delayed, you are satiated for longer, thus lowering your food intake. As a result, weight loss can occur.

Zepbound vs. Mounjaro: Understanding the Differences

Zepbound and Mounjaro, while containing the same active ingredient, tirzepatide, are distinct in their medical indications and dosages. Zepbound is primarily approved for weight loss management in adults who are either obese or overweight with at least one weight-related condition, such as high blood pressure or type 2 diabetes. Its use is an adjunct to diet and exercise. Mounjaro, on the other hand, is indicated for the control of blood sugar levels in adults with type 2 diabetes, also in conjunction with diet and exercise. The dosages of these medications differ to suit their respective purposes. Zepbound typically has a maintenance dose ranging between 5 to 10 mg once weekly, whereas Mounjaro is often prescribed at a maintenance dose of 5 mg once weekly. This difference in dosage reflects the varied therapeutic goals of each medication, with Zepbound focusing on weight management and Mounjaro targeting blood sugar control.

Comparison with Other Weight Loss Drugs

In the evolving landscape of weight loss medications, Zepbound emerges as a noteworthy contender alongside established drugs like Ozempic, Wegovy, and Mounjaro. Each of these medications has unique characteristics that set them apart in the realm of weight management.

Zepbound is distinguished by its dual-action mechanism, targeting both GLP-1 and GIP receptors. This dual approach potentially offers more comprehensive metabolic benefits compared to drugs that only target GLP-1 receptors. Zepbound is specifically indicated for weight loss in adults who are obese or overweight with associated conditions like high cholesterol or type 2 diabetes.

 Ozempic, primarily known for its role in managing type 2 diabetes, also impacts weight loss. Its active ingredient, semaglutide, functions as a GLP-1 receptor agonist, similar to Zepbound. However, Ozempic’s primary focus remains on blood sugar control rather than direct weight loss.

 Wegovy, also containing semaglutide, is more directly comparable to Zepbound in its weight loss orientation. Like Zepbound, it targets the GLP-1 receptor but lacks the GIP receptor action. Wegovy is approved for chronic weight management in obese or overweight adults with at least one weight-related condition.

 Mounjaro, containing tirzepatide like Zepbound, is primarily indicated for type 2 diabetes management. Its dual-action mechanism is similar to Zepbound, targeting both GLP-1 and GIP receptors, which makes it a direct competitor in terms of mechanism of action.

Here’s a comparison table for a quick overview:

Drug Name

Active IngredientPrimary IndicationMechanism of Action

Target Receptors

ZepboundTirzepatideWeight LossDual-actionGLP-1 and GIP
OzempicSemaglutideType 2 DiabetesGLP-1 agonistGLP-1
WegovySemaglutideWeight LossGLP-1 agonistGLP-1
MounjaroTirzepatideType 2 DiabetesDual-actionGLP-1 and GIP

This comparison underscores Zepbound’s unique positioning in the market, particularly for those seeking a weight loss solution with a broader metabolic impact. However, the choice of medication should always be tailored to individual health profiles and needs, in consultation with healthcare professionals.

Is tirzepatide already approved?

Zepbound contains the active ingredient tirzepatide. Tirzepatide is also the active ingredient contained within Mounjaro, an already-approved medication. The difference between the two medications relates to their indication and dose. The differences are as follows:

  • Indication. Mounjaro is indicated for blood sugar control in adults with type 2 diabetes in adjunct to diet and exercise. On the contrary, Zepbound is indicated for weight loss in addition to diet and exercise in obese or overweight individuals with at least one weight-related condition.
  • Dose. Mounjaro is typically given at a maintenance dose of 5 mg once weekly, while Zepbound is usually administered at a maintenance dose of between 5 to 10 mg once weekly.

Overall, the side effect profile between the two are similar, although more side effects may be experienced with Zepbound because the dose is larger.

What do the studies say?

Up until now, tirzepatide has only really been studied for treatment of type 2 diabetes. The approval of Zepbound, however, was based on two randomized, double-blind, placebo-controlled studies. These studies enrolled adult patients that were either obese or overweight with a minimum of one weight-associated condition. One trial enrolled patients without diabetes, while one trial enrolled patients with diabetes. The average body weight of individuals starting the trial without diabetes was 231 pounds with an average BMI of 38 kg/m2. The average body weight of individuals starting the trial with diabetes was 222 pounds with an average BMI of 36 kg/m2. In total, over 2,500 individuals were administered a once weekly injection of Zepbound at different doses for a course of 72 weeks.

Findings demonstrated robust results. Zepbound induced statistically significant decreases in body weight at all three doses compared to placebo. At the highest dose, individuals lost an average of 12 to 18 percent of their body weight versus those on placebo. Additionally, more patients had a minimum of a five percent decrease in weight when taking Zepbound versus those taking placebo. It is important to note that these results were seen when Zepbound was taken as adjunct to diet and exercise.

In addition to efficacy, the two trials characterized Zepbound’s safety profile. The most common side effects observed included nausea, vomiting, diarrhea, constipation, stomach pain, drowsiness, allergic reactions, burping, injection site reactions, gastroesophageal reflux disease (GERD), and hair loss. There are a few warnings that are also associated with use of Zepbound for weight loss, which will be discussed later.

How do you take Zepbound for weight loss?

As aforementioned, the active ingredient tirzepatide has been previously approved under the brand name Mounjaro for type 2 diabetes. It is important to distinguish that although Zepbound and Mounjaro both contain tirzepatide, they are approved for different doses because of their different indications.

Zepbound is administered via a subcutaneous (under the skin) injection on a once weekly basis with or without meals. It can be administered in the upper arm, abdomen, or thigh, although injections sites should be rotated with each dose. Zepbound is available in the following strengths: 2.5, 5, 7.5, 10, 12.5, and 15 mg per 0.5 mL, contained within a single-dose pen.

Based on Zepbound’s label approved by the FDA, the suggested starting dose is 2.5 mg once weekly. After this initial dose, the dose can be increased every four weeks in increments of 2.5 mg. The suggest target dose is either 5, 10, or 15 mg once weekly, with a maximum dose being 15 mg once weekly.

Safety and Side Effects

Zepbound, known generically as tirzepatide, has shown promise in weight loss management but comes with its own set of side effects and precautions. Common side effects include gastrointestinal issues such as nausea, diarrhea, vomiting, constipation, abdominal pain, and indigestion. Some patients may also experience increased lethargy, injection-site reactions, and hair loss. More severe side effects can include kidney problems, gallbladder issues, serious allergic reactions, low blood sugar, vision changes, and even depression or suicidal thoughts. It’s crucial for patients with a family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 to avoid Zepbound due to the risk of thyroid tumors. Close medical supervision is essential when using this medication to monitor for these side effects and manage them effectively.

What are the risks of Zepbound?

Like with any drug, Zepbound carries a few risks of adverse effects. These are important to be aware of so you can look out for signs and symptoms of these conditions. Such risks include:

  • Low blood sugar. It is important to remember that in addition to helping with weight loss, Zepbound is an antidiabetic agent that lowers blood sugar. When used with other medications aimed at lowering blood sugar, it can cause dangerously low blood sugar levels. This can manifest as symptoms such as shakiness, headache, sweating, heartbeat changes, and paleness.
  • Kidney injury. Patients should have their kidney function monitored.
  • Gallbladder disease. Some patients experienced gallbladder issues in clinical trials.
  • Allergy. If allergic reactions occur, such as swelling or anaphylaxis, seek medical attention immediately and stop taking Zepbound.
  • Acute pancreatitis. When this happens, the pancreas becomes inflamed.
  • Suicidal thoughts. Patients should be monitored for signs of depression, suicidal ideation, or suicidal behavior.

In addition to these adverse effects, there are certain individuals in which Zepbound is contraindicated. For example, individuals that have a family or personal history of medullary thyroid carcinoma or individuals with Multiple Endocrine Neoplasia syndrome type 2 should not take Zepbound. Additionally, people that have known allergy to a component of Zepbound should also not take Zepbound.

There are also a few drug interactions to be aware of before starting Zepbound. As aforementioned, Zepbound can cause hypoglycemia, which can be very dangerous. This risk can occur when taking Zepbound concomitantly with insulin or insulin secretagogues, like sulfonylureas. Thus, if you take these, your provider may need to adjust the dosing of your medications.

You may recall that Zepbound works by prolonging gastric emptying. In doing so, it not only affects the food you eat but also any medications that you take orally. Caution should be used when taking other medications orally, as Zepbound might change the way in which they are absorbed. Certain drugs like warfarin (a blood thinner) that have a narrow therapeutic index may be impacted. Those taking oral birth control are advised to switch to a non-oral birth control method for this same reason.

Zepbound vs. Mounjaro: Understanding the Differences

Zepbound and Mounjaro, while containing the same active ingredient, tirzepatide, are distinct in their medical indications and dosages. Zepbound is primarily approved for weight loss management in adults who are either obese or overweight with at least one weight-related condition, such as high blood pressure or type 2 diabetes. Its use is an adjunct to diet and exercise. Mounjaro, on the other hand, is indicated for the control of blood sugar levels in adults with type 2 diabetes, also in conjunction with diet and exercise. The dosages of these medications differ to suit their respective purposes. Zepbound typically has a maintenance dose ranging between 5 to 10 mg once weekly, whereas Mounjaro is often prescribed at a maintenance dose of 5 mg once weekly. This difference in dosage reflects the varied therapeutic goals of each medication, with Zepbound focusing on weight management and Mounjaro targeting blood sugar control.

Expert Opinions

Medical professionals emphasize the importance of managing expectations with Zepbound. While it has shown significant results in trials, with patients losing an average of 15% to 26% of their body weight, it’s not a one-size-fits-all solution. The drug’s dual mechanism, targeting both GLP-1 and GIP receptors, may offer advantages over other medications like Wegovy, which only targets GLP-1. However, experts caution that despite fewer reported side effects like GI discomfort compared to semaglutide-based drugs, individual responses can vary. They also stress the importance of accompanying lifestyle changes, including a balanced diet and regular exercise, to enhance the effectiveness of Zepbound in weight management. The cost of Zepbound, around $1,060, can vary depending on insurance coverage, and patients are advised to check with their providers.

Conclusion

In summary, Zepbound boasts a robust safety and efficacy profile in the realm of weight management. As a result, it will join the clan of other weight loss medications as a potential new treatment option for overweight or obese individuals. If you are interested in taking Zepbound, talk to your provider about whether or not it will be right for you.