In a recent poll, KFF found that nearly half of U.S. adults were interested in taking a weight management drug like the increasingly popular Ozempic, Wegovy, and Mounjaro. 

“I can understand why there would be widespread interest in these medications,” says Dr. Alyssa Lampe Dominguez, an endocrinologist and clinical assistant professor at the University of Southern California. “Obesity is a chronic disease that is very difficult to treat. And a lot of the medications that we previously used weren’t as effective.”

Now, there’s a new option available: In November 2023, the FDA approved Zepbound, another weight management medication, developed by the pharmaceutical company Eli Lilly. Zepbound is different from other drugs in many ways, including the fact that it’s proven to be the most effective option so far.

Keep reading to find out more about Zepbound, including who can take it, its side effects, and more. 

What is Zepbound? 

Zepbound, one of the brand names for tirzepatide, is an injectable drug with a maximum dosage of 15 mg per week. It’s based on incretin, a hormone that’s naturally released in the gut after a meal. (Mounjaro is another brand name for tirzepatide.) 

Tirzepatide is considered a dual agonist because it activates the two primary incretin hormones: the glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP) hormones.

According to Dr. Katherine H. Saunders, an obesity medicine physician at Weill Cornell Medicine and co-founder of Intellihealth, tirzepatide is involved with several processes that regulate blood sugar, slow the removal of food from the stomach, and affect brain areas involved in appetite.

This means that people taking the medication feel less hungry and get fuller faster, leading to less food intake and, ultimately, weight loss.

How is Zepbound different from Ozempic?

The medications are different in many ways. Ozempic and Wegovy, which are both brand names for semaglutide, only target the GLP-1 hormone. Studies have shown that Zepbound can lead to a higher percentage of total body weight loss than semaglutide medications. In addition to being more effective, there is some evidence that Zepbound is overall more tolerable than Ozempic or Wegovy. 

“I have seen overall lower rates in severity of side effects with the tirzepatide medications. Mounjaro [tirzepatide] in particular is the one that I’ve used up until this point, but there’s a thought that the GIP component of the medication actually decreases nausea,” adds Lampe Dominguez. “Anecdotally, patients that I have switched from semaglutide or Ozempic to Mounjaro say that they have less side effects with Mounjaro.”

How is Zepbound different from Mounjaro? 

Zepbound and Mounjaro are the same medication—tirzepatide—but they’re approved for different conditions. Zepbound is FDA-approved for weight loss, while Mounjaro is approved for type 2 diabetes. (However, Mounjaro is also at times prescribed off-label for weight loss.) 

What are some of Zepbound’s side effects? 

According to the FDA, side effects include nausea, vomiting, diarrhea, constipation, stomach discomfort and pain, fatigue, and burping. See a more comprehensive list of side effects here. 

Who can take Zepbound?

Zepbound is FDA-approved for adults with obesity (a BMI of 30 or greater) or who have a BMI of 27 or greater with at least one weight-related condition, like high blood pressure, type 2 diabetes, or high cholesterol. 

“I tend to advise patients who don’t meet those criteria to not take these medications because we really don’t know what the risks are,” says Lampe Dominguez, adding that people with lower BMI weren’t included in the medication’s studies. “We don’t know if there are specific risks to using this medication at a lower body mass index [or] if there might be some negative outcomes.”

Both doctors agree that it’s important for people who are interested in starting any weight loss medication to talk to their doctors about the potential risks and benefits. For instance, the FDA notes that Zepbound has caused thyroid tumors in rats, and while it’s unknown if this could also happen to humans, the agency said the medication shouldn’t be used in patients with a personal or family history of medullary thyroid cancer. 

“Zepbound is a powerful medication that can lead to severe side effects, vitamin deficiencies, a complete lack of appetite, or too much weight loss if prescribed without the appropriate personalization, education, and close monitoring,” says Saunders.

“With all of these medications, and particularly with Zepbound, we would want to make sure that [patients] don’t have a family history of a specific type of thyroid cancer called medullary thyroid cancer,” says Lampe Dominguez.

How long should people take Zepbound for?

“Anti-obesity medications like Zepbound are not meant for short-term weight loss, but long-term treatment of obesity, which is a chronic disease,” explains Saunders. “We prepare our patients to be on the medication (or some type of medical obesity treatment) long term for their chronic disease, which is only controlled for the duration of time they’re being treated.”

For more information, talk to your health care provider.

This article first appeared on Public Good News and is republished here under a Creative Commons license.