Earlier this month, the United States Food and Drug Administration (FDA) approved the medication Zepbound for the treatment of chronic obesity. The injectable medication, manufactured by Eli Lilly, has tirzepatide as its active ingredient, which was previously approved in May 2022 for the treatment of type 2 diabetes under the name Mounjaro.
The tirzepatide joins a similar medication called semaglutide, which was also initially developed for diabetes treatment under the name Ozempic and has since been approved for obesity treatment under the name Wegovy. Studies on both have shown high efficacy in treating diabetes and obesity.
What is the difference between Zepbound and Wegovy? How do they work and how well do they work? How long do they need to be used? What are the possible side effects? Should people consider more affordable versions of medications sold by some pharmacies on the Internet? And who should consider taking these medications – and who should not?
There are many questions.
Below is a brief summary of the use of these medications; however, nothing replaces a medical consultation. Before considering using these medications, talk to your trusted doctor.
What is the difference between Zepbound and Wegovy? How do they work?
Both are injectable medications that should be used once a week. Both were initially approved to treat type 2 diabetes, but clinical trials have also shown that they induced significant weight loss. Wegovy is already on the market, and Zepbound has just been approved by the FDA and should be available later this year.
Both are in the class of medications known as GLP-1 mimetics. That is, they mimic the digestive hormone glucagon-like peptide 1, or GLP-1, which is released by the intestines when we eat. GLP-1 stimulates insulin production, which reduces blood glucose levels. The hormone also suppresses appetite and promotes a feeling of fullness.
In addition to mimicking GLP-1, tirzepatide mimics another intestinal hormone called gastric inhibitory polypeptide, or GIP, which scientists believe has a similar effect on the body as GLP-1.
Do these medications work well for weight reduction?
Both medications seem to work well. A March 2021 study on semaglutide, published in The New England Journal of Medicine, showed that people taking the medication lost an average of 14.9% of their body weight in about a year, compared to 2.4% in the placebo group. A September 2022 study published in JAMA Network Open found that the average weight loss after six months was about 12.3 kilograms.
How long do these medications need to be taken?
Currently, the understanding is that tirzepatide and semaglutide need to be taken for life. If stopped, much of the weight loss will be reversed.
Is there a risk of side effects when taking these medications?
Yes, there is. Many people experience gastrointestinal issues such as nausea, diarrhea, vomiting, and constipation. In rare cases, the medications have been associated with problems in the pancreas, gallbladder, and stomach. Since tirzepatide and semaglutide are recent medications, long-term side effects are not known.
Should people consider cheaper versions of these medications sold by some pharmacies on the Internet?
The safest option is to buy medications made directly by the manufacturers, which are Eli Lilly for tirzepatide and Novo Nordisk for semaglutide. This requires a prescription from your doctor and a visit to a pharmacy to obtain the medications.
The FDA website has a resource to check if a website may be an illegal pharmacy distributing potentially dangerous medications.
Who should consider taking these medications – and who should not?
Obesity is a chronic medical condition. Individuals should take these medications, after consulting with their doctor, if they have this condition – and not if they are simply dissatisfied with their appearance and trying to lose a few pounds.
Patients are eligible to use Wegovy if they have a body mass index, or BMI, of 27 or higher. Zepbound is approved for those with a BMI of 30 or higher. It is advised that people use the medications along with lifestyle changes, including increased physical activity and dietary re-education.
Source: CNN