Zepbound®, made by Eli Lilly, is the newest GLP-1 agonist medication approved by the FDA for weight loss. It contains tirzepatide, the same active ingredient in Mounjaro; this drug is unique in its mechanism of action, being the first and only treatment of its kind that activates both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) hormone receptors.
GLP-1 Weight Loss Medication
Zepbound®, made by Eli Lilly, is the newest GLP-1 agonist medication approved by the FDA for weight loss. It contains tirzepatide, the same active ingredient in Mounjaro; this drug is unique in its mechanism of action, being the first and only treatment of its kind that activates both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) hormone receptors.
Here are six things to know about this in-demand medication before it hits pharmacy shelves.
1. When will Zepbound® be available?
Zepbound® is currently available and has been since the end of last year! Hoewver, even though Zepbound® is available, it's not easy to get. At the time of writing, several doses of Zepbound® are on the FDA shortage list and many have had trouble accessing this medication, even when prescribed.
2. What’s different about Zepbound®, and how does it work?
Zepbound® is a weekly injectable weight-loss drug that contains tirzepatide, the same active ingredient in Mounjaro. Zepbound® and Mounjaro are essentially the same medication with different branding; furthermore they’re available in the same dosages. They have different names because Zepbound® is approved by the FDA to manage weight loss while Mounjaro is approved for Type 2 diabetes. (The same goes for Wegovy and Ozempic, which both contain semaglutide but are approved to treat weight loss and diabetes, respectively.)
More often than not, tirzepatide is described as a GLP-1 drug (including in this article). This is almost correct: Tirzepatide is very similar to GLP-1s, but it’s technically a GLP-1/GIP dual agonist. While GLP-1 drugs mimic the effects of one appetite-regulating hormone, tirzepatide acts on two. This is a small but potentially important difference, as tirzepatide has shown to be even more effective in clinical trials than true GLP-1s. Over 72 weeks, trial participants taking the maximum recommended dose of tirzepatide lost 18% of their body weight, on average. By comparison, the average weight loss in trials for semaglutide was 15% over two years, and 4-6% over 68 weeks for liraglutide.
As with all GLP-1s, tirzepatide is intended to be combined with a reduced-calorie diet and exercise for optimal effects.
3. Who’s Zepbound® for?
Zepbound® is approved for 1) people who have obesity, defined as a body mass index (BMI) of 30 or higher, and 2) people who have a BMI of 27 or higher and also have weight-related comorbidities, such as hypertension. The other two GLP-1 drugs approved for weight loss, Wegovy and Saxenda, have the same qualifications.
4. Could I just take Mounjaro for weight loss instead?
Maybe, but it would cost a lot. The FDA approved Mounjaro for Type 2 diabetes in May 2022. There’s been steady demand to use it off-label for weight loss, but insurance plans are unlikely to cover brand-name drugs for off-label use when other FDA-approved options are available. Without coverage, Mounjaro costs $1,000 per month or more. Zepbound’s® approval won’t affect how insurers cover Mounjaro.
The impending arrival of a tirzepatide medication that’s specifically approved for weight loss is big news because more people will be able to afford to take it.
5. So, Zepbound® will be covered by my insurance? How much will it cost?
Zepbound® will be eligible for coverage for people who meet the diagnostic criteria (having obesity or being overweight and also having a related health condition). But coverage policies will likely vary by plan. Many commercial plans already cover Wegovy and/or Saxenda, and coverage for Zepbound should be similar. Government insurance plans do not currently cover GLP-1s for weight loss.
If your plan covers Zepbound®, the price might be as low as a monthly $25 copay, according to Eli Lilly, the drug manufacturer. If you have commercial insurance that does not cover Zepbound®, the price might be as low as $500 per month. That’s certainly not cheap, but it’s about half the list price for the drug, which is $1,059.
6. What are Zepbound’s® side effects?
In clinical trials, the reported side effects of tirzapetide were similar to those for all GLP-1s. The most common was nausea, followed by other gastrointestinal issues — diarrhea, vomiting, constipation and acid reflux. The FDA approval also mentions burping and hair loss, which have been anecdotally reported for other GLP-1s too. There are more serious side effects and adverse reactions, but they’re rare. You can see the full list in the medication guide, which also has info on contraindications.
GLP-1 Weight Loss Medication
