GLP-1 Medications Explained: Ozempic, Wegovy, and Zepbound — What’s the Difference?

What is a GLP-1 receptor agonist?

GLP-1 (glucagon-like peptide-1) is a hormone your body naturally produces in response to eating. It signals to your brain that you're full, slows the rate at which food leaves your stomach, and reduces the secretion of glucagon (a hormone that raises blood sugar).

GLP-1 receptor agonists are medications that mimic this hormone — but stay active in your body much longer than the natural hormone does. The result: reduced hunger, slower digestion, lower blood sugar, and over time, significant weight loss.

Semaglutide: Ozempic vs. Wegovy

Both Ozempic and Wegovy contain the same active ingredient — semaglutide. The difference is:

• Ozempic is FDA-approved for type 2 diabetes (max dose 2 mg weekly). Many physicians prescribe it off-label for weight loss.
• Wegovy is the same drug, but FDA-approved specifically for chronic weight management at a higher max dose (2.4 mg weekly). It's the version most insurance plans cover for obesity.

Both are once-weekly subcutaneous injections (under the skin). The pen is pre-filled and the needle is tiny — most patients describe it as nearly painless.

Tirzepatide: Mounjaro vs. Zepbound

Tirzepatide is a newer medication that targets two hormones — GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). This dual action results in even greater weight loss in clinical trials.

• Mounjaro is FDA-approved for type 2 diabetes.
• Zepbound is FDA-approved for chronic weight management.

Clinical trials showed Zepbound users losing an average of 22.5% of body weight at the highest dose — the most impressive weight loss results ever seen in a non-surgical intervention.

Side effects to know about

The most common side effects of GLP-1 medications are gastrointestinal — nausea, vomiting, constipation, and diarrhea. These are most common when starting or increasing the dose, and typically improve over time. Starting at a low dose and titrating up slowly (which is the standard approach) significantly reduces these side effects.

More serious but rare risks include pancreatitis, gallbladder disease, and a theoretical risk of thyroid C-cell tumors (seen in rodent studies — personal or family history of medullary thyroid cancer is a contraindication). Li Health will review your complete medical history before prescribing.

Which medication is right for me?

There's no one-size-fits-all answer. The right choice depends on your medical history, whether you have diabetes, what your insurance covers, and your personal preferences. As a board-certified Obesity Medicine physician, Li Health will evaluate all of these factors during your visit and recommend the most appropriate option.