You've probably seen the ads, heard the celebrity stories, or noticed friends and family members mentioning them: Ozempic, Wegovy, Mounjaro, Zepbound. These are all part of a class of medications called GLP-1 receptor agonists, and they've fundamentally changed what's possible in medical weight loss. But there's also a lot of hype, some real misinformation, and a fair amount of confusion about which medication does what. Here's a straightforward guide.

What GLP-1 medications actually are

"GLP-1" stands for glucagon-like peptide-1, a hormone your body naturally produces after eating. It plays a role in regulating blood sugar, signaling fullness, and slowing digestion. GLP-1 medications mimic this hormone and amplify its effects, which is why they were originally developed to treat type 2 diabetes. The weight loss came later — as researchers noticed that patients on GLP-1 medications for diabetes were also losing significant amounts of weight, dedicated weight loss versions were developed.

The main options, explained

All are once-weekly injections that patients administer themselves at home, similar to how many people already administer insulin.

How much weight loss can you actually expect?

Clinical trials give us reasonable expectations. In major studies:

Individual results vary widely. Some patients lose considerably more; others less. What's consistent across studies is that these medications produce weight loss substantially greater than lifestyle changes alone, especially for patients who have struggled with traditional dieting.

Common side effects

The most common side effects are gastrointestinal — nausea, occasional vomiting, constipation or diarrhea, and reduced appetite (which is, of course, part of how they work). These are usually most noticeable when starting the medication or increasing the dose, and often improve over time. A physician can help you manage these with dose adjustments and simple strategies.

More serious potential side effects — pancreatitis, gallbladder issues, and others — are rare but real, and are part of why appropriate medical supervision matters.

Who is (and isn't) a good candidate

GLP-1 medications for weight loss are generally FDA-approved for adults with a BMI of 30 or higher, or a BMI of 27 or higher with a weight-related condition like type 2 diabetes, high blood pressure, or high cholesterol. They aren't intended for cosmetic weight loss in people who are already at a healthy weight.

They're also not appropriate for people with personal or family history of certain thyroid cancers, active pancreatitis, or a few other specific conditions. Part of the initial evaluation is screening for these.

Weight loss isn't just the medication

An important honest note: GLP-1 medications work best as part of a broader plan that includes attention to nutrition, physical activity, and sustainable lifestyle changes. They're a powerful tool, but they aren't a substitute for the fundamentals — and when patients stop the medication without having built sustainable habits, weight regain is common. A good medical weight loss program addresses both the medication and the underlying patterns.

How Simply Medicine can help

If you're considering medical weight loss, a telemedicine visit is a straightforward way to talk through whether GLP-1 therapy makes sense for you, review your history and any relevant labs, and — if it's a good fit — start treatment with proper medical monitoring. If it's not the right fit, we'll be honest and talk through other options that might work better.

Sources