GLP-1 weight loss medications, explained

GLP-1 medications have changed the conversation about weight loss in the last few years. Drugs in this class can produce 15 to 22 percent body weight loss on average in clinical trials (NEJM, 2021). That is meaningful. It is also new enough that there is a lot of noise. This paper walks through what these medications actually do, who they tend to help, and what to plan for if you start one.

What GLP-1 medications are

GLP-1 stands for glucagon-like peptide 1. Your gut releases this hormone naturally after a meal. It tells your pancreas to release insulin, slows how fast food leaves your stomach, and signals to your brain that you are full.

The medications you may have heard about (semaglutide, sold as Wegovy and Ozempic, and tirzepatide, sold as Zepbound and Mounjaro) are synthetic versions of this hormone. They were first approved for type 2 diabetes. The weight loss was a side effect striking enough that, after additional trials, the FDA approved higher doses specifically for chronic weight management (FDA, 2021 and 2023).

Tirzepatide is a dual agonist. It targets the GLP-1 receptor and a second receptor called GIP. Head-to-head data suggests tirzepatide produces slightly more weight loss than semaglutide on average (NEJM, 2022).

How they help with weight loss

Three mechanisms matter most:

1. Appetite signaling. The medication amplifies the same satiety pathway your body uses naturally. Most patients describe a quieter “food noise” and an easier time stopping when full.
2. Gastric emptying. Food leaves the stomach more slowly, so a smaller meal lasts longer.
3. Glucose handling. Insulin response improves. This matters most for people with prediabetes or type 2 diabetes, where weight loss and glucose control reinforce each other.

The result is a smaller caloric intake without the constant willpower battle. The medication does not change what you eat. It changes how much you want to eat.

Who tends to be a fit

Current FDA labeling supports use in adults with:

• A body mass index of 30 or higher, or
• A body mass index of 27 or higher plus at least one weight-related condition such as high blood pressure, type 2 diabetes, sleep apnea, or fatty liver disease.

People who do best on these medications generally combine the prescription with three habits: protein-forward meals, resistance training a few times per week, and regular sleep. The medication makes the math easier. It does not replace the math.

What to expect in the first eight weeks

Most clinicians (Station Medical included) start at a low dose and step up every four weeks. The early period is when side effects show up:

• Nausea, especially in the first one to two weeks after a dose increase.
• Reflux, constipation, or diarrhea.
• Reduced appetite (the desired effect, but it can feel surprising).

These usually fade. Slow titration, smaller meals, and adequate hydration help. If side effects do not settle, the dose can be paused or stepped back.

What to plan around

A few items worth thinking through in advance:

• Muscle preservation. Any large caloric deficit can cost lean mass. Prioritize 0.7 to 1.0 gram of protein per pound of goal body weight per day, and strength train two to three times a week.
• Bone density. Long-term data is still being collected. For patients with osteopenia or osteoporosis, weight-bearing activity becomes more important, not less.
• Pregnancy. GLP-1 medications are not used during pregnancy or while trying to conceive. Most labels recommend stopping at least two months before attempting pregnancy.
• Pancreatitis history. A personal history of pancreatitis is a relative contraindication and needs a careful clinical review.
• Medullary thyroid cancer. A personal or family history is a contraindication.

What it costs and how access works

Coverage is variable. Some insurance plans cover semaglutide or tirzepatide for obesity, some only cover them for type 2 diabetes, and some do not cover them at all. Compounded versions exist while certain brand-name formulations have been on the FDA shortage list, though that landscape changes frequently (FDA Drug Shortage Database, 2024).

At Station Medical, weight management is provider-supervised. The initial visit covers labs, an honest conversation about goals and history, and a plan that may or may not include a GLP-1 medication. Visits include follow-up at intervals that fit the dose schedule.

How long you stay on it

The current evidence suggests the medication works while you take it and that some weight returns when it is stopped (JAMA, 2022). That does not mean you have to stay on it forever. Many patients use it for a defined period to build new habits, then taper. Others use it indefinitely the same way someone with high blood pressure uses an antihypertensive. The right answer is individual.

The next step

A short visit is enough to know whether this is the right tool for you, or whether a different approach (lifestyle plan, sleep evaluation, hormone workup, or surgical referral) is a better fit. We will not start a medication you do not need.