Wegovy is a GLP-1 receptor agonist, a class of injectable medications that mimic a natural gut hormone to reduce appetite and promote weight loss. Its active ingredient is semaglutide, the same compound found in the diabetes drug Ozempic, though Wegovy is specifically approved for weight management and is given at higher doses.
How GLP-1 Receptor Agonists Work
Your body naturally produces a hormone called GLP-1 (glucagon-like peptide-1) after you eat. It signals your brain that you’re full and slows the rate at which food leaves your stomach. Semaglutide is a synthetic version of this hormone, engineered to last much longer in the body, which is why a single weekly injection is enough.
The drug works through several overlapping pathways. It slows gastric emptying, meaning food stays in your stomach longer and you feel full sooner during a meal. At the same time, it acts on appetite centers in the brain. In the hypothalamus, it increases the release of chemicals that suppress hunger while dialing down the ones that stimulate it. It also appears to reduce the reward value of food by influencing dopamine signaling, so cravings for high-calorie foods become less intense. The combined effect is that people on Wegovy simply eat less without feeling like they’re fighting constant hunger.
Who Wegovy Is Approved For
The FDA has approved Wegovy for adults with obesity (a BMI of 30 or higher) or adults with overweight (BMI of 27 to 29.9) who also have at least one weight-related health condition such as high blood pressure, high cholesterol, or type 2 diabetes. It’s also approved for adolescents aged 12 and older whose BMI falls at or above the 95th percentile for their age and sex.
Beyond weight loss, Wegovy carries additional approvals that distinguish it from other weight management drugs. It’s indicated to reduce the risk of major cardiovascular events (heart attack, stroke, or cardiovascular death) in adults with established heart disease who also have obesity or overweight. More recently, it received approval for treating a form of fatty liver disease called MASH (formerly known as NASH) with moderate to advanced scarring.
Wegovy vs. Ozempic
Both Wegovy and Ozempic contain semaglutide, but they’re prescribed for different purposes at different doses. Ozempic is approved to improve blood sugar control in adults with type 2 diabetes and tops out at 2 mg per week. Wegovy is approved for weight management and can go up to 2.4 mg per week at the standard maintenance dose, with a newer option to increase to 7.2 mg weekly for people who tolerate the lower dose but need additional weight loss. That higher ceiling is the main pharmacological difference: more semaglutide, targeted at a different goal.
How the Dose Ramps Up
Wegovy uses a gradual five-step escalation schedule designed to give your body time to adjust and reduce the chance of stomach-related side effects. You start at 0.25 mg once weekly for the first four weeks, then move to 0.5 mg for weeks five through eight, 1 mg for weeks nine through twelve, and 1.7 mg for weeks thirteen through sixteen. From week seventeen onward, the maintenance dose is typically 2.4 mg for adults (1.7 mg is also an option) and 2.4 mg for adolescents. If a particular step causes too many side effects, your prescriber can hold you at that dose for an extra four weeks before moving up.
How It’s Taken and Stored
Wegovy comes as a prefilled, single-use pen that you inject under the skin once a week. Common injection sites are the stomach, thigh, or upper arm, and you can give yourself the shot on any day of the week as long as you keep the same day each week. The pens need to be stored in the refrigerator between 36°F and 46°F. If you need to carry one with you, it can stay at room temperature (up to 86°F) for up to 28 days in its original carton. The pens should never be frozen and should be kept out of direct light.
Common Side Effects
Because semaglutide slows digestion and acts on gut receptors, gastrointestinal symptoms are the most frequent side effects. Nausea is the most common, followed by diarrhea, vomiting, constipation, and abdominal pain. These tend to be worst during the dose escalation phase and often improve once your body adjusts to each new level. Other reported side effects occurring in at least 5% of patients include headache, fatigue, dizziness, bloating, acid reflux, gas, and stomach flu-like symptoms.
The Boxed Warning on Thyroid Tumors
Wegovy carries the FDA’s most serious label warning, a boxed warning, related to thyroid tumors. In animal studies, semaglutide caused thyroid C-cell tumors at doses similar to those used in humans. Whether this risk translates to people is still unknown. Because of this uncertainty, Wegovy is not prescribed to anyone with a personal or family history of medullary thyroid carcinoma or a rare condition called Multiple Endocrine Neoplasia syndrome type 2. Signs to be aware of include a lump in the neck, difficulty swallowing, shortness of breath, or persistent hoarseness.