Key Points

Weight loss may begin within the first 4 weeks of treatment with Wegovy, but the full effects of treatment may not be seen for several months or longer.

• In studies, weight loss in adults was assessed over a 68-week period.
• Patients taking Wegovy lost an average of 35 lbs (15.9 kg), or about 15% of their body weight compared to 6 lbs (2.7 kg), or roughly 2.5% body weight in the placebo group.
• Overall, after 68 weeks, 83% of adults taking Wegovy lost 5% or more of their weight compared to 31% of adults taking a placebo.
• In adolescents 12 years of age and older, Wegovy led to a 16.1% decrease in body mass index (BMI) at week 68, compared to a 0.6% BMI decrease with placebo. In addition, 77% of patients in the Wegovy group had a BMI reduction of at least 5% vs. 20% in the placebo group.

Wegovy doses are slowly increased when you first start treatment to help reduce side effects like nausea or diarrhea. It typically takes 17 weeks to reach the full maintenance dose of Wegovy, based on how well you tolerate the medicine.

The maintenance dose of Wegovy (semaglutide) is 2.4 mg injected subcutaneously (under the skin) once-a-week, with or without meals. It comes in a pre-filled, single-dose pen. Your healthcare provider will teach you how to give these injections so you can use it at home.

Wegovy studies and weight loss

In randomized, placebo-controlled studies conducted by Novo Nordisk, the manufacturer of Wegovy, weight loss was assessed over a 68-week period in 1,961 adults taking either Wegovy or a placebo. Both groups were instructed to also follow a plan of reduced-calorie meals and increased physical activity.

In these studies, patients were classified as either obese (BMI ≥30) or with excess weight (BMI ≥27) with a weight-related medical problem (such as high blood pressure or high cholesterol). The average starting weight for both groups was about 232 lbs (105.4 kg). Both groups were instructed to also follow a plan of reduced-calorie meals and increased physical activity.

Over the 68-week period, adults taking Wegovy lost an average of 35 lbs (15.9 kg), or about 15% of their body weight. Those taking placebo lost an average of 6 lbs (2.7 kg), or roughly 2.5% their body weight.

How many people lose weight with Wegovy?

In the 68-week studies:

• 83% of adults taking Wegovy lost 5% or more of their weight compared to 31% of people taking a placebo.
• 66% of adults taking Wegovy lost 10% or more of their weight compared to 12% of people taking a placebo.
• 48% of adults taking Wegovy lost 15% or more of their weight compared to 5% of people taking a placebo.

However, some people dropped out of the research studies. In clinical trials with 2,116 participants, 6.8% of people in the Wegovy group and 3.2% in the placebo group discontinued treatment due to stomach side effects like nausea, vomiting, and diarrhea.

What are the top 5 most common side effects with Wegovy?

The top 5 most common side effects are:

• Nausea
• Diarrhea
• Vomiting
• Constipation
• Abdominal (stomach-area) pain

Stomach side effects are most common when starting treatment but decrease over time in most people. Headache, fatigue, and hypoglycemia have also been reported.

Adolescents treated with Wegovy had greater incidences of gallbladder problems including gallstones, low blood pressure, rash, and itching (when compared to adults treated with Wegovy).

Related: Side Effects with Wegovy (in detail)

How does Wegovy work?

Wegovy (semaglutide) is classified as a glucagon-like peptide-1 (GLP-1) receptor agonist. It works by acting like a hormone in your body that signals brain receptors involved in your appetite and food intake. It can reduce your appetite which may help you eat less and lead to weight loss. It also slows down how quickly the stomach empties, which makes you feel fuller for a longer period of time.

Wegovy is used in addition to diet and exercise for long-term weight management in:

• adults who are either obese (BMI ≥30 kg/m²) or overweight (BMI ≥27 kg/m²) with at least one weight-related condition such as high blood pressure, type 2 diabetes, or high cholesterol
• adolescents 12 years and older with an initial BMI at or above the 95th percentile for age and sex (based on growth charts)

Other prescription drugs that also contain semaglutide are Ozempic (injection) or Rybelsus (oral tablets). These brands are only approved to treat type 2 diabetes, together with diet and exercise.

This is not all the information you need to know about Wegovy (semaglutide) for safe and effective use and does not take the place of your doctor’s directions. Review the full Wegovy (semaglutide) information and discuss this information and any questions you have with your doctor or other health care provider.