Wegovy (semaglutide) is a weight loss medicine. The FDA first approved Wegovy in 2021 to help people who are overweight or have obesity lose weight and keep it off. In 2024, Wegovy was also approved to help lower the risk of death due to heart disease, heart attack, and stroke in adults with known heart conditions who also have excess weight or obesity. Wegovy should be used along with eating fewer calories and being more physically active.
How Does Wegovy Work to Reduce Weight?
Semaglutide works by activating a protein called GLP-1, which belongs to a group of hormones called incretins. Incretins are naturally produced by the intestine as soon as food enters your body and stimulate the production of insulin, a hormone that helps digest sugar.
GLP-1 also helps control your appetite by working in your brain to slow the movement of food through your stomach. This makes you feel full faster and stay full longer after eating. As a result, you may eat less and lose weight.
It is not clear how Wegovy lowers the risk for diseases of the heart and blood vessels (cardiovascular diseases).
Is Wegovy Right for Me?
Wegovy may be the right choice for you if:
- You are an adult with a heart condition and excess weight or obesity, and you want to lower the risk of death from heart diseases, heart attack, and stroke.
- You are an adult with excess weight and have at least one other health problem because of it, and you want to lose weight and keep it off.
- You are 12 years old or older, have obesity, and want to lose weight and keep it off.
Your health care provider will measure your weight and height and calculate your body mass index (BMI) by dividing your weight (in kilograms) by your height (in meters) squared. If your BMI is 27 or more, you have excess weight. If your BMI is 30 or more, you have obesity. Your doctor will also examine you and review your medical history to decide if Wegovy is right for you.
How Was Wegovy Studied for Weight Loss?
Several studies were done on the risks and benefits of Wegovy in adults and adolescents ages 12 and older with excess weight.
- Weight loss studies: Six studies looked at how Wegovy, along with eating fewer calories and being more physically active, can help people lose weight. Some of these studies included people with type 2 diabetes, one study focused only on adolescents, and one study included only East Asian people from Japan and South Korea. Of these studies, three of the adult studies and the adolescent study focused on how effective and safe Wegovy was in helping people with excess weight to lose weight.
The main questions these studies wanted to answer were:
- How much does body weight change in people who get Wegovy?
- How many people will lose at least 5% of their body weight after getting Wegovy?
To learn this, researchers measured the weight of the people in each study at both the start and at the end of the study.
- Heart study: One study looked at how Wegovy affects people with heart disease and excess weight. It examined how adding Wegovy to regular heart medicines, along with a healthy diet and physical activity, lowers the risk of heart attack, stroke, and death from heart disease. People with diabetes were not included in this study.
The main question this study wanted to answer was:
- How long does it take for people with excess weight and heart disease who get Wegovy to experience a heart attack or stroke, or die of a heart disease, compared to those who do not get it?
To learn this, researchers measured the time to the first heart attack, first stroke, or death from heart disease in the people studied.
What Medicines Did the People in the Studies Take?
In all studies, people were randomly selected to get either Wegovy or placebo. The placebo looked like Wegovy but didn’t contain any medicine. Neither the people in the study nor the doctors knew who got Wegovy or the placebo.
In addition, in all studies, both the people who got Wegovy and those who got placebo met regularly with a diet expert to receive guidance for a healthy diet and physical activity throughout the study.
Who Was in the Studies?
To take part in the weight loss studies, people had to:
- Be at least 18 years old in the adult studies
- Be at least 12 years old but younger than 18 in the study on adolescents
- Have obesity or excess weight and at least one health problem related to excess weight
- Have tried to lose weight through dieting
In addition, in studies that included people with type 2 diabetes, individuals had to have an HbA1c level between 7% and 10%.
To take part in the heart study, people had to:
- Be at least 45 years old
- Have obesity or excess weight
- Have a history of heart disease, such as a previous heart attack, a previous stroke, certain artery diseases due to narrowing or blockage (called PAD), procedures to restore blood flow (such as bypass surgeries and angioplasties to open blocked arteries), or an amputation due to blocked arteries.
Who Was Excluded From the Studies?
People could not be in weight loss studies if they had experienced a weight change of more than 5 kilograms (11 pounds) in the 3 months before the study. In one of the studies, people who had pancreas inflammation within 6 months before the study, had weight loss surgery, or took weight loss medicines within 3 months before the study could not participate.
In addition, in studies that included people with type 2 diabetes:
- Those with certain types of eye diseases caused by diabetes could not be in the study.
- Those with certain kidney problems could not be in the study.
People could not be in the heart study if they had:
- Certain severe heart or blood circulation problems in the 2 months before the study
- Planned procedures to restore blood flow (such as bypass surgeries and angioplasties to open blocked arteries)
- Class 4 heart failure
- A history of diabetes
- A history of inflammation of the pancreas
- Certain kidney problems
- A history of certain cancers within 5 years before the study
What Were the Study Populations?
Weight loss studies
Adults
- A total of 2,116 people got Wegovy.
- The average age across adult studies was 48.
- About 71% of the people in the studies were women.
- About 72% of the people in the studies were White, 14% Asian, 9% Black or African American, and 13% Hispanic or Latino.
- At the beginning of the studies, about 42% of people in the studies had high blood pressure, 19% had type 2 diabetes, 43% had high levels of fat in their blood (dyslipidemia), 28% had a BMI of greater than 40, and 4% had heart disease.
Adolescents
- A total of 201 adolescents took part in the study.
- A total of 134 adolescents got Wegovy.
- The average age was about 15.
- About 38% of the people in the study were boys.
- About 79% of the people in the study were White, 8% Black or African American, 2% Asian, 11%Hispanic or Latino, and 11% were other races.
- At the beginning of the study, the average weight of the adolescents was 107.5 kilograms (237 pounds) and their average BMI was 37.
Heart study
- A total of 17,604 people took part in the heart study.
- A total of 8,803 got Wegovy.
- The average age was 62.
- A total of 72% of the people in the study were men.
- About 84% of the people in the study were White, 4% were Black or African American, 8% were Asian, and 10% were Hispanic or Latino.
- At the beginning of the study, the average body weight was 97 kilograms (214 pounds) and the average BMI was 33.
- About 76% of the people in the study had a previous heart attack, 23% had a previous stroke, 9% had artery diseases, and 24% had a history of heart failure.
- People were taking their regular heart and blood circulation medicines in addition to getting Wegovy during the study: A total of 90% were taking medicines to treat high blood levels of fat and 86% were taking antiplatelet medicines. Additionally, 74% were taking medicines to lower blood pressure from groups called ACE inhibitors or ARBs, and 70% were taking medicines from a group called beta-blockers.
- A total of 10% had moderate kidney problems, and fewer than 1% had severe kidney problems.
How Long Were the Studies?
Each weight loss study was 68 weeks (about 16 months), and the heart study lasted about 4 years.
What Were the Main Benefits of Wegovy Seen in Studies?
Weight loss studies
People in both adult and adolescent studies who got Wegovy, along with eating fewer calories and being more physically active, lost significantly more weight than those who made changes to their diet and exercise without getting Wegovy.
Adults
In the three main adult studies, people who got Wegovy lost more weight than those who did not get Wegovy:
- In one study, people who got Wegovy lost about 12% more weight than those who did not get Wegovy.
- In a second study, people who got Wegovy lost about 10% more weight than those who did not get Wegovy.
- In a third study, people who got Wegovy lost about 6% more weight than those who did not get Wegovy.
In addition, more people who got Wegovy lost 5% or more of their weight than those who did not:
- In one study, 86% of the people who got Wegovy lost 5% or more of their weight, compared to 32% who did not get Wegovy.
- In a second study, 69% of the people who got Wegovy lost 5% or more of their weight, compared to 29% who did not get Wegovy.
- In a third study, 87% of the people who got Wegovy lost 5% or more of their weight, compared to 48% who did not get Wegovy.
Adolescents
In the adolescent study, people who got Wegovy lost 17% more in BMI than those who did not get Wegovy. In addition, 73% of the people who got Wegovy lost 5% or more of their weight compared to 18% of those who did not.
Heart studies
Among people who took their regular heart medicines, had a healthy diet, and were physically active, those who got Wegovy had a much lower risk (about 20% less) of having a first major heart or blood vessel problem than those who followed the same diet and exercise routine without getting Wegovy.
What Are the Serious Side Effects of Wegovy, and How Can I Prevent or Manage Them?
In addition to common side effects, Wegovy may cause serious side effects:
- Risk of thyroid cancer. Inform your doctor if you notice a lump or swelling in your neck, have raspy or low voice (hoarseness), trouble swallowing, or shortness of breath. These could be the symptoms of thyroid cancer. In studies done on animals, Wegovy has caused thyroid tumors and cancers, but it is not known if it could have the same effect in people.
Do not use Wegovy if you or anyone in your family has a history of a type of thyroid cancer called medullary thyroid carcinoma, or if you have multiple endocrine neoplasia syndrome type 2 (MEN 2).
These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
How Do I Know if Wegovy Is Working?
You may start noticing changes in your weight after a few weeks. Your doctor will check your progress during regular visits and may change your dose of Wegovy to suit your individual needs. Do not change your dose or stop Wegovy unless your health care provider tells you.
How Do Other Medicines Interact With Wegovy?
Tell your health care provider and pharmacist about all the other prescription and over-the-counter medicines, vitamins, supplements, and herbal products you take. Wegovy lowers your blood sugar. It can also affect how some other medicines work in your body.
Insulin or medicines that raise insulin levels in the body: These medicines lower blood sugar. Examples include chlorpropamide, glimepiride, glipizide, glyburide, nateglinide, repaglinide, tolazamide, and tolbutamide. When your doctor starts you on Wegovy, they may adjust the dose of these medicines to help prevent blood sugar from dropping too much (hypoglycemia).
Medicines taken by mouth: Wegovy slows down the movement of your stomach. As a result, Wegovy may change how oral medicines (medicines that you swallow) work when you take them at the same time or close to when you get Wegovy. Your doctor will monitor you closely and advise you on how to best handle this.
How Can I Get Wegovy?
You will need a prescription for Wegovy from a health care provider, and you can get it at any pharmacy.
If you need assistance paying for Wegovy and your commercial insurance covers Wegovy, you may be eligible for a savings offer from the manufacturer. The manufacturer also has a free personalized support program called ‘WeGO Together’ which offers tools to help keep you on track with Wegovy and your treatment goals. To check your insurance coverage for Wegovy and learn more about the available support programs, visit www.wegovy.com/coverage-and-savings/save-on-wegovy.html.
