Semaglutide is an anti-diabetic medication used for the treatment of type 2 diabetes, and an anti-obesity medication used for long-term weight management and to reduce the risk of major adverse cardiovascular events. It is a peptide similar to the hormone glucagon-like peptide-1 (GLP-1), modified with a side chain. It can be administered by subcutaneous injection or taken orally. It is sold by Novo Nordisk under the brand names Ozempic and Rybelsus for diabetes, and under the brand name Wegovy for weight management, weight loss, and the treatment of metabolic-associated steatohepatitis (nonalcoholic steatohepatitis).
Semaglutide is an incretin mimetic. The most common side effects include nausea, vomiting, diarrhea, abdominal pain, and constipation.
It was approved for medical use in the US in 2017. In 2023, it was the nineteenth most commonly prescribed medication in the United States, with more than 25 million prescriptions. It is on the World Health Organization's List of Essential Medicines.


== Medical uses ==


=== United States ===
In the US, semaglutide is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes, and to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes and established cardiovascular disease.
In combination with a reduced calorie diet and increased physical activity, semaglutide (as Wegovy) is indicated to reduce the risk of major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) in adults with established cardiovascular disease and who are either obese or overweight; to reduce excess body weight and maintain weight reduction long term in obese individuals twelve years of age or older, or for overweight adults with at least one weight-related comorbid condition. After stopping semaglutide, individuals on average regain about two-thirds (67%) of the weight they lost during treatment within the following year. People return to their previous weight within a year and a half on average after stopping semaglutide.
In August 2025, the Food and Drug Administration (FDA) expanded the indication for semaglutide (as Wegovy) to include the treatment of noncirrhotic metabolic-associated steatohepatitis (MASH), formerly known as nonalcoholic steatohepatitis (NASH), with moderate to advanced liver fibrosis (consistent with stages F2 to F3 fibrosis) in adults.
In October 2025, the FDA further expanded the indication for semaglutide (as Rybelsus) to reduce the risk of major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) in adults with type 2 diabetes who are at high risk for these events.
In December 2025, the FDA approved an oral version of semaglutide for weight management, using the same brand name (Wegovy) as the injectable version.


=== European Union ===
In the European Union, semaglutide is indicated for the treatment of adults with insufficiently controlled type 2 diabetes as an adjunct to diet and exercise as monotherapy when metformin is considered inappropriate due to intolerance or contraindications, in addition to other medicinal products for the treatment of diabetes.
Semaglutide (as Wegovy) is further indicated as an adjunct to a reduced-calorie diet and increased physical activity for weight management, including weight loss and weight maintenance, in adults with obesity (initial BMI ≥ 30 kg/m2) or who are overweight (initial BMI ≥ 27 kg/m2) and have at least one weight-related comorbidity such as dysglycemia (prediabetes or type 2 diabetes), hypertension, dyslipidemia, or cardiovascular disease. It is also indicated as an adjunct to a reduced-calorie diet and increased physical activity for weight management in adolescents (aged twelve years and older) with obesity and body weight above 60 kg (130 lb).


== Side effects ==
Possible adverse effects include nausea, diarrhea, vomiting, constipation, abdominal pain, headache, fatigue, indigestion/heartburn, dizziness, abdominal distension, belching, hypoglycemia (low blood glucose) in people with type 2 diabetes, flatulence, gastroenteritis, and gastroesophageal reflux disease (GERD). It has in the past been suspected to cause pancreatitis, and can cause gastroparesis and bowel obstruction. Among people who were prescribed a glucagon-like peptide-1 (GLP-1) medication, 0.1% were diagnosed with gastroparesis at least six months later, which equates to a 52% increased risk of being diagnosed with gastroparesis while on a GLP-1 medication. A 2019 meta-analysis did not indicate a significantly elevated risk of acute pancreatitis.
The US prescription label for semaglutide contains a boxed warning for thyroid C-cell tumors in rodents. It is unknown whether semaglutide causes thyroid C-cell tumors, including medullary thyroid carcinoma, in humans.
In January 2026, the US Food and Drug Administration requested removal of suicidal behavior and ideation warning from glucagon-like peptide-1 receptor agonist (GLP-1 RA) medications.


== Contraindications ==
Semaglutide is contraindicated in people with a personal or family history of medullary thyroid carcinoma or in people with multiple endocrine neoplasia type 2.


== Mechanism of action ==

Semaglutide is a glucagon-like peptide-1 receptor agonist. The drug decreases blood sugar levels. The decrease is theorized to be caused by the mimicking of glucagon-like peptide-1 (GLP-1), an incretin. It also appears to enhance growth of pancreatic beta cells, which are responsible for insulin production and release. Additionally, it inhibits the production of glucagon, the hormone that increases glycogenolysis (release of stored carbohydrate from the liver) and gluconeogenesis (synthesis of new glucose). It reduces food intake by lowering appetite and slowing down digestion in the stomach, helping reduce body weight.


== Structure and pharmacology ==