How does semaglutide work for weight loss?

You will lose weight over the long-term with semaglutide because you will eat less, and feel fuller when you do eat. Semaglutide does this by targeting an area in the brain (called GLP-1 receptors) that help to regulate your appetite and how much you eat. It closely mimics a natural hormone in the body called incretin, which is made primarily in our digestive tract.

Semaglutide is used as a long-term weight loss treatment in addition to a healthy diet and exercise to help promote weight loss. Semaglutide (Wegovy and Ozempic) are also approved to help protect the heart in patients with heart disease.

In addition, Ozempic is approved is as treatment for type 2 diabetes to control blood sugar (glucose) levels and to reduce the risk of worsening kidney disease, kidney failure (end-stage kidney disease) and cardiovascular death in adults with type 2 diabetes and chronic kidney disease.

What is the mechanism of action of semaglutide?

Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist and occupies the GLP-1 receptor in the brain that regulates appetite.

It should not be used with other semaglutide-containing products (such as Ozempic, Rybelsus) or other GLP-1 receptor agonist medicines.

Semaglutide helps people to lose weight by:

• Targeting the brain centers that regulate appetite, especially after eating, which may help you eat less.
• Slowing down how quickly food leaves your stomach, which makes you feel fuller for longer.
• It's long-term effects. Semaglutide treatment is recommended for long-term use if it’s effective for you. With continued use, semaglutide has been shown in studies to help people lose about 15% of their weight (about 35 lb on average) and keep it off for over two years.

Who can use semaglutide for weight loss?

Semaglutide (Wegovy) is used, in addition to a low-calorie diet and increased physical exercise:

• for adults and children aged 12 years and older with obesity, or some
  adults with excess weight (overweight) who also have weight-related medical
  problems to lose weight and keep the weight off.
• to reduce the risk of major cardiovascular events such as death, heart attack, or stroke in adults with known heart disease and with either obesity or overweight.

Other prescription drugs that also contain semaglutide are Ozempic (injection) or Rybelsus (oral tablets). These brands are not specifically approved for weight loss, but can lead to weight loss when used for their indications.

Related questions

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• Tirzepatide vs semaglutide: How do they compare?

How long does semaglutide take to work?

You may see some weight loss in the 4 weeks of semaglutide treatment, but the full effect can take several months. After 68 weeks, adults lost an average of about 35 lbs (15.9 kg), or 15% of their weight, and these results were sustained at 2 years.

Your doctor will slowly increase your dose when you start treatment to help lessen stomach side effects like nausea and diarrhea. It typically takes about 17 weeks to reach your final maintenance dose of semaglutide.

• Studies conducted by the manufacturer over 68 weeks show that, on average, adults using semaglutide lost about 35 lbs (15.9 kg), or about 15% of their body weight. In contrast, 31% of people using a placebo (inactive treatment) lost about 6 lbs (2.7 kg), or about 2.5% of their body weight.
• In studies extended to 2 years (104 weeks), patients taking semaglutide (Wegovy) achieved about a 35 lb weight reduction vs. a 6 lb weight loss (15% vs. 2.6%) in people using the placebo (an injection with no medicine).
• In children 12 years and older, semaglutide reduced their body mass index (BMI) by 16.1% after 68 weeks compared to a 0.6% reduction in the placebo group. Plus, the BMI was reduced by at least 5% in 77% of children receiving semaglutide compared to 20% receiving a placebo.

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