Semaglutide For Weight Loss: How It Works And What To Expect

Semaglutide is one of the most popular treatments for chronic weight management. If you're thinking of trying this weight loss medication, learn how it works and how much weight it can help you lose, in this post. Our experts review the research so you can know exactly what you can expect from your treatment. 

What is semaglutide? 

Semaglutide is the active ingredient in medications originally developed to treat adults with type-2 diabetes. It's a type of drug known as a GLP-1 receptor agonist, which is a synthetic version of a naturally occurring hormone in your body: glucagon-like peptide 1. In 2021, the Food and Drug Administration (FDA) approved semaglutide for weight management in adults with obesity or other weight-related conditions, such as high blood pressure or high cholesterol. 

It's typically taken as a subcutaneous injection, meaning it's injected into the layer of fatty tissue just below your skin. You may have heard it marketed under well-known brand names such as Ozempic or Wegovy. 

How does semaglutide help with weight loss? 

Understanding GLP-1 

Glucagon-like peptide-1 (GLP-1) is a hormone that occurs naturally in your gut. It helps your body turn food into energy — but how?

To understand how GLP-1 works, you need to know about two key hormones in your body: insulin and glucagon. Insulin helps glucose, or sugar, in your blood enter your cells, where it's used for energy. This lowers your blood sugar levels. Glucagon has the opposite effect. It stimulates your liver to release stored glucose into your blood when your levels are low. Both hormones work together to regulate your blood sugar. 

GLP-1 helps regulate these two hormones. After you eat, GLP-1 is released from your intestines. It increases insulin and suppresses glucagon, which lowers your blood sugar levels after meals. 

Appetite regulation

One of the key ways semaglutide can help boost your weight loss results is by increasing feelings of fullness. It targets the appetite regulation center in your brain, reducing hunger and increasing satiety. [1] Semaglutide also slows gastric emptying, or the rate your food leaves your stomach after you eat it. [2] Because of these effects, many people who take semaglutide report a decreased desire to snack or overeat. [1] This makes it easier to stay in a calorie deficit — where you consume fewer calories than you use — which is essential for weight loss. 

Effect on blood sugar levels

Along with suppressing your appetite, semaglutide treatment also helps control your blood sugar. By mimicking the action of natural GLP-1 in your body, it improves insulin sensitivity and reduces the risk of blood sugar spikes after meals. [3] This helps curb food cravings and supports your overall metabolic health. 

Clinical trials and efficacy 

Research shows that semaglutide is an effective treatment that can help you boost your weight loss results. A landmark clinical trial known as the STEP study found that people who took semaglutide lost 15% of their body mass in 68 weeks, on average, compared to 2.4% in the placebo group. [4] Participants reported significant improvements not just in their weight, but also in their overall health, too. 

Results can vary based on many factors, however. We recommend combining a medical weight loss treatment with other manageable lifestyle changes, like eating a balanced diet and doing regular physical activity, to maximize your weight loss results. 

How long will weight loss results last? 

GLP-1 medications are designed for long-term weight management. We recommend you stay on your medication for at least six months until you reach your maintenance dose. Semaglutide has been shown to continue weight loss over a period of 68 weeks, and studies are ongoing into its long-term effects if you stop treatment. [5]

Does semaglutide have any side effects?

Like all medications, semaglutide can cause some common side effects. These include: nausea and vomiting, constipation, diarrhea, headaches and heartburn. To learn more, read our dedicated blog post. 

Is a semaglutide injection right for you?

Our prescribers can help. We'll assess your medical history and recommend the best treatment plan for your needs. Once you're approved for treatment, we'll check in regularly to monitor your progress, and help you through every step of your weight loss journey with expert health coaching. 

Start your online consultation today.

References:

1. Blundell J, Finlayson G, Axelsen M, Flint A, Gibbons C, Kvist T, et al. Effects of once‐weekly semaglutide on appetite, energy intake, control of eating, food preference and body weight in subjects with obesity. Diabetes, Obesity and Metabolism [Internet]. 2017 May 5;19(9):1242–51. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573908/ 

2. Silveira SQ, da Silva LM, de Campos Vieira Abib A, de Moura DTH, de Moura EGH, Santos LB, et al. Relationship between perioperative semaglutide use and residual gastric content: A retrospective analysis of patients undergoing elective upper endoscopy. Journal of Clinical Anesthesia [Internet]. 2023 Aug 1 [cited 2023 Mar 3];87:111091. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0952818023000417?dgcid=coauthor 

3. Garvey WT, Batterham RL, Bhatta M, Buscemi S, Christensen LN, Frias JP, et al. Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial. Nature Medicine [Internet]. 2022 Oct 1;28(10):2083–91. Available from: https://www.nature.com/articles/s41591-022-02026-4 

4. Wilding JPH, Batterham RL, Calanna S. Once-Weekly Semaglutide in Adults with Overweight or Obesity. The New England Journal of Medicine [Internet]. 2021 Feb 10;384(11):989–1002. Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2032183 

5. Ryan DH, Lingvay I, Deanfield J, Kahn SE, Barros E, Burguera B, et al. Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial. Nature Medicine [Internet]. 2024 May 13;30:1–9. Available from: https://www.nature.com/articles/s41591-024-02996-7