Semaglutide for Weight Loss: Does it Work?

Semaglutide is no longer just a diabetes medication–many have benefited from its weight loss effects. But how does semaglutide work?

Chelsea Rae Bourgeois, MS, RD
— Signos
Health writer
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Updated by

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Science-based and reviewed

July 24, 2024
November 7, 2023
— Updated:

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Research has shown that obesity patterns are on the rise, with predictions suggesting that 50% of Americans will fall into the overweight or obese categories by 2030.1 Approved by the U.S. Food and Drug Administration in 2017, semaglutide continues to spark conversation in the search for safe and sustainable weight loss treatment.

Semaglutide is a once-weekly subcutaneous injectable drug that was initially designed as a diabetes medication and is now commonly used to treat chronic body weight management. Research indicates that semaglutide can support weight loss efforts, making it a curious option for those pursuing weight management. But how does semaglutide work? In this article, we’ll explain the science behind this trending drug, examining its mechanisms, implications, and safety.

What is Semaglutide?

Semaglutide is a glucagon-like peptide-1 receptor agonist, or GLP-1 RA. It mimics the GLP-1 hormone, which is released in the gut in response to food intake. GLP-1 receptor agonists prompt the body to make more insulin to reduce blood glucose levels, which is why many healthcare professionals have prescribed semaglutide injections as a treatment for type 2 diabetes for many years.

In simple terms, semaglutide helps improve insulin resistance, helping the body burn calories and fat while improving energy. It targets the area of the brain that controls appetite and regulates food intake. Through these mechanisms, semaglutide can help prevent blood sugar spikes and food cravings, resulting in a more balanced dietary intake. 

Semaglutide is available under three prominent brand names: Ozempic, Rybelsus, and Wegovy. However, Wegovy is the only semaglutide treatment that is FDA-approved as a weight loss medication. Ozempic and Rybelsus earned approval from the FDA to lower blood sugar levels in adults with type 2 diabetes.2

Semaglutide for Weight Loss


Semaglutide is a weekly injection administered in doses of 2.4 milligrams. While it originated as a diabetes medication, it can be used by people without diabetes under the care and guidance of their healthcare provider. So, how does semaglutide work for weight loss?

Semaglutide helps regulate appetite control and metabolism by sending signals to the brain, indicating satiety and delaying gastric emptying. By slowing down digestion, semaglutide prolongs feelings of fullness and reduces the likelihood of overeating. This helps users moderate their calorie intake and stay in a deficit.

Additionally, semaglutide aids in weight management by helping the body break down fat and use it more efficiently. Clinical trials have shown a 5 to 15% reduction in body weight when taking weekly semaglutide injections for 68 weeks. Those in the control groups lost significantly more weight than those in the placebo group.3 

Of course, these results focus on the long-term use of the weight loss drug and do not account for stopping the medication. Many experts warn of potential weight gain once the medication is stopped. 

Does Semaglutide Work for Weight Loss?

Semaglutide was not created to be a weight loss drug, but it has seen a lot of hype over recent years for its effects on weight. But can semaglutide injections support your weight loss journey?

Research has shown that semaglutide can increase weight loss by promoting satiety and increasing fat loss. You may notice weight loss within four weeks, but the medication’s full effects may take several months. Your doctor will likely start you on a conservative semaglutide dose for weight loss and slowly increase your dosage to avoid triggering gastrointestinal side effects.

More research is needed to better understand the medication’s long-term effects, but current studies indicate maintained weight loss over two years when semaglutide is taken consistently as prescribed.4 

However, it’s important to remember that semaglutide is not a magic fix, and all weight loss journeys are unique. Sustainable weight loss requires a holistic approach. Weight loss medications are designed to be administered alongside healthy lifestyle changes that promote well-balanced nutrition and regular exercise. Creating a calorie deficit through positive nutrition choices and consistent physical activity is essential to lose weight sustainably.

The current Physical Activity Guidelines for Americans recommend at least 150 minutes of moderate-intensity or 75 minutes of vigorous aerobic exercise each week. The guidelines also recommend at least two days of strength training for maximum health benefits.5 If you have questions about your nutritional intake, consider meeting with a registered dietitian nutritionist. 

Semaglutide Side effects

Like with any medication, semaglutide does not come without the risk of unwanted side effects.6 Originally prescribed as a diabetes medication, providers noticed weight loss as a side effect of the drug. However, not all side effects are welcomed similarly. 

Common side effects of semaglutide include:

  • Diarrhea
  • Constipation
  • Nausea
  • Vomiting
  • Decreased appetite
  • Stomach pain

However, semaglutide may cause more severe side effects that require immediate care from your healthcare provider. These may include:

  • Changes in vision
  • Dehydration
  • Heart palpitations
  • Gallbladder issues
  • Pancreatitis
  • Thyroid cancer
  • Allergic reactions
  • Hypoglycemia
  • Acute kidney injury
  • Thoughts of self-harm

If you experience unwanted side effects while taking a semaglutide injection, talk with your doctor to determine the best course of action.

Is Semaglutide Safe for Me to Take?


Semaglutide is typically considered safe for most adults, but it isn’t without its risks. All three brands of semaglutide require a prescription, and it is only administered for chronic weight management if the patient meets specific criteria. To qualify for a semaglutide prescription, patients must have a BMI of 30 kg/m2 or greater or a BMI of 27 kg/m2 and at least one weight-related comorbidity, such as high blood pressure or high cholesterol.7

Semaglutide should only be used when prescribed for approved medical purposes. After receiving the prescription, semaglutide users are tasked with injecting themselves weekly with the medication at home. If you are not comfortable administering injections, you will need to seek guidance from your healthcare provider.  

You should not take semaglutide if you have a history of medullary thyroid cancer, pancreatitis, gallbladder disease, or multiple endocrine neoplasia syndrome type 2. Furthermore, you should not take semaglutide if you are pregnant or trying to get pregnant, and if you are breastfeeding, talk with your doctor about potential risks before starting semaglutide. 

Additionally, semaglutide may not be appropriate for those taking insulin and other diabetes medications as it may affect blood sugar control.

This prescription medication should only be administered under a doctor's supervision to ensure it does not negatively impact your health. If you have questions about semaglutide interactions and its potential in your diabetes care or weight loss efforts, talk with your doctor. It’s essential to consider your medical history and how it affects your efforts to achieve your wellness goals.

Learn More About Healthy Habits and How to Improve Blood Sugar Health with Signos’ Expert Advice

Small changes can go a long way in managing diabetes and improving overall health. Choosing the right foods and monitoring blood sugar levels can help optimize your biological systems and set you up for success in wellness. 

Consuming a well-balanced diet of fruits, vegetables, lean proteins, whole grains, and healthy fats can ensure you meet your nutrient needs. Continuous glucose monitoring provides you with important data about your body’s response to those foods and how they affect your day-to-day health. Plus, Signos’ experts are well-equipped to help you navigate such valuable information and make adjustments to your lifestyle as needed.

Knowledge is power! Learn how Signos can improve health and more about nutrition and beneficial lifestyle habits on Signos’ blog. Curious if Signos is a good fit? Find out by taking a quick quiz!

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Topics discussed in this article:


  1. Wang Y, Beydoun MA, Min J, Xue H, Kaminsky LA, Cheskin LJ. Has the prevalence of overweight, obesity, and central obesity leveled off in the United States? Trends, patterns, disparities, and future projections for the obesity epidemic. Int J Epidemiol. 2020;49(3):810-823. doi:10.1093/ije/dyz273
  2. Research C for DE and. Medications containing semaglutide marketed for type 2 diabetes or weight loss. FDA. Published online October 10, 2023.
  3. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002.
  4. Garvey WT, Batterham RL, Bhatta M, et al. Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial. Nat Med. 2022;28(10):2083-2091. doi:10.1038/s41591-022-02026-4
  5. U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans, 2nd edition. Washington, DC: U.S. Department of Health and Human Services; 2018. 
  6. Smits MM, Van Raalte DH. Safety of Semaglutide [published correction appears in Front Endocrinol (Lausanne). 2021 Nov 10;12:786732]. Front Endocrinol (Lausanne). 2021;12:645563. Published 2021 Jul 7. doi:10.3389/fendo.2021.645563
  7. U.S. Food and Drug Administration. FDA approves new drug treatment for chronic weight management, first since 2014.

About the author

Chelsea Rae Bourgeois is a registered dietitian nutritionist with several years of experience working in the clinical setting. Once a track and field athlete on a competitive stage, she now finds joy in combining her passions as a health writer to help people embrace their wellness through nutrition and fitness.

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