How does Ozempic work for weight loss?

Medical science seems to be constantly uncovering new potential uses for Ozempic®: Not only is it a game-changer for type 2 diabetes and, famously, weight loss, but it’s now being studied as a possible treatment for polycystic ovary syndrome, addiction, osteoarthritis, Alzheimer’s, Parkinson’s, sleep apnea, and non-alcoholic fatty liver disease. So, exactly how does Ozempic work for weight loss?

What is Ozempic? 

Ozempic, known generically as semaglutide, was actually approved by the U.S. Food & Drug Administration (FDA) to treat type 2 diabetes. However, during clinical trials, researchers discovered that in addition to lowering blood sugar levels and helping to regulate insulin, Ozempic also promoted weight loss. Since its approval in 2017, clinicians have prescribed the diabetes drug off-label to help those with excess weight and obesity, leading to increased demand and shortages. 

How does Ozempic work? 

As a member of the drug class known as GLP-1 receptor agonists, Ozempic works by mimicking the actions of glucagon-like peptide-1 (GLP-1), a hormone that your body naturally produces in response to eating. This hormone, released in the gut, slows the movement of food out of the stomach, reducing appetite and promoting a feeling of fullness. GLP-1 plays a crucial role in managing blood sugar levels by triggering the release of insulin to regulate blood sugar and working with the liver to keep it from producing and releasing too much sugar into the blood.

When Ozempic mimics GLP-1, it activates the same cell receptors as the hormone and causes the same responses in the body. That means it stabilizes blood sugar levels, helps to regulate insulin release, and slows gastric emptying, keeping you fuller, longer. It can also reduce cravings and suppress appetite, promoting weight loss.

How do you take Ozempic? 

Ozempic comes in disposable, prefilled, multi-dose pens with 4-6 doses. The manufacturer typically recommends a starting dose of 0.25 mg of Ozempic once a week for the first four weeks. This gradual approach gives your body time to adjust to the medication, which can help minimize the drug’s side effects (more on those later). A provider may gradually increase the weekly dose, as clinically indicated, to a maximum of 2 mg as patients continue to tolerate the drug. Prescriptions are up to a medical provider’s discretion; follow your provider’s instructions for taking Ozempic if they prescribe it.

To take Ozempic, patients give themselves an injection under the skin of the upper arm, stomach, or thigh, changing the injection site with each dose. Store the pens in the fridge with the caps on; when empty, place them in an FDA-cleared sharps disposal container or a heavy-duty plastic container with a tight-fitting lid (many people use a laundry detergent bottle). 

How fast does Ozempic work for weight loss? 

How quickly someone sees weight loss results when taking Ozempic varies from person to person. Most clinicians agree that losing one to two pounds each week is a healthy pace to shed weight and maintain the loss. For those taking Ozempic, weight loss is typically seen after eight weeks on the drug or shortly after the weekly dose has been increased to 0.50 mg. Keep in mind that everyone’s experience of healthy, medically assisted weight loss is unique and depends on family history, genes, lifestyle, sleep, and other factors. 

In one clinical trial of semaglutide, patients with type 2 diabetes who took a weekly dose of 0.50 mg of Ozempic lost an average of about 8 lb. during the 30-week trial. (The average starting weight for participants in the trial was about 202 pounds.) In a second study, patients with type 2 diabetes on a weekly dose of 1 mg of Ozempic lost an average of 13 pounds during the 40-week trial. For those taking 2 mg of Ozempic each week, the weight loss increased to an average of 15 pounds.

What are the side effects of Ozempic? 

While many people do not experience any side effects, they are possible. The most common side effects of Ozempic are: 

• Nausea
• Diarrhea
• Constipation
• Vomiting
• Abdominal pain 
• Headache 
• Indigestion
• Dizziness
• Back pain
• Bloating 
• Belching
• Fatigue
• Injection site reactions
• Upset stomach 

These side effects are typically most common during the first four weeks on Ozempic. As the body adjusts to the medication, side effects often subside. However, if they persist, it’s important to talk with your doctor. 

Is it safe to take Ozempic for weight loss? 

Although Ozempic is FDA-approved for type 2 diabetes, clinicians also prescribe the drug off-label for safe and effective weight loss. However, semaglutide, Ozempic’s active ingredient, is also available under the brand name Wegovy®. In 2021, the FDA approved Wegovy for weight loss in those with obesity—a body mass index (BMI) of 30+—or with excess weight (a BMI of 27+) and at least one weight-related health condition like high blood pressure or high cholesterol. In March 2024, the FDA approved Wegovy to reduce the risk of cardiovascular death, heart attacks, and strokes among adults with obesity or overweight and cardiovascular disease. 

The difference between these two brand-name drugs is slight: it’s the amount of semaglutide they contain at their highest doses. Specifically, Ozempic has a slightly lower amount at its highest dose than Wegovy (2 mg vs 2.4 mg).  

What are the risks of taking Ozempic? 

While Ozempic and Wegovy are safe and effective for weight loss, they are not suitable for everyone. Although rare, in animal studies, semaglutide caused thyroid C-cell tumors. Ozempic’s “black box” warns of the risk of these tumors. If you have trouble swallowing, develop hoarseness, or feel swelling or a lump in your neck, contact your Found health care provider immediately. 

The FDA also warns not to take Ozempic if you have a personal or family history of multiple endocrine neoplasia syndrome type 2 or medullary thyroid cancer. Ozempic is not used to treat insulin-dependent diabetes or diabetic ketoacidosis. So, if that’s you, Ozempic isn’t the right fit. Wegovy has the same side effects and risks. Find detailed side effect and risk information for both Ozempic and Wegovy on our dedicated medication page.

Will I regain weight if I stop using Ozempic? 

When patients stop using Ozempic, they no longer have the drug’s assistance in reducing cravings, suppressing appetite, or slowing gastric emptying to feel fuller for longer. In one study, a year after they stopped taking Ozempic participants had regained up to two-thirds of their lost weight. Weight loss and maintenance can be complicated, and continued success may require long-term use of Ozempic.

Should I use Ozempic for weight loss?

Ozempic isn’t a weight-loss aid for everyone and isn’t for those looking to lose ten pounds quickly for the summer. The drug benefits people who have excess weight or obesity. Specifically, someone with: 

• A BMI of 30+ 
• A BMI of 27+ and a chronic health condition that can improve with weight loss 

Use our BMI calculator to check yours.

While Ozempic can help many people lose weight, it’s not the right choice for everyone. You should not take Ozempic if you have any of the following: 

• Kidney disease
• Gallstones or active gallstone disease
• Pancreatitis 
• Medullary thyroid cancer or a family history of this type of cancer
• Multiple endocrine neoplasia type II (MEN2) syndrome or a family history of MEN2

Talk to your health care provider to determine if Ozempic is a good fit for you. Deciding if Ozempic—or another weight loss drug—is appropriate is a big decision. Found-affiliated health care providers are trained in obesity medicine. They use our proprietary MetabolicPrint™ analysis to determine and target the root causes of your weight gain. After evaluating how your metabolism affects your weight, your Found provider will tailor a medically appropriate weight management program just for you. 

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About Found

Found is among the largest medically-supported telehealth weight care clinics in the country, having served 250,000 members to date. To discover your MetabolicPrint™ and start your journey with Found, take our quiz. 

While GLP-1s are effective for weight loss, they are not clinically appropriate for everyone. Eligibility for a GLP-1 is based on a thorough evaluation of your medical history, eating behavior, lab work, and insurance coverage. If a GLP-1 is not appropriate for you, our providers will work with you to determine an effective medication for your health profile. This content does not provide medical advice and does not substitute for a consultation with a doctor or healthcare provider.