How long does it take for semaglutide to work? Wegovy, Ozempic, and Rybelsus explained

Key Points

• Semaglutide reduces appetite within the first two weeks, with most people reaching steady levels by 4-5 weeks of treatment
• Weight loss averages 2% by four weeks and 4% by eight weeks, with clinical studies showing a 15% average loss over 68 weeks
• Blood sugar improvements occur gradually, with A1C reductions of 1.2%-2.2% seen between 26-40 weeks, depending on medication type
• The medication works best when paired with healthy eating habits and regular physical activity for optimal results

If you’re taking semaglutide for weight loss or diabetes, you’re probably wondering when you’ll start seeing results. While some people have been posting dramatic before-and-after weight loss pictures online, it helps to have realistic goals and expectations.

Most people notice changes in their appetite within the first two weeks of starting treatment. However, the timeline for significant results varies depending on whether your goal is weight loss or blood sugar control, with full benefits developing over several months of consistent use.

Semaglutide results are based on how the drug works, the dose, and lifestyle factors.

How does semaglutide work?

"Semaglutide mimics a natural hormone called GLP-1. This hormone regulates blood sugar, digestion, and appetite," explains Gia Eapen, MD. “Semaglutide helps release insulin when your blood sugar is high, slows down how fast food leaves your stomach, and reduces hunger signals sent to your brain.”

Semaglutide comes in two different forms: injections and pills. Each form has its own specific uses and approvals.

Injectable semaglutide

Injectable semaglutide is sold under two brand names with different FDA approvals:

• Wegovy is FDA-approved for chronic weight management in adults and children 12 years and older with obesity. It's also approved for reducing cardiovascular event risk in adults with cardiovascular disease who are overweight or obese.
• Ozempic is FDA-approved to treat type 2 diabetes. It can reduce the risk of major cardiovascular events in adults with type 2 diabetes and known heart disease.

Oral semaglutide

Rybelsus is the pill form of semaglutide. It is approved by the FDA to manage type 2 diabetes in adults. It is taken once daily and comes in 3 mg, 7 mg, and 14 mg doses.

How long does it take for semaglutide to work for weight loss?

"Typically, early effects such as appetite suppression begin within the first couple of weeks. More pronounced effects, like weight loss, can be seen in 4-5 weeks, although individual results vary," notes Eapen, MD.

How long does it take to lose weight on Wegovy?

Clinical studies show that participants experienced a mean weight loss of 15% over 68 weeks:

• In 4 weeks, participants experienced an average of 2% weight loss
• In 8 weeks, they experienced 4% weight loss

The good news is that most of the people in the study lost weight on Wegovy:

• Over 86% of participants lost at least 5% of their body weight
• About 70% lost 10% of their body weight or more

Note: The FDA has not approved Ozempic and Rybelsus for weight loss.

How long does it take for semaglutide to reduce A1C levels?

How long does it take for Ozempic to reduce A1C?

In a study, people on the 2 mg dose of Ozempic saw their A1C drop by an average of 2.2 points after 40 weeks (around 9 months). In those taking the 1.0 mg dose, the A1C dropped by 1.9 points in the same time period.

How long does it take for Rybelsus to lower A1C?

Studies found that taking 14 mg of oral semaglutide daily lowered A1C by 1.2% after 26 weeks.

“It’s important to know that blood sugar improvements happen gradually over weeks and months of consistent treatment,” explains Eapen, MD. "Consult your healthcare provider to learn more about what to expect.”

Semaglutide dosage

Wegovy dosage

Treatment with Wegovy begins with a starter dose of 0.25 mg injected once weekly for the first month.

Every four weeks, your healthcare professional will increase the dose until you reach your maintenance dose of either 1.7 mg or 2.4 mg once weekly.

This gradual increase of your semaglutide dose allows your body to adjust while reducing side effects.

Ozempic dosage

Ozempic treatment starts with 0.25 mg administered once weekly for the initial four weeks to help your body adjust. Around week 5, your dose may be increased to 0.5 mg once weekly. The maximum Ozempic dose is 2 mg once weekly.

Rybelsus dosage

Rybelsus comes in three doses: 3 mg, 7 mg, and 14 mg. Treatment starts with 3 mg taken daily for the first month.

After the initial month, the dosing increases to 7 mg daily for at least another four weeks.

If additional blood sugar control is needed, your doctor may prescribe the maximum daily dose of 14 mg.

"Your healthcare provider will determine the appropriate dosage for you based on how your blood sugar levels, how your body adjusts to the medication, and any side effects," notes Eapen, MD.

Importance of diet and exercise when on semaglutide

"It’s possible not to lose weight on semaglutide. The medication is most effective when combined with healthy lifestyle changes. Sustainable weight loss results and blood sugar control come from pairing it with nutritious eating and regular physical activity," explains Rita Faycurry, RD, Registered dietitian.

A registered dietitian can help you make the most of your semaglutide treatment by:

• Creating personalized meal plans that work with the medication's appetite-suppressing effects
• Teaching you to balance your plate, portion your food, understand serving sizes, and read nutrition labels
• Helping you develop healthy eating patterns that support long-term success.

Final thoughts: How long does semaglutide take to work?

Semaglutide can help in treating both diabetes and obesity. While results vary, substantial benefits are seen over weeks of consistent treatment.

Success requires patience and commitment to the prescribed dosing schedule. Additionally, lifestyle changes like proper nutrition and regular exercise play an important role.

Working closely with a registered dietitian can help you lose weight and control blood sugar levels with semaglutide.

Lose weight on semaglutide. Find a weight loss dietitian near you, covered by insurance.

Frequently asked questions (FAQs)

Does semaglutide suppress appetite immediately?

Eapen, MD, says, “Typically, most people notice that they feel less hungry within the first couple of weeks on semaglutide. Consult with your healthcare provider to understand what you can expect in your unique situation.”

How long does it take semaglutide to start working for weight loss?

In clinical trials, people experienced 2% weight loss in 4 weeks and 4% in 8 weeks. Overall, there was an average weight loss of 15% over 68 weeks.

Can I lose 20 lbs on semaglutide?

Clinical studies show participants experienced an average of 15% body weight reduction over 68 weeks. For someone weighing 200 pounds, this would represent nearly 30 pounds of weight loss. However, an average means that some people lost more weight, while others lost less.

Weight loss varies from person to person and also depends on lifestyle factors such as diet and exercise.

What happens in the first week on semaglutide?

During your first week on semaglutide, you may feel less hungry and feel full faster when you eat. Some people may have side effects like nausea, stomach upset, vomiting, diarrhea, and constipation. Typically, side effects get better as the body adjusts to the medication, but if they persist, please consult a healthcare provider.

Get a semaglutide diet plan made just for you , by a dietitian who accepts your insurance.

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.