How long does Wegovy take to work?

Weight loss doesn’t happen overnight—even if you’re taking a GLP-1 weight-loss medication like Wegovy. That said, you might start to notice a difference pretty soon after you start the medication. Here’s how it all happens.
Published May 10, 2024
How Long Does It Take for Wegovy to WorkHow Long Does It Take for Wegovy to Work

This content is for informational purposes only and does not constitute medical advice, diagnosis or treatment. It should not be regarded as a substitute for guidance from your healthcare provider.

Instant gratification seems to be the status quo these days, with everything from entire seasons of TV shows to groceries available on demand. That’s also how it can seem with FDA-approved GLP-1s—the newest kind of weight-loss medications that significantly reduce your appetite and slow digestion. But do these medications really deliver huge results in the blink of an eye? Here are the differences in your body that you may start to notice within a few weeks of starting a GLP-1 weight-loss medication like Wegovy— and what the journey is really likely to look like.

What is Wegovy and how does it work?


Wegovy is a brand name for the medication semaglutide, which has FDA-approval for weight loss. Semaglutide is one of several GLP-1 agonists approved for weight loss — others are liraglutide (Saxenda) and tirzepatide (Zepbound). These drugs all mimic GLP-1, short for glucagon-like peptide 1, which is a hormone that your body naturally produces when you eat food. It signals to your pancreas to release insulin, which helps control blood sugar, and reduces your appetite so you know when to stop eating, says Dr. Holly Lofton, M.D., professor of medicine and surgery at NYU Grossman School of Medicine and the director of the Medical Weight Management Program at NYU Langone Health in New York City.


It’s that appetite reduction that’s a big reason GLP-1 agonists lead to weight loss. On top of that, GLP-1 weight-loss medications also slow the rate at which the stomach empties and helps your body respond better to insulin, which keeps blood sugar levels low, further reduces appetite, and can help the body burn fat, Lofton says.


The health benefits of GLP-1 weight-loss medications like semaglutide go beyond helping you lose weight. “These include improved kidney function, cardiac risk reduction, and reduced inflammation in the body,” says Dr. Robert Kushner, M.D., professor of medicine and medical education at Northwestern University Feinberg School of Medicine in Chicago. Research has found that GLP-1 agonists like semaglutide can even reduce the incidence of major cardiac events, like strokes and heart attacks, by 20%.

How fast can you lose weight on Wegovy?


While the total amount of weight you can lose on semaglutide is pretty significant — studies show people can lose an average of 15 percent of their weight after a little more than a year — it doesn’t all happen at once.


When you first start Wegovy, your provider will monitor you at intervals (either every month or every six weeks) for the first 20 weeks and slowly increase your dose as long as you’re not experiencing severe side effects, says Lofton. You will work your way from 0.25 mg a week up to 2.4 mg a week, which is the maximum dose. And you’ll start to feel some changes immediately. “On average, patients experience a reduction in appetite once the medication is started,” says Kushner.


That downturn in hunger kicks off the weight loss. Anecdotally speaking, “most patients start to see some weight loss results in the first two months,” says Lofton. And it is pretty significant: Studies show that the average person will lose around 5 percent of their weight after three months. After six months, the average is 11 percent weight loss, and after 68 weeks, or around a year and 3 months, you hit the 15% number. It doesn’t always stop there, either. In one study, after two years on semaglutide, a third of people had dropped 20% or more of their starting weight.


This timeline won’t be true for everyone, however. How fast you lose weight can depend on “how well the individual receptors in the brain and stomach bind to the semaglutide,” says Lofton. And your pace may be slower if you take longer to go up in doses. (No, you can’t just start with the highest possible dose off the bat, since that may worsen its side effects, according to Kushner.)



What to consider before going on a GLP-1 weight-loss medication


As long as you meet the medical criteria, which is having a BMI above 30 or having a BMI of 27 as well as a weight-related health condition like high blood pressure, you can be a candidate for a GLP-1 like Wegovy. But there are some things to know beforehand. For one thing, the medication comes with potential side effects, including nausea, vomiting, diarrhea, constipation, and abdominal pain. They tend to be gastrointestinal in nature, since that’s where the medication is primarily working, and are usually temporary, says Kushner. For a complete list of side effects, please visit the Wegovy website here.


Side effects do tend to be more intense right after the weekly shot and whenever your dose goes up, so after you settle in at your final dose level, “the side effects may dissipate or linger at a lower and more tolerable level,” Kushner says. If your side effects make it tough to continue, your provider may be able to adjust your dosing to try to minimize them, says Lofton.


Also worth keeping in mind: Wegovy, like other GLP-1s, isn't a one-and-done drug that you stop taking once you lose weight. Instead, it's a long-term medication that your provider may recommend you stay on in order to maintain your results. In other words: It’s a commitment.



apricots grilled halves with yogurt and honey
apricots grilled halves with yogurt and honey

How to maximize your weight loss with Wegovy


While GLP-1s like semaglutide make a big difference in weight loss, they won’t lead to true weight health, or optimizing your well-being and quality of life, without some lifestyle changes as well. And bonus: Healthier habits like prioritizing nutritious foods and getting enough exercise can also help manage side effects alongside maximizing weight loss. “The cornerstone of obesity management is adopting and maintaining a healthy lifestyle, regardless of whether medications are prescribed,” says Kushner.


A program like WeightWatchers' new comprehensive GLP-1 program can help you stay focused on sticking with those lifestyle changes. You’ll be able to track activity, protein, fruits and veggies, and hydration and be part of a community of others going through the same journey you are. By prioritizing foods high in nutrients and drinking plenty of water, Kushner says you can reduce your risk for constipation and ensure you’re getting enough fiber and protein, even with a lower appetite.


Moving your body, like going for a walk and lifting weights, is also key when taking a GLP-1. “Physical activity and exercise are important to maintain muscle mass and for increased cardiorespiratory fitness,” Kushner says. Plus, if you’re creating an additional calorie deficit by taking an extra walk during your day on top of using the medication, you may lose weight more quickly, says Kushner.

Explore medical weight loss with WeightWatchers Clinic

Losing weight with a GLP-1 can be both exciting and confusing, and having the right care team in place can make all the difference. The new WeightWatchers Clinic offers comprehensive medical weight loss — teaming you up with board-certified doctors, registered dietitians, fitness coaches, and more to support your weight-loss journey. After answering a few questions, meeting with your provider, and sharing details on your medical history, biology, and insurance coverage, your care team can help you choose medication, if appropriate, be it semaglutide (Wegovy), liraglutide (Saxenda), tirzepatide (Zepbound), or something else.

Bottom line


When you first start taking a GLP-1 weight-loss medication like Wegovy, you may start to notice a difference in your appetite within a few weeks. After that, you can start losing weight quickly (up to 5 percent after three months), but it will still likely take more than a year for you to hit your final weight. Along the way, it’s key to pair the medication with lifestyle changes, like eating nutrient-dense food and being physically active most days. This ensures you’ll maximize your health benefits while on your weight-loss journey.