Not losing weight on Ozempic? Doctors explain what might be happening and what to do next

You’ve done everything exactly as you were told. You filled the prescription, learned to do the injection without flinching and white-knuckled your way through the days when you couldn’t look at food without feeling queasy. Now several weeks have gone by, yet the number on the scale is stubbornly right where it started. 

Meanwhile, your BFF is two dress sizes down, your brother-in-law won’t stop talking about his freshly emerging abs and every ad, talk show and group chat tells you that GLP-1 drugs are effortless. Your experience begs to differ, and you’re not alone. Even in the landmark 2021 STEP 1 trial that made these medications famous, nearly 14% of people on semaglutide lost less than 5% of their starting weight after more than a year.

So what’s going on? We asked Dr. Nisha Patel, an obesity medicine physician, and Dr. Gillian Goddard, a board-certified endocrinologist and adjunct assistant professor of medicine at NYU Grossman School of Medicine, to walk us through the most likely culprits. Here are nine reasons you might not be losing weight.

1. Your dose isn’t where it needs to be yet

The first thing Patel and Goddard said they check? The dose.

With semaglutide, sold as Ozempic and Wegovy, doses start low and increase no sooner than every four weeks. The gradual increase is designed to keep side effects like nausea manageable, not to speed up weight loss. 

“Weight loss is typically dose-dependent with GLP-1 drugs,” says Patel. That means your stall might be a dose problem rather than a drug problem. “We typically don’t think of someone as a non-responder to GLP-1 until they are on the highest tolerated dose for at least three months,” she says. “I have had patients where it wasn’t until the very highest dose that they started to experience weight loss.”

Your maximum dose depends on which version you’re on. Ozempic, approved for type 2 diabetes, has a maximum recommended dose of 2 mg once weekly, and you won’t get there before week 13. Wegovy, approved for weight management, has a recommended maintenance dose of 2.4 mg once weekly, reached at week 17 at the earliest. Since March 2026, adults who tolerate 2.4 mg and need more weight loss can step up to a 7.2 mg dose, sold as Wegovy HD.

Because it takes months to get to a maximum dose, plenty of people are still mid-schedule when they start wondering what’s up.

2. You haven’t changed your lifestyle

The biggest misconception, according to Goddard, is that weight loss will be effortless. These drugs “aren’t magic,” she says. “GLP-1s like semaglutide really need to be paired with diet and exercise to get the best benefit.” 

The Food and Drug Administration agrees. FDA approval of these drugs is for use alongside a reduced-calorie diet and increased physical activity, and the landmark trial followed that to the letter. Everyone in it was instructed to have a 500-calorie daily deficit and do 150 minutes of exercise a week, with sessions every four weeks to keep them on track. In other words, the results show what the combination does, not what the injection does on its own.

No GLP-1 removes these requirements, and if you eat more than you burn, you likely won’t see the results you want.

3. Your body composition is shifting

It’s easy to forget that the number on the scale isn’t just fat. It also reflects muscle, bone and fluid, so losing fat and losing weight aren’t the same thing. If you hold on to muscle while the fat goes away, the scale moves less than you’d expect. Patel says that’s typical in people who are exercising, lifting weights and getting enough protein alongside the medication.

That’s why she’d rather you measure body composition, not just weight. The easiest route is bioimpedance, which estimates your fat and muscle using a small electrical current. Gyms and clinics have professional machines, but a smart scale can give you a rough estimate at home. At-home versions won’t match the precision you can get at a clinic, so don’t get too attached to the exact numbers, but they can show you trends.

For a more accurate read, there are DEXA scans, which use a low-dose X-ray to assess fat mass from muscle and bone. You’ll find them at universities, imaging centers and some gyms.

4. You’re expecting the wrong number

Picture what success on semaglutide looks like, and you’ll probably imagine something dramatic, like needing a completely new wardrobe by month two. “Patients often expect to lose weight overnight,” Goddard says. Instead, she recommends aiming for 1 to 2 pounds a week, or slightly more at the start. Dropping weight too quickly raises your risk of gallstones, so she says she’d rather take the scenic route.

You’re probably also braced for steady losses, which makes a plateau feel like failure. Goddard says the rate of loss shifts from week to week, and what counts is the trend over time, not any individual weigh-in.

5. Your appetite is still in charge

Early on, appetite suppression does the heavy lifting. You eat less of everything without deciding to, and Goddard says that at that stage, you can eat a little of almost anything and still see your weight go down.

Then, the appetite suppression fades. Or, if you’re still working up to your full dose, it may never have kicked in with much force in the first place. Either way, you’re left doing the job the medication was doing for you, which means paying attention to what you eat.

Goddard’s advice is to choose foods that fill you up without a heavy calorie load. In practice, that means protein, fiber and vegetables. Portion size counts too, she says.

6. Your hormones are working against you

Goddard notes that menopause and poorly-controlled thyroid disease can each make weight loss harder, though in different ways.

During menopause, hormonal shifts change how your body handles insulin and blood sugar. Falling estrogen is linked to increased insulin resistance and belly fat, and your metabolic rate may dip slightly too. These changes can begin during perimenopause, which lasts for several years, so this isn’t just a post-menopause problem.

Thyroid disease works differently. An underactive thyroid slows your metabolic rate, so you burn fewer calories at rest. Anyone can develop it, but it’s more common in women, particularly after menopause. If you’re on top of your diagnosis, it won’t be the culprit, but if you haven’t had your thyroid checked in a while, ask your doctor to test your levels. 

None of this means the drug won’t work for you. You’ll just need to game plan with your doctor to figure out what your body needs.

7. You’re not sleeping

Skimping on shut-eye sets off a chain reaction. “Poor sleep leads to higher cortisol levels,” Goddard says. “High cortisol levels cause increased insulin resistance, which then can lead to weight gain or, in this case, reduced weight loss.”

The research agrees. A 2026 review of 30 studies covering nearly 11,000 people found that sleep restriction appears to blunt fat loss during weight loss programs. In another randomized trial, researchers took 80 adults aged 21 to 40 who slept under 6.5 hours a night and gave them an individualized sleep-coaching session. They gained an average of 1.2 hours of sleep per night and, without any diet advice, ate 270 fewer calories a day than the control group. 

“Studies suggest improving sleep can improve weight loss,” Goddard says, and she thinks it’s worth the effort. Even if endless scrolling is calling, try to get to bed at a reasonable hour to optimize your weight loss efforts. 

8. Your other medications are working against you 

Some drugs cause weight gain in their own right, and if you’re taking one, it may be working against what your GLP-1 drug is supposed to be doing. Goddard names antipsychotics like Seroquel as an example, and says medications of that kind can reduce how well a GLP-1 works. 

Certain antidepressants, steroids, beta blockers and some diabetes medications can also cause weight gain, as can insulin, gabapentin and antihistamines. Whether any of them blunts a GLP-1 specifically is less clear, but a drug that adds weight is working against one that takes it off. 

However, it’s important you don’t stop taking any prescription meds on your own. Bring a list of everything you take to your next doctor’s appointment and ask whether there are suitable alternatives. 

9. You might be a non-responder

For a small group of people, these meds simply don’t land the way they do for everyone else, and good habits don’t change that. 

Goddard thinks genetics play a large role, and she singles out the gene for the GLP-1 receptor itself, the exact target that semaglutide acts on. Research points in the same direction. A 2026 study of nearly 28,000 people on GLP-1s found a variant in that gene was linked to how much weight people lost, though any single variant’s effect is small. 

The frustrating part is that you can’t know in advance. “Right now we don’t know how to identify people who won’t respond to GLP-1s before they start,” Goddard says. But not responding to semaglutide doesn’t mean you won’t respond to anything. Tirzepatide, sold as Mounjaro and Zepbound, targets a second receptor in addition to GLP-1, and Goddard says it may still work for non-responders. 

What to do if your weight isn’t going down

Before you decide your GLP-1 has failed you, work through this checklist:

• Verify injection basics. Are you injecting on the same day every week, and storing the pen correctly? Patel checks dosing consistency first because it’s the quickest thing to adjust.  
• Check your expectations on timing. For Patel, the clock starts when you reach your highest tolerated dose, not when you took your first injection. She gives it three months from that point. 
• Get a baseline measurement. A DEXA or bioimpedance reading of your body composition gives you something to compare against later. Without it, you’re relying on a scale that can’t tell fat mass from muscle mass.
• Hit the weights twice a week. Resistance training combined with adequate protein consumption helps protects muscle while you lose fat, and Patel recommends it for her patients.
• Book the appointment. “I typically recommend talking to your doctor if you’ve lost less than four pounds in a month,” says Goddard.
• Show up prepared. Take a list of every medication you’re on, how long you’ve been at your current GLP-1 dose and any questions you might have about thyroid levels or menopause status. Those are the details your doctor will need to help work out what’s going on.
• Ask what’s next. You might need to increase your dosage, switch to a different medication or have tests run to see if anything else is at play. If you’re maxed out on dose and you’re months in with nothing to show, switching meds is a legitimate conversation to have.

Weight loss isn’t the only measure of success

“I always tell patients that weight loss is only a part of the health improvements puzzle,” says Patel. Even when the scale doesn’t move, you may see your blood sugar, cholesterol and liver health head in the right direction. “We need to celebrate all of the wins,” she says. Before you write off your progress, consider what else might have shifted, from your blood pressure to how your knees feel on the stairs or whether you sleep through the night now. 

And if you’re still measuring yourself against your neighbor, stop. “Rome wasn’t built in a day, and neither is your health,” Patel says. It’s easy to compare your journey to someone else’s, she adds, and much harder to accept that healthy weight loss is often slower than you’d expect.

Meet our experts

• Gillian Goddard, MD, a board-certified endocrinologist, adjunct assistant professor of medicine at NYU Grossman School of Medicine and author of The Hormone Loop
• Nisha Patel, MD, obesity medicine physician and medical director, Obesity and Metabolic Health at Sutter Health California Pacific Medical Center 

Our health content is for informational purposes only and is not intended as professional medical advice. Consult a medical professional on questions about your health.