Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
If you’re on a weight loss journey or just very invested in TikTok health trends, chances are you’ve heard of semaglutide. Whether you know it by brand names like Ozempic or Wegovy, the buzz around this injectable med is real. But here’s the million-dollar question: Does semaglutide actually increase metabolism?
Short answer: not directly. While semaglutide is very effective at helping people lose weight, it doesn't supercharge your metabolism like a magic switch. Instead, it works by changing how your body and brain respond to hunger, blood sugar, and food cues.
Curious to know more? Let’s bust some myths and get into how semaglutide really helps with weight loss and what you can do to support your metabolism along the way.
There’s a lot of misinformation floating around the internet, so let’s clear things up.
False. Semaglutide doesn’t crank up your metabolic rate. Instead, it helps you eat less, creating a calorie deficit, which leads to weight loss. Your metabolism may actually slow down a little as you lose weight (completely normal!).
Nope. You’ll still need to make some lifestyle changes. Semaglutide can help reduce appetite and cravings, but it won’t zap fat cells in your sleep.
While semaglutide has shown impressive results in clinical trials, it’s not a one-size-fits-all solution. Your response to the medication can vary depending on factors like age, gender, hormone levels, metabolic health, medical conditions, and lifestyle habits.
According to research, semaglutide is especially effective for:
Adults with a BMI of 30 or higher
Adults with a BMI of 27 or higher who also have weight-related health issues like type 2 diabetes, high blood pressure, or sleep apnoea
People with insulin resistance or pre-diabetes, who often struggle with appetite regulation and blood sugar control
However, it may be less effective or more risky for:
People with a history of thyroid cancer or pancreatitis
Those with certain gastrointestinal issues, as semaglutide slows digestion
Individuals who don’t follow a supportive eating and activity plan. The injection can help reduce cravings, but it won’t fix emotional eating or ultra-processed food habits on its own
If only! While semaglutide helps with appetite control, healthy eating and regular movement still matter big time. In fact, clinical trials show that people using semaglutide alongside lifestyle changes, like a reduced?calorie diet, increased physical activity, and behavioural counselling, can lose up to 16% of their body weight over ~68 weeks, compared to only ~5.7% in those using lifestyle changes plus placebo.
Think of it as a helpful tool, not a total shortcut. You still have to put in some of the work.
Weight loss is only permanent if the habits stick. Some people regain weight after stopping the injections, especially if they haven’t built lasting routines.
That’s because semaglutide doesn’t rewire your lifestyle. It helps while you’re using it, but maintenance is up to you. To keep the weight off, long-term nutrition, movement and mindset still play a huge role.
Definitely not. In fact, losing weight too quickly without strength training can lead to muscle loss, which is bad news for your metabolism.
Muscle is your body’s metabolic engine. Less muscle means slower calorie burn, even at rest. So if you're on semaglutide, grab those dumbbells and make resistance training your best friend.
Actually, it does the opposite. Semaglutide slows down stomach emptying, which helps you feel fuller for longer, but it’s not a digestive booster.
This is great for controlling appetite and avoiding overeating, but not ideal for people with gastroparesis or certain gut issues. If your digestion already runs slow, speak with your doctor before starting semaglutide.
So, if it’s not a metabolism booster, how does it work? Here's what’s really going on behind the scenes:
Semaglutide is like your brain’s built-in ‘I’m full’ switch, just way more reliable. It mimics the GLP?1 hormone, which tells your body you’ve had enough food, even if your eyes are still on dessert.
Reduces food cravings
That 9pm snack attack? Way easier to ignore. Semaglutide helps dial down those intense cravings for sugary or greasy foods, so you’re not constantly thinking about your next treat. One study even found people had better control over their eating—less ‘I need chips now’ and more ‘meh, I’m good’.
Sounds gross, but it’s actually genius. Semaglutide slows down how quickly your stomach empties. That means you stay full longer after eating, which helps prevent those ‘still hungry’ moments 30 minutes after a meal. It’s like stretching out your satiety timeline without extra food.
You know that energy crash that hits after a sugary lunch? Semaglutide helps smooth that out by keeping your blood sugar more stable. It boosts insulin, reins in excess sugar, and helps you avoid the hangry rollercoaster.
Supports smaller meal portions
Instead of needing a mountain of food to feel satisfied, semaglutide helps you feel good with a normal-sized plate. You’re not forcing yourself to eat less. Your body just doesn’t demand more. It’s portion control without the punishment.
Something wild happens when you're on semaglutide. You start wanting healthier foods. It’s not mind control, but it does tweak brain signals linked to cravings and reward. That chocolate bar might not hit the same spot when your brain’s rooting for a salad.
Here’s the magic: semaglutide helps you eat less, which creates a calorie deficit without you counting every crumb. In one study, users ate 35% fewer calories at lunch and no, they weren’t starving. That kind of reduction leads to real, consistent weight loss over time.
Want to keep your metabolism happy while on semaglutide? These habits make a big difference:
Doing strength training – Lifting weights or doing resistance exercises 2–3 times a week helps preserve muscle mass, which keeps your metabolism strong.
Walk daily – Even light movement counts. Aim for at least 7,000–10,000 steps a day to keep your body active.
Eat enough protein – Protein is essential for muscle repair and also boosts your metabolism slightly during digestion.
Drink more water – Staying hydrated helps with digestion and can even give your metabolism a mini boost.
Get enough sleep – Poor sleep messes with hunger hormones and can slow down your metabolism.
Avoid skipping meals – Skipping meals can lead to blood sugar crashes and overeating later.
Limit stress – Chronic stress = elevated cortisol, which can mess with fat storage and slow your metabolism.
Don’t rely only on the injection – Semaglutide is a tool, not a shortcut. Pair it with healthy habits for the best results.
Semaglutide isn’t a metabolism booster, but it is a powerful tool for weight loss. By helping you eat less, reduce cravings and feel fuller longer, it supports your journey in a real and sustainable way. That said, your metabolism still needs a little love.
Building muscle, eating well, moving your body and managing stress are key to keeping your metabolism ticking along nicely, with or without semaglutide.
Want to dive deeper into how semaglutide works in the body? Check out our article What Is Semaglutide And How Does It Work for Weight Loss? for a science-backed breakdown.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.