GLP-1 Plateaus: Why Weight Loss Can Slow Down

Around 2 in 3 Australian adults — about 13 million people — were living with overweight or obesity in 2022–24, and the Australian Institute of Health and Welfare now describes overweight and obesity as a leading risk factor contributing to ill health and death in Australia.

That statistic is big. But if you’re one of the many Australians using, considering, or simply reading about GLP-1 weight loss medication in Australia, the more personal question might be smaller and more frustrating:

“Why did I lose weight at first… and now nothing is happening?”

If you’ve hit a GLP-1 plateau, you’re not alone. A weight loss plateau can feel like the medication has stopped working, your body is “fighting back”, or you’ve done something wrong. But in many cases, slowing weight loss is not a sign of failure. It can be a predictable part of how weight loss works — especially once your body has adjusted to a lower weight, lower appetite, different eating patterns, and a new metabolic rhythm.

In this guide, we’ll unpack why GLP-1 weight loss can slow down, what’s considered normal, how to think about plateaus without panic, and when it’s worth reviewing your plan with a doctor. We’ll keep it practical, evidence-based, and relevant for Australians navigating weight management in the real world — busy workdays, family meals, supermarket choices, medication costs, and all.

This article is general education only and is not a substitute for personalised medical advice. GLP-1 medicines are prescription-only in Australia and should only be used under medical supervision.

First, what do GLP-1 medicines actually do?

GLP-1 medicines are often discussed online as if they “melt fat”. That’s not quite right.

GLP-1 receptor agonists are medicines that mimic or influence natural gut-hormone pathways involved in appetite, fullness, blood glucose regulation and gastric emptying. The Therapeutic Goods Administration notes that GLP-1 receptor agonists, such as semaglutide, liraglutide and tirzepatide, are prescription-only medicines used for type 2 diabetes and, in some cases, weight management under medical supervision.

In plain English, these medicines may help some people:

• feel full earlier in a meal
• feel less hungry between meals
• experience fewer cravings or less “food noise”
• reduce overall energy intake
• maintain weight loss more effectively when combined with ongoing lifestyle changes

In Australia, the Pharmaceutical Benefits Advisory Committee has noted that three injectable medicines are registered on the Australian Register of Therapeutic Goods for weight management: tirzepatide, liraglutide, and semaglutide.

If you’d like a broader explainer, we’ve covered the basics in our guide to GLP-1 weight loss medications explained simply. You can also read our guide on eligibility for weight loss medication in Australia if you’re wondering how doctors assess whether medication may be appropriate.

What is a GLP-1 plateau?

A GLP-1 plateau is a period where weight loss slows significantly or pauses after earlier progress while using a GLP-1 or related weight loss medication.

There isn’t one universal definition that applies to everyone. In everyday terms, people often describe a plateau as several weeks where the scale barely moves despite continuing their medication and trying to follow their plan.

A plateau might look like:

• losing 8 kg over the first few months, then staying within the same 1–2 kg range
• noticing your appetite is still lower, but weight loss has slowed
• losing centimetres from your waist while the scale stays similar
• having a few weeks of ups and downs that average out to “no change”
• feeling like the early “wow” effect of the medication has faded

Importantly, a plateau does not automatically mean the medication has stopped working. Weight loss is rarely a straight line. It is more like driving across Australia: sometimes you cover ground quickly, sometimes you hit roadworks, sometimes you detour, and sometimes you’re still moving even though the scenery looks the same.

What clinical trials show about slowing weight loss

The idea that weight loss slows over time is not just something people talk about in Facebook groups or Reddit threads. It shows up in clinical research too.

In the STEP 1 trial, adults with overweight or obesity who used once-weekly semaglutide 2.4 mg plus lifestyle intervention lost an average of 14.9% of baseline body weight by week 68, compared with 2.4% in the placebo group. That is substantial average weight loss — but it did not happen as a perfectly steady weekly drop forever. In the trial report, weight loss was observed from early in treatment and reached its lowest average point around week 60.

In another semaglutide trial, STEP 4, people who continued semaglutide after a run-in period maintained and continued weight loss, but the researchers noted that weight loss reached a plateau around weeks 60 to 68.

Tirzepatide trials show a similar “large early loss, then slowing” pattern. In SURMOUNT-1, adults without diabetes using once-weekly tirzepatide lost an average of 15.0%, 19.5%, and 20.9% at the 5 mg, 10 mg, and 15 mg doses respectively by week 72, compared with 3.1% with placebo. Again, impressive averages — but not a promise of endless weekly weight loss.

This is a key point: plateauing is not unusual, even in successful treatment.

Why weight loss slows down on GLP-1 medication

Let’s break down the common reasons a weight loss plateau happens.

1. Your body is smaller, so it burns less energy

This is one of the least glamorous but most important explanations.

When your body weight decreases, your body generally needs less energy to move, breathe, circulate blood, digest food and carry you through the day. A 100 kg body and an 85 kg body do not have the same daily energy requirement.

That means the eating pattern that created weight loss early on may later become closer to maintenance. You may still be eating less than before medication, but not quite little enough to continue losing at the same rate.

This is not “starvation mode” in the dramatic internet sense. It is basic biology: a smaller body usually has lower energy needs. Weight-loss research has long recognised that energy expenditure falls during weight loss and that plateaus commonly emerge after months of treatment.

2. Early weight loss often includes water and glycogen shifts

Many people lose weight faster in the first few weeks. Some of that may be fat loss, but some can also be water weight, changes in carbohydrate storage, reduced sodium intake, less food volume in the gut, or changes in inflammation and bloating.

Later, when the body settles, fat loss becomes slower and less dramatic on the scale.

This is why the first month can feel exciting — and month four can feel unfair.

3. Appetite may improve slightly after the early “honeymoon”

Some people describe their first few weeks or months on GLP-1 treatment as a switch being flipped. They feel full quickly, cravings quieten, and snacking drops almost automatically.

Over time, that effect may feel less intense. This does not always mean the medicine is ineffective. It may mean your body and habits have adjusted. You may still be eating less than before, but perhaps portions have crept up slightly, grazing has returned, or high-kilojoule foods are easier to tolerate again.

The tricky part is that this can happen subtly. A few extra bites at dinner, milky coffees, weekend alcohol, takeaway sauces, or “healthy” snacks can add up without feeling like you’ve changed much.

4. Movement often drops without you noticing

When people eat less, feel nauseated, lose weight quickly, or feel fatigued, they may unconsciously move less.

This includes formal exercise, but also non-exercise activity: walking to the shops, taking stairs, standing while working, doing housework, fidgeting, gardening, and generally being on your feet. These small movements can make a meaningful difference over a week.

If your medication helped reduce appetite but also left you tired, queasy or under-fuelled, your daily activity may have quietly dropped — and that can contribute to a weight loss plateau.

Australian physical activity guidance for adults recommends being active most days, preferably every day, including moderate-to-vigorous activity, muscle-strengthening activities on at least 2 days per week, and limiting sedentary time.

5. Muscle loss can reduce metabolic rate

Any weight loss can include a mix of fat mass and lean mass. The goal is not simply to lose weight — it’s to improve health while preserving as much muscle, strength and function as possible.

If you are eating very little protein, skipping meals because you feel too full, or not doing resistance training, you may lose more lean mass than ideal. This can affect strength, energy, long-term metabolic health and weight maintenance.

This is one reason a “just eat as little as possible” approach can backfire. On GLP-1 medication, many people need to be intentional about nutrition because appetite can become so low that they miss key nutrients.

6. Side effects can disrupt consistency

Common GLP-1 side effects are often gastrointestinal — nausea, constipation, diarrhoea, reflux, bloating or vomiting. Healthdirect notes that gut-related side effects are common with weight loss medicines.

Side effects can affect weight loss in different ways. Some people eat very little for a few days, then overeat when they feel better. Others avoid protein and vegetables because they feel heavy, then rely on toast, crackers, sweets or takeaway. Some stop exercising because they feel unwell. Others become constipated, which can mask fat loss on the scale.

A plateau sometimes reflects not lack of effort, but a plan that has become hard to live with.

7. The dose, schedule or medication may need review

GLP-1 and related medicines are usually started at lower doses and increased gradually to improve tolerability. A person may plateau because they are still on an early dose, have delayed dose escalation due to side effects, missed doses, used the medicine inconsistently, or misunderstood injection technique.

That does not mean you should increase your dose yourself. Do not double up, shorten intervals, restart after a break without advice, or copy someone else’s dosing schedule online. A plateau is a reason to review your plan with a doctor — not to experiment alone.

8. Other medicines or health conditions may be playing a role

Weight can be influenced by many factors beyond food and exercise. These may include:

• thyroid disease
• polycystic ovary syndrome
• menopause and perimenopause
• insulin resistance or diabetes changes
• sleep apnoea
• depression, anxiety or chronic stress
• corticosteroids
• some antidepressants, antipsychotics or epilepsy medicines
• reduced mobility due to pain or injury
• alcohol intake
• shift work and poor sleep

If your weight loss has stopped suddenly, your symptoms have changed, or you feel unusually tired, cold, constipated, low in mood, dizzy or unwell, it’s worth checking in with a clinician.

What is “normal” weight loss on GLP-1 medication?

This is the question everyone wants answered — and the honest answer is: it varies.

Clinical trials provide averages, not guarantees. Some people lose more than the average. Some lose less. Some respond early. Some are slower responders. Some stop because side effects outweigh benefits. Others do well but still plateau before reaching the number they had in mind.

A few helpful expectations:

Weight loss is usually faster at first

Many people notice the biggest change in appetite and portions early in treatment, particularly after dose increases. Weight may drop more quickly at the start, then slow.

Slower loss is still progress

A shift from losing 1 kg per week to 0.2 kg per week can feel disappointing, but it may still be meaningful. Sustainable weight management often requires patience, especially once you’re months into treatment.

Maintenance is not failure

If you have lost 5%, 10%, 15% or more of your starting weight and are now maintaining, that may already be clinically important. Healthdirect notes that losing even 5–10% of body weight can have significant health benefits and reduce risk of complications.

Plateaus can be a sign your plan needs updating

A plateau is not a moral failure. It is data. It tells you that your current medication, nutrition, movement, sleep, stress and health factors are producing maintenance at your current weight. The next step is to review what can safely and realistically be adjusted.

The emotional side of a weight loss plateau

Let’s be honest: plateaus can mess with your head.

You might think:

• “I knew this wouldn’t work for me.”
• “Everyone else is losing faster.”
• “I’ve wasted money.”
• “My body is broken.”
• “I should eat almost nothing to force the scale down.”

These thoughts are understandable, but they can push you toward extremes. And extremes are rarely helpful.

Weight management is not just maths. It involves biology, behaviour, environment, mental health, medical history, cost, family routines, culture, food access and stigma. The AIHW has highlighted that many drivers of overweight and obesity sit outside individual control, including the environments people live in.

So if you’re stuck, try to swap self-blame for curiosity:

• What has changed since the first month?
• Am I eating enough protein and fibre?
• Has my movement dropped?
• Am I sleeping properly?
• Am I constipated or retaining fluid?
• Am I taking the medication exactly as prescribed?
• Is my goal still medically appropriate?
• Do I need a plan for maintenance rather than more loss?

Curiosity creates options. Shame usually just creates silence.

Practical strategies that may help during a GLP-1 plateau

Before changing medication, it’s often worth reviewing the basics. Not because “diet and exercise solve everything”, but because GLP-1 medications work best as part of a broader plan.

1. Track patterns for one week — without judgement

You don’t need to track forever. But a short, honest snapshot can be useful.

For 7 days, consider noting:

• meal timing
• protein sources
• fruit and vegetable intake
• alcohol
• sugary drinks, juices, coffees and smoothies
• takeaway or restaurant meals
• snacks
• hunger and fullness
• bowel habits
• steps or activity
• sleep
• medication timing and side effects

The aim is not perfection. It’s to find clues.

Many people discover one or two obvious plateau drivers: skipping protein at breakfast, grazing after dinner, reduced walking, constipation, weekend kilojoules, or fatigue from under-eating.

2. Prioritise protein at meals

Protein helps support muscle maintenance and fullness. On GLP-1 medication, it can be easy to eat tiny portions and accidentally miss protein.

Practical Australian meal ideas include:

• Greek yoghurt with berries
• eggs with wholegrain toast
• tuna or salmon salad
• chicken and vegetable soup
• tofu stir-fry
• lean mince with beans and vegetables
• cottage cheese on grainy crackers
• lentil curry
• grilled fish with salad
• protein-rich smoothies if solid food is difficult

If nausea is an issue, smaller portions spread across the day may be easier than large meals.

3. Build meals around fibre and nutrient density

The Australian Dietary Guidelines apply to Australians with common diet-related risk factors such as being overweight, while noting that people with specific medical conditions may need tailored advice.

A plateau-friendly plate usually includes:

• a protein source
• plenty of vegetables or salad
• a high-fibre carbohydrate if tolerated, such as oats, legumes, brown rice, wholegrain bread or potato
• a small amount of healthy fat
• water as the default drink

This does not need to be fancy. A supermarket roast chicken, salad kit and microwave brown rice can be a perfectly reasonable weeknight meal.

4. Add resistance training, not just cardio

Walking is excellent, but muscle-strengthening matters too. The Australian adult movement guidelines recommend muscle-strengthening activities on 2 or more days per week.

This could include:

• gym weights
• resistance bands
• bodyweight squats
• wall push-ups
• Pilates
• supervised strength classes
• carrying groceries
• sit-to-stand exercises

If you have joint pain, a heart condition, pregnancy, dizziness, injury, or haven’t exercised in a long time, check with a health professional before starting.

5. Increase everyday movement

You don’t have to become a marathon runner. Often, the most sustainable change is increasing daily movement.

Try:

• a 10-minute walk after lunch or dinner
• parking slightly further away
• getting off public transport one stop earlier
• standing during phone calls
• walking while listening to podcasts
• taking stairs when practical
• doing short “movement snacks” between meetings
• weekend walks with family or friends

The aim is to make movement normal, not heroic.

6. Manage constipation early

Constipation is common with appetite changes, lower food volume, reduced fluids and some medications. It can make the scale look stuck, worsen nausea, and make you feel sluggish.

Helpful basics include:

• drinking enough fluid
• including fibre gradually
• walking daily
• not ignoring the urge to go
• discussing safe laxative options with a pharmacist or doctor if needed

Seek medical advice promptly if constipation is severe, painful, associated with vomiting, or you cannot pass wind.

7. Review alcohol and liquid kilojoules

Alcohol can slow progress in several ways: it adds energy, can increase snacking, disrupts sleep, worsens reflux, and may make next-day movement less likely.

Similarly, liquid kilojoules can sneak in through:

• large milky coffees
• juices
• smoothies
• soft drink
• sports drinks
• bubble tea
• cocktails
• “healthy” café drinks

You don’t have to cut everything forever. But if you’re plateauing, liquids are worth reviewing because they often don’t produce the same fullness as solid food.

8. Sleep like it’s part of the prescription

Sleep affects hunger, cravings, decision-making, energy and activity. Australian adult movement guidance recommends 7–9 hours of good quality sleep with consistent bed and wake times.

If you snore heavily, wake gasping, feel exhausted despite enough hours in bed, or have morning headaches, ask a doctor about sleep apnoea. Treating sleep problems can support weight management and overall health.

9. Don’t chase rapid loss at the expense of health

Very low intake can increase the risk of fatigue, dizziness, nutrient gaps, gallstones, muscle loss, constipation and rebound eating. If you are regularly unable to eat enough, vomiting, or feeling weak, your plan needs review.

Weight loss medication should support health — not make daily life miserable.

When should you review a GLP-1 plateau with a doctor?

A plateau is worth discussing with a doctor if:

• your weight has not changed for several weeks despite consistent medication use
• you have troublesome side effects
• you are skipping meals because you feel too full or nauseated
• you have symptoms of dehydration
• you are losing weight too quickly
• you feel weak, dizzy or faint
• you have diabetes and your glucose readings are changing
• your mood has worsened
• you are planning pregnancy, pregnant or breastfeeding
• you use oral contraception and are taking tirzepatide
• you have upcoming surgery, endoscopy, colonoscopy or another procedure requiring anaesthesia or sedation
• you are considering changing dose, restarting after a break, or switching medication
• you are buying products online and are unsure whether they are legitimate

The TGA has updated advice for tirzepatide and oral contraceptives: patients using oral hormonal contraception are advised to switch to a non-oral method or add a barrier method for 4 weeks after starting tirzepatide and for 4 weeks after each dose escalation. The TGA also states that GLP-1 medicines are not recommended during pregnancy.

If you are having surgery or deep sedation, tell your surgeon, anaesthetist and prescribing doctor that you use a GLP-1 or dual GIP/GLP-1 medicine, as Australian guidance has highlighted risks related to delayed gastric emptying and aspiration during anaesthesia or deep sedation.

You should seek urgent medical care if you develop severe or persistent abdominal pain, repeated vomiting, signs of dehydration, chest pain, fainting, symptoms of pancreatitis, or thoughts of self-harm. The TGA has also aligned warnings across GLP-1 medicines regarding potential mood changes, including suicidal thoughts or behaviours, and advises monitoring for new or worsening depression or unusual changes in mood or behaviour.

Why you should avoid “GLP-1” products from unknown websites

When weight loss stalls, it can be tempting to look for cheaper, stronger or faster options online. Please be careful.

The TGA has warned Australians about imported unregistered GLP-1 products promoted online for weight loss, noting that products bought over the internet may be fake, contain incorrect or harmful ingredients, and may not meet the same standards of quality, safety and efficacy as TGA-approved medicines.

A legitimate prescription medicine should be prescribed by an appropriately qualified clinician and dispensed through a registered Australian pharmacy. If a website promises “no prescription”, “research peptides”, “oral GLP-1 drops”, celebrity endorsements, unrealistic results, or secret compounded versions, consider that a red flag.

Should you increase the dose if you plateau?

Maybe — but only after medical review.

Dose decisions depend on:

• your current medication and dose
• how long you’ve been on it
• side effects
• medical history
• other medicines
• pregnancy considerations
• blood glucose if you have diabetes
• weight-loss response so far
• BMI and waist changes
• blood pressure, cholesterol and other health markers
• whether the goal is further loss or maintenance
• cost and access

Sometimes the answer is dose adjustment. Sometimes it’s treating constipation or reflux. Sometimes it’s improving protein intake. Sometimes it’s strength training. Sometimes it’s accepting maintenance for a while. Sometimes it’s investigating another condition. Sometimes it’s stopping because risks or side effects outweigh benefits.

This is why personalised care matters.

What if you stop the medication?

This is another area where expectations matter.

Obesity is increasingly understood as a chronic, relapsing condition for many people, not a short-term willpower problem. Stopping medication may lead to increased appetite and weight regain for some people, especially if the underlying drivers of weight gain are still present.

In the STEP 1 extension study, participants who stopped semaglutide after 68 weeks regained a substantial proportion of the weight they had lost over the following year. In SURMOUNT-4, continued tirzepatide treatment maintained and added to initial weight reduction, while withdrawing tirzepatide led to substantial regain.

That does not mean everyone must stay on medication forever. It does mean stopping should be planned. A good maintenance plan may include nutrition support, physical activity, regular monitoring, relapse-prevention strategies, and medical review.

Where NextClinic fits in

At NextClinic, we understand that weight management is personal. A plateau can be frustrating, especially when you’ve invested time, money and hope into a treatment plan.

Through our Australian telehealth service, we can help eligible adults access doctor-led care online, including medical assessment, prescriptions where clinically appropriate, specialist referrals when needed, and follow-up advice. Our telehealth doctors review your history and symptoms rather than treating weight loss medication as a one-size-fits-all solution. You can learn more about our online weight loss consultations and prescription support.

If you’re already using medication and have hit a plateau, a review may help clarify:

• whether your current plan is still appropriate
• whether side effects are interfering with progress
• whether your dose schedule needs discussion
• whether another health condition should be checked
• whether your goal should shift toward maintenance
• whether a dietitian, psychologist, exercise physiologist or specialist referral may help

If a prescription is clinically appropriate, we can issue electronic prescriptions that can be used at Australian pharmacies. We’ve also written a simple guide to digital prescriptions if you’re new to eScripts.

A realistic way to think about your plateau this week

If you’re currently stuck, try this simple reset:

Choose one area to review for the next 7 days.

Not ten areas. Not your entire life. Just one.

You might choose:

• add protein to breakfast
• walk 10 minutes after dinner
• do two short strength sessions
• track fluids and constipation
• reduce alcohol for a week
• set a consistent bedtime
• book a medication review
• stop weighing daily and use a weekly average
• measure waist circumference instead of only scale weight
• prepare two easy high-protein meals for busy days

Small changes are less dramatic than a dose increase, but they are often the changes that make treatment sustainable.

The bottom line on GLP-1 plateaus

A GLP-1 plateau can feel discouraging, but it is often a normal part of weight management rather than a sign that you’ve failed.

Here are the most important takeaways:

• Weight loss commonly slows as your body becomes smaller and needs less energy.
• Clinical trials of GLP-1 and related medicines show major average weight loss, but also a pattern of slowing or plateauing over time.
• A plateau can be caused by metabolism, appetite changes, reduced movement, side effects, constipation, dose timing, sleep, stress, other medicines or medical conditions.
• Maintenance after meaningful weight loss can still be a health win.
• Do not change dose, restart, switch or combine medicines without medical advice.
• Avoid unregistered online “GLP-1” products, which may be unsafe or fake.
• If your plateau lasts several weeks, side effects are affecting your life, or you feel unwell, review your plan with a doctor.

This week, choose one plateau strategy and test it gently: add a protein-rich breakfast, take a post-dinner walk, book a doctor review, prioritise sleep, or check whether constipation is masking progress.

What strategy will you try first — and what did you notice after a week? Share your chosen step or your results in the comments.

References

• Growing rates of overweight and obesity in Australia - Australian Institute of Health and Welfare
• Imported unregistered GLP-1 weight-loss products | Therapeutic Goods Administration (TGA)
• Pharmaceutical Benefits Advisory Committee (PBAC) advice on equitable access to GLP-1 obesity treatments | Pharmaceutical Benefits Scheme (PBS)
• GLP-1 Weight Loss Medications Explained Simply
• Am I Eligible for Weight Loss Medication in Australia?
• Once-Weekly Semaglutide in Adults with Overweight or Obesity - PubMed
• Once-Weekly Semaglutide in Adults with Overweight or Obesity | New England Journal of Medicine
• Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial - PMC
• Tirzepatide Once Weekly for the Treatment of Obesity | New England Journal of Medicine
• Treatment Guidelines - Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults - NCBI Bookshelf
• Recommendations for adults (18 to 64 years) | Australian Government Department of Health, Disability and Ageing
• Weight loss medicine | healthdirect
• Obesity | healthdirect
• Australian Dietary Guidelines | NHMRC
• Updated contraception advice for Mounjaro (tirzepatide) | Therapeutic Goods Administration (TGA)
• GLP-1 receptor agonists - clinical practice recommendations | ANZCA
• GLP-1 RAs: warnings aligned over potential risk of suicidal thoughts or behaviours | Therapeutic Goods Administration (TGA)
• Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension - PMC
• Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial | Trials | JAMA | JAMA Network
• Online Weight Loss Consultations | Prescriptions sent via SMS
• A Simple Guide to Digital Prescriptions

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