Ozempic Side Effects: What You Need to Know

Key Takeaways

• High discontinuation rate: The majority of people stop taking Ozempic within a few months, primarily due to gastrointestinal issues.
• Common side effects: 44% experience nausea, 30% diarrhoea, 24% vomiting, and 24% constipation.
• Substantial muscle loss: Up to 40% of weight loss consists of lean muscle mass – almost double the proportion seen in standard weight loss.
• Ageing effect: The muscle mass loss is equivalent to more than 10 years of natural ageing.
• Ozempic face: Rapid weight loss leads to sagging skin, hollowed cheeks, and premature facial volume loss.
• Surgical risks: Ozempic should be stopped at least 3 weeks before surgery.
• Weight regain: After stopping the medication, body fat returns, but lean muscle mass may not.
• Resistance training helps: Strength training can reduce muscle loss by 50% or more.
• Dose-dependent: Increasing the dose gradually over several months minimises side effects.
• Low success rate: Only about 1 in 25 people achieve a normal body weight with Ozempic.

The Most Common Ozempic Side Effects

What are the most common Ozempic side effects for weight loss?

Based on clinical trials, 44 per cent of Ozempic users experience nausea, 30 per cent diarrhoea, 24 per cent vomiting, 24 per cent constipation, and 20 per cent abdominal pain. These gastrointestinal issues are the primary reason why most people discontinue treatment within a few months. Interestingly, 16 per cent of the placebo group also experienced nausea or diarrhoea, which means that not all symptoms can be directly attributed to the medication.

Side effects from semaglutide occur in virtually all clinical trials, yet only led to trial discontinuation in around 15 per cent of participants. The good news: most of these side effects improve significantly once the medication is stopped.

How long do Ozempic side effects last?

Most Ozempic side effects are dose-dependent and occur particularly often in the first four to eight weeks, during the dose-escalation phase. Studies show that these symptoms are classified as “mild to moderate” and typically improve once the body adjusts. However, the duration varies greatly between individuals – some people experience symptoms for only a few weeks, whilst others struggle with side effects for months.

What are the typical Ozempic side effects in the first week?

During the initial phase of Ozempic treatment, gastrointestinal symptoms are particularly pronounced. This is because GLP-1 receptor agonist medications significantly delay gastric emptying, which leads to increased feelings of satiety, but also nausea and vomiting. Experts therefore recommend starting with low doses and increasing them slowly – an approach known as “low and slow”.

Gastrointestinal Issues in Detail

How common are gastrointestinal problems?

The gastrointestinal side effects of Ozempic are exceptionally common and represent the greatest hurdle to treatment adherence. Significant digestive complaints have been documented in virtually all clinical trials. The reported frequency is as follows:

• Nausea: 44% (up to 40% according to published clinical data)
• Diarrhoea: 30% (up to 20% in other studies)
• Vomiting: 24%
• Constipation: 24% (up to 10% in other analyses)
• Abdominal pain: 20%

What to do about severe nausea caused by Ozempic?

If you experience severe nausea, several practical strategies can help:

• Dietary adjustments: Eat slowly and consume smaller portions. A low-fat diet reduces the strain on your stomach.
• Fluid intake: Take small sips of liquids. Stay well hydrated, but avoid sports drinks, dairy products, coffee, alcohol, and fizzy drinks.
• Natural remedies: Crackers, apples, peppermint, and ginger can help alleviate nausea. Getting plenty of fresh air is also beneficial.
• Adjusting dietary fibre: Depending on your symptoms, you may want to temporarily reduce or increase your fibre intake.
• Drinking around mealtimes: If symptoms are particularly severe, avoiding fluids during meals can help.
• Medical support: Your GP or pharmacist can prescribe anti-sickness medication to help ease side effects.

Important: Ozempic remains effective for weight reduction even without persistent nausea. The appetite-suppressing effect occurs independently of feeling sick.

Which dosage causes the fewest side effects?

The side effects of Ozempic are clearly dose-dependent. A gradual increase in dosage over several months – the “low and slow” method – significantly minimises gastrointestinal issues. Start with the lowest dose (0.25 mg) and only increase as quickly as your body tolerates. This measured approach can make all the difference between successful therapy and early discontinuation.

Muscle Loss Caused by Ozempic: An Underestimated Problem

Why does Ozempic cause muscle mass loss?

Ozempic leads not only to fat reduction, but also to an alarming degree of muscle mass loss. Whilst standard weight loss typically sees around 25 per cent of lost weight coming from lean mass (primarily muscle), with Ozempic this figure can reach up to 40 per cent – meaning almost half of the weight lost is muscle rather than fat.

People taking Ozempic or tirzepatide (Mounjaro) lose on average around 6 kilograms of muscle mass – equivalent to roughly an eighth of their total muscular mass. This degree of depletion is comparable to the muscle wasting seen in oesophageal or head and neck cancers. Although pharmaceutical manufacturers argue that the fat-to-muscle ratio still improves overall, this perspective overlooks a critical concern.

What can you do to prevent muscle loss?

The good news: muscle loss caused by Ozempic is not inevitable. Resistance training can reduce the proportion of lost lean body mass by half or more. Clinical studies clearly demonstrate the difference: whilst individuals on calorie restriction without exercise lose both fat and muscle, those undertaking resistance training largely preserve their lean muscle mass – losing 4 kilograms virtually without any muscle loss.

Supervised strength training adhering to the following guidelines yields the best results:

• 2–3 sessions per week
• A minimum duration of 10 weeks
• Targeting all major muscle groups
• Weight training is more effective than cardio alone
• Younger individuals and men tend to build more muscle mass

These exercise programmes should be started without delay as soon as someone begins Ozempic therapy. Otherwise, the muscle mass loss is equivalent to the natural decline experienced over a decade or more of ageing – a cost that is entirely avoidable with proper training.

The “Ozempic Face” Phenomenon

What is “Ozempic Face” and how does it happen?

“Ozempic Face” is a media term used to describe the altered facial appearance caused by rapid weight loss. It is characterised by sagging skin, hollowed cheeks, an overall aged and dull complexion, deeper nasolabial folds, and sunken eye contours. Whilst initially assumed to be purely a consequence of facial volume loss and fat reduction, the underlying picture is more complex.

Premature facial ageing and changes in skin health appear to be multifactorial: alongside fat loss, there are direct effects on stem cells as well as on the production and secretion of hormonal and metabolic factors. These changes compromise the structural integrity and barrier function of the skin and can also lead to a reduction in facial musculature, further exacerbating the aged appearance.

How does Ozempic affect the face?

Rapid weight loss – often losing up to 20 per cent of total body weight over 5 to 8 months – causes a rapid depletion of facial fat pads. At the same time, collagen and elastin fibres break down at an accelerated rate. The result is a face that appears markedly older than before starting treatment. Not everyone using weight-loss jabs develops “Ozempic Face”, but the risk increases with the speed and extent of weight loss.

How can you treat “Ozempic Face”?

As preventative measures, you can take the following steps:

• Gradual weight loss: 1–2 kg per month is optimal to give your skin time to adjust.
• Good hydration: Drinking plenty of water supports skin elasticity.
• Balanced nutrition: A nutrient-rich diet promotes healthy skin.
• Regular physical activity: Helps maintain facial muscle tone.
• Sun protection: Daily SPF prevents additional premature ageing.

Treatment options for existing Ozempic Face include:

• Retinol creams to stimulate collagen production
• Laser therapy for skin tightening
• Microneedling to encourage skin regeneration
• Hyaluronic acid dermal fillers to restore facial volume
• Consultation with a plastic surgeon in more pronounced cases

Ozempic and Surgery: Critical Risks

Why should you stop taking Ozempic before surgery?

GLP-1 receptor agonist medications slow gastric emptying so substantially that anaesthetic guidelines, including those from the American Society of Anesthesiologists, recommend stopping these medications up to a week prior to scheduled procedures. The reason: the risk of undergoing general anaesthesia with a full stomach and aspirating gastric contents into the lungs is significantly elevated. However, studies indicate that even one week may not be sufficient.

Patients taking GLP-1 medications had a higher prevalence of increased residual gastric contents despite fasting – even when they had stopped the medication a week beforehand. For elective (planned) surgical procedures, you should therefore consider stopping Ozempic at least three weeks in advance.

When should you stop taking Ozempic?

For people with diabetes who take Ozempic for blood sugar control, pausing the medication for a month may not be clinically advisable. However, if you are taking the medication solely for weight management, stopping well in advance of surgery is strongly recommended. Always discuss the timing with your GP, specialist, and anaesthetist, ideally at least a month before your planned operation.

Preventing and Managing Ozempic Side Effects

How Can You Prevent Ozempic Side Effects?

Preventing Ozempic side effects starts with the right dosing strategy. The “low and slow” approach – starting at a low dose and increasing gradually over many months – significantly reduces gastrointestinal issues. In addition, the following steps can help:

• Switching your diet to smaller, lower-fat meals
• Ensuring adequate, but not excessive, fluid intake
• Starting a resistance training programme immediately
• Attending regular medical reviews
• Maintaining realistic expectations for weight loss

What Are the Rare but Serious Side Effects?

Alongside common gastrointestinal issues, rarer but more serious adverse reactions may occur with Ozempic:

• Inflammation of the pancreas (pancreatitis): A potentially life-threatening condition
• Gallbladder issues: Gallstones can form due to the rapid breakdown of cholesterol from fat cells, similar to sugar crystallising in bile
• Kidney failure: Increased risk for patients with pre-existing renal conditions
• Thyroid cancer: A theoretical risk that continues to be investigated
• Allergic reactions: Ranging from mild skin rashes to severe systemic allergic reactions
• Hypoglycaemia: Particularly when used in combination with insulin or other diabetes medications

How Dangerous Are Ozempic Side Effects?

The majority of Ozempic side effects are mild to moderate and improve after discontinuing the medication. According to current clinical trials, serious adverse events occur only in rare instances. Nevertheless, the long-term implications should not be overlooked: substantial muscle mass loss carries potential consequences for overall health outcomes, including increased frailty and potentially higher long-term mortality risk – although these concerns remain theoretical at present due to a lack of long-term data.

Resistance Training as the Key to Success

What Role Does Resistance Training Play with Ozempic?

Resistance training is not optional, but essential for anyone taking Ozempic or similar GLP-1 receptor agonist medications. The scientific evidence is unambiguous: strength training can halve the proportion of muscle mass loss or even prevent it entirely. Numerous clinical studies show that combining calorie restriction with resistance training delivers markedly superior outcomes compared to diet alone.

Whilst the non-exercising group loses more total weight on an identical calorie deficit (because they lose more muscle tissue), the exercising group preserves their valuable lean muscle mass. In one study, the exercise cohort lost 4 kilograms seemingly without any muscle loss whatsoever – a remarkable difference.

Ozempic Side Effects for Weight Loss: What Are the Differences with Wegovy?

Both Ozempic and Wegovy contain the active substance semaglutide. The main difference lies in their licensing and available dosages: Ozempic is licensed primarily for type 2 diabetes, whereas Wegovy was developed specifically for chronic weight management and is prescribed in higher doses. Both share similar side effect profiles because they share the exact same mechanism of action. Tirzepatide (Mounjaro/Zepbound) is a newer dual incretin mimetic that targets two receptors and may be even more effective.

Ozempic Side Effects Long-Term and the Discontinuation Dilemma

What Happens to Weight After Stopping Ozempic?

Here lies one of the most significant challenges with Ozempic: most people stop taking the medication after just a few months – whether due to cost (around $1,000 per month in private treatment), side effects, supply shortages, or expiring prescriptions. And when you stop taking Ozempic, lost body fat tends to return. The major clinical concern is that lost muscle mass may not return along with it. The result? You may end up with a worse body composition than before starting treatment.

This weight cycling is associated with increased fat accumulation, especially around the midsection. MRI studies – the gold standard for visualising muscle mass – show that individuals who frequently cycle their weight up and down exhibit progressively poorer body composition. Each successive cycle compounds the problem.

What Natural Alternatives to Ozempic Are Available?

Rather than relying on expensive medications associated with potential side effects, there are natural ways to support endogenous GLP-1 levels:

• Plant-based nutrition: A whole-food, plant-based diet can naturally stimulate GLP-1 secretion
• High-fibre foods: Prebiotics, intact wholemeal grains, and leafy green vegetables promote GLP-1 production
• Thylakoid-rich foods: Leafy greens contain thylakoids, which help regulate appetite naturally
• Regular physical activity: Both resistance training and aerobic exercise enhance metabolic health
• Adequate sleep: Sleep deprivation disrupts hunger and satiety hormones
• Stress management: Chronic stress promotes weight gain and disrupts hormonal balance

These lifestyle strategies may work more gradually than a slimming injection, but they achieve sustainable results without the severe Ozempic side effects.

Scientific Sources

• Ryan DH, et al. (2024). Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial. Nature Medicine.
• Coutinho W, Halpern B. (2024). Pharmacotherapy for obesity: moving towards efficacy improvement. Diabetol Metab Syndr.
• Suran M. (2023). As Ozempic’s popularity soars, here’s what to know about semaglutide and weight loss. JAMA.
• Lupianez-Merly C, et al. (2024). Review article: Pharmacologic management of obesity – updates on approved medications, indications and risks. Aliment Pharmacol Ther.
• Singh A, Nissen SE. (2024). Contemporary management of obesity: a comparison of bariatric metabolic surgery and novel incretin mimetic drugs. Diabetes Technol Ther.
• NutritionFacts.org. How to Control the Side Effects (Including “Ozempic Face”) of GLP-1 Drugs.