I dropped 4 stone on fat jabs – people say it’s the ‘best glow-up’ they’ve seen but I had a very unexpected side effect

Wegovy – a modified version of type 2 diabetes drug Ozempic – and Mounjaro are the leading weight loss injections used in the UK.

Wegovy, real name semaglutide, has been used on the NHS for years while Mounjaro (tirzepatide) is a newer and more powerful addition to the market.

Mounjaro accounts for most private prescriptions for weight loss and is set to join Wegovy as an NHS staple this year.

How do they work?

The jabs work by suppressing your appetite, making you eat less so your body burns fat for energy instead and you lose weight.

They do this my mimicking a hormone called GLP-1, which signals to the brain when the stomach is full, so the drugs are officially called GLP-1 receptor agonists.

They slow down digestion and increase insulin production, lowering blood sugar, which is why they were first developed to treat type 2 diabetes in which patients' sugar levels are too high.

Can I get them?

NHS prescriptions of weight loss drugs, mainly Wegovy and an older version called Saxenda (chemical name liraglutide), are controlled through specialist weight loss clinics.

Typically a patient will have to have a body mass index (BMI) of 30 or higher, classifying them as medically obese, and also have a weight-related health condition such as high blood pressure.

GPs generally do not prescribe the drugs for weight loss.

Private prescribers offer the jabs, most commonly Mounjaro, to anyone who is obese (BMI of 30+) or overweight (BMI 25-30) with a weight-related health risk.

Private pharmacies have been rapped for handing them out too easily and video calls or face-to-face appointments are now mandatory to check a patient is being truthful about their size and health.

Are there any risks?

Yes – side effects are common but most are relatively mild.

Around half of people taking the drug experience gut issues, including sickness, bloating, acid reflux, constipation and diarrhoea.

Dr Sarah Jarvis, GP and clinical consultant at patient.info, said: “One of the more uncommon side effects is severe acute pancreatitis, which is extremely painful and happens to one in 500 people.”;

Other uncommon side effects include altered taste, kidney problems, allergic reactions, gallbladder problems and hypoglycemia.

Evidence has so far been inconclusive about whether the injections are damaging to patients' mental health.

Figures obtained by Flying Eze show that, up to January 2025, 85 patient deaths in the UK were suspected to be linked to the medicines.

Evaluate Your Caloric Intake

Mounjaro reduces appetite, which can make it easy to eat too little. If you're losing weight too fast (more than two to three lbs per week after the initial adjustment period), try:

• Tracking your food intake to ensure you're eating enough calories (apps like MyFitnessPal can help).
• Increasing protein intake to preserve muscle mass (aim for 0.6–1g per pound of body weight).
• Adding healthy fats and complex carbs (e.g., avocados, nuts, whole grains) for balanced energy.

Adjust Your Dosage (With Doctor’s Approval)

If your weight loss is too rapid or causing side effects, your doctor may:

• Pause dose increases or lower your dosage.
• Adjust your treatment plan to stabilise your weight loss.

Strength Training & Exercise

To prevent muscle loss:

• Incorporate resistance training at least two to three times per week.
• Stay active with low-impact exercises like walking or yoga.

Hydrate & Manage Electrolytes

• Drink enough water (Mounjaro can reduce thirst).
• Electrolytes matter – Consider adding magnesium, sodium, and potassium if you feel weak or fatigued.

Monitor for Malnutrition & Deficiencies

Rapid weight loss can cause vitamin/mineral deficiencies (especially B12, iron, and electrolytes). If you experience:

• Fatigue, hair loss, or dizziness, ask your doctor about supplements.

Consider Further Medical Guidance

If your weight loss is excessive or causing health concerns, speak with your healthcare provider.

They might adjust your dosage, diet, or exercise plan to help stabilise your weight loss.

Common side effects of injections such as Ozempic include:

Nausea: This is the most commonly reported side effect, especially when first starting the medication. It often decreases over time as your body adjusts.

Vomiting: Can occur, often in conjunction with nausea.

Diarrhea: Some people experience gastrointestinal upset.

Constipation: Some individuals may also experience constipation.

Stomach pain or discomfort: Some people may experience abdominal pain or discomfort.

Reduced appetite: This is often a desired effect for people using Ozempic for weight loss.

Indigestion: Can cause a feeling of bloating or discomfort after eating.

Serious side effects can also include:

Pancreatitis: In rare cases, Ozempic may increase the risk of inflammation of the pancreas, known as pancreatitis, which can cause severe stomach pain, nausea, and vomiting.

Kidney problems: There have been reports of kidney issues, including kidney failure, though this is uncommon.

Thyroid tumors: There’s a potential increased risk of thyroid cancer, although this risk is based on animal studies. It is not confirmed in humans, but people with a history of thyroid cancer should avoid Ozempic.

Vision problems: Rapid changes in blood sugar levels may affect vision, and some people have reported blurry vision when taking Ozempic.

Hypoglycemia (low blood sugar): Especially if used with other medications like sulfonylureas or insulin.