I dropped 8 stone & 8 dress sizes in 6 months on Mounjaro – I’ve got no loose skin but did have a disgusting 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.

This gas is produced when sulfur-containing foods break down in the digestive system or when certain bacteria in the gut produce it during digestion.

Sulfur burps are also a common side effect of Mounjaro due to its effects on digestion and the gut microbiome. Here’s why:

Slower Digestion

Mounjaro slows gastric emptying, meaning food stays in your stomach longer. This can cause fermentation, leading to the production of hydrogen sulfide gas, which smells like rotten eggs.

Changes in Gut Bacteria

Mounjaro may alter the gut microbiome, leading to an overgrowth of certain bacteria that produce sulfur-containing gases. This is especially common if there’s an imbalance in gut flora.

High-Protein or High-Sulfur Diet

Since Mounjaro users often focus on high-protein diets for weight loss, foods like eggs, dairy, meat, and cruciferous vegetables (broccoli, cauliflower) can contribute to sulfur burps.

Gastrointestinal Side Effects

Mounjaro is known to cause bloating, nausea, diarrhoea, and constipation—all of which can contribute to sulfur burps by slowing digestion or altering gut bacteria.

How to reduce sulfur burps whilst using Mounjaro:

• Eat smaller meals to help with digestion.

• Stay hydrated to keep digestion moving.

• Avoid high-sulfur foods (eggs, garlic, onions, carbonated drinks).

• Probiotics may help balance gut bacteria

• Ginger or peppermint tea can ease digestion.

• Talk to your doctor if burps are severe or persistent.

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.