Pharmacological Treatment of Obesity with GLP-1 and GIP/GLP-1 Receptor Agonists - Medical Experts

The weight-loss injection is a medicine used for the pharmacological treatment of obesity. Patients inject it themselves into the subcutaneous fatty tissue. Various active ingredients with different mechanisms of action are available for this purpose.

The active ingredient semaglutide in Wegovy mimics the body’s own hormone GLP-1. This increases the feeling of fullness, whilst reducing hunger and appetite. Tirzepatide in Mounjaro acts on receptors for the gut hormones GIP and GLP-1. In people with type 2 diabetes, it also affects blood sugar levels.

A doctor’s prescription may be considered for the following groups:

• Adults with a body mass index (BMI) of 30 or above.
• Adults with a BMI of 27 or above, if they have a weight-related comorbidity such as high blood pressure.
• Young people aged 12 and over who are obese and weigh more than 60 kilograms can be prescribed Wegovy as an injection.
• People with obesity for whom a diet and exercise programme has not been sufficiently effective.

The medicine is not intended for losing just a few kilograms. In cases of excess weight, it complements long-term measures for weight loss and weight management when these alone are not sufficient.

Before prescribing the medicine, the doctor will measure your body weight and height. Your BMI will be calculated from these measurements to check whether the medicine is approved for you. Any underlying medical conditions and medicines you are already taking will also be discussed.

Before starting treatment, you should raise the following points:

• Pancreas: Please report any previous episodes of pancreatitis.
• Gastric emptying: Any severe impairment of gastric emptying must be discussed before treatment with tirzepatide.
• Pregnancy: Semaglutide should not be used during pregnancy.
• Diabetes medicines: When taken with insulin or sulphonylureas, tirzepatide may cause hypoglycaemia.

People with diabetes mellitus therefore require a thorough review of their current treatment. If necessary, the doctor will adjust the dosage of other medicines.

Weight-loss injections can help reduce weight, but do not guarantee a specific outcome. Studies on Wegovy and Mounjaro show greater weight loss than with a placebo, i.e. a preparation containing no active ingredient.

One specific study examined adults with obesity who did not have type 2 diabetes. After 72 weeks, the average weight loss with tirzepatide was around 20 per cent and with semaglutide around 14 per cent of the baseline weight. This result applies to the group studied and does not allow for a reliable prediction for individual people.

Long-term medication may be necessary. In a Wegovy study, participants regained weight after stopping treatment, whilst those who continued treatment continued to lose weight. The medicine can therefore also help to maintain weight.

Following a briefing, patients can administer the medicine themselves at home. No hospitalisation is required. With a Wegovy single-use pen, the injection takes around 5 to 10 seconds.

The use of Wegovy usually proceeds as follows:

1. The medicine is injected under the skin once a week.
2. Suitable injection sites include the abdomen, thigh or upper arm.
3. The dose is gradually increased over 16 weeks to minimise gastrointestinal side effects.
4. Treatment is continued as long as the benefits and tolerability warrant it.

In adults, treatment with tirzepatide begins at 2.5 milligrams once a week. After four weeks, the dose is increased to 5 milligrams per week. Further use is determined by the doctor’s prescription.

Ozempic also contains semaglutide, but has a different marketing authorisation. It is used to treat type 2 diabetes when it is not adequately controlled. Semaglutide is authorised for weight loss under the name Wegovy.

The most common side effects affect the gastrointestinal tract. In clinical trials with semaglutide, nausea occurred in 43.9 per cent of those treated, diarrhoea in 29.7 per cent and vomiting in 24.5 per cent within 68 weeks.

In the same trials, constipation was observed in 24.2 per cent of patients on semaglutide and in 11.1 per cent on placebo. Tirzepatide may also cause nausea, vomiting, abdominal pain and diarrhoea.

Confirmed acute pancreatitis was reported in 0.2 per cent of those treated with semaglutide and in less than 0.1 per cent of those on placebo in the specified semaglutide studies. Severe, persistent abdominal pain radiating to the back requires immediate medical attention when taking tirzepatide.

Hypoglycaemia may occur when tirzepatide is used in combination with insulin or a sulphonylurea. This risk is assessed by a doctor before treatment begins.

During treatment, regular checks are carried out to ensure that your personal weight loss or weight maintenance target is being met. How well you tolerate the medicine also influences the decision on whether to continue treatment.

If you experience nausea, vomiting or diarrhoea at the start of treatment with tirzepatide, you should drink plenty of fluids to prevent dehydration. Severe or persistent symptoms must be investigated by a doctor.

If a Wegovy injection has been missed for more than five days, the missed dose should be skipped. The medication should not be administered again until the next scheduled day of treatment.

You should prepare for discontinuation, as your weight may increase again. Dietary changes, physical activity and behavioural measures therefore remain integral parts of the treatment for obesity.

The alternatives differ in terms of how they are used, the burden they entail and the possible side effects. A diet and exercise programme forms the basis of weight loss; medication may be added to this. In cases of severe obesity, surgical procedures may also be considered under certain conditions.

For patients paying out of pocket, the treatment costs around 130 to just under 500 euros per month, depending on the preparation and dosage. Medical supervision and laboratory tests may be charged separately. Due to the potentially high costs, funding should be clarified before treatment begins.

Statutory health insurance does not, as a rule, cover weight-loss injections intended purely for weight loss. However, for certain forms of treatment for type 2 diabetes, the medication may be covered by health insurance.

For those with private health insurance, reimbursement depends on the specific policy. You should clarify before starting treatment whether your insurance will cover the costs and under what conditions.

Your GP is the first point of contact for personal advice. Experienced endocrinologists and specialists in diabetology may also be suitable for treatment with GLP-1 agonists.

The additional medical specialism in nutritional medicine is a verifiable qualification. It requires specialist accreditation, further training and an examination, but is not a prerequisite for every prescription.

The following questions are useful for the initial consultation:

• Do I meet the criteria for a weight-loss injection?
• Which active ingredient is suitable for my medical conditions and the medicines I am already taking?
• How are dosage, side effects and treatment success monitored?
• What are the costs involved, including medical check-ups and laboratory tests?

Prescription-only medicines should only be obtained from an authorised pharmacy with a valid prescription. Offers without a prescription are a warning sign. You can find specialists in weight-loss injection treatment at the end of this text.