Reaching your target weight thanks to medication – for many overweight people, this sounds like a dream come true.
For this reason, modern GLP-1 weight loss medications, also known as weight loss injections or weight loss drugs, have been labeled a “revolution” or “game changer.”
For the first time, a medication with an attractive risk-benefit profile is available on the market, meaning the effectiveness of the treatment is well-balanced against potential health risks.
Figures from the WHO (World Health Organization) show that being overweight is more than just a “lifestyle problem” driven by exaggerated beauty ideals: as early as 2019, estimates suggested that one in eight people—more than 1 billion people worldwide—were obese, and that obesity was directly or indirectly responsible for approximately 5 million deaths.
Those who suffer from severe obesity are likely asking themselves: Which weight loss medication is right for me? We explain which approved medications and active ingredients are available, as well as their similarities and differences.
A direct comparison: Semaglutide vs. Tirzepatide vs. Liraglutide
First of all: Weight loss injections are not miracle cures. However, they are effective medical tools for supporting significant weight loss and maintaining a healthy weight in the long term.
For people with obesity, the question of which weight loss medication is best often arises. Obesity is a chronic disease defined by a Body Mass Index (BMI) of 30 or higher (BMI ≥ 30). It can also be treated with weight loss medications at a BMI of 27 or higher in conjunction with comorbidities such as type 2 diabetes or high blood pressure.
Various medications or weight loss injections are approved for the treatment of severe obesity, including the following: Wegovy, Saxenda, Mounjaro, and Ozempic—though the latter is used primarily for the treatment of type 2 diabetes. These medications contain the following active ingredients: Semaglutide (Ozempic and Wegovy), Tirzepatide (Mounjaro), and Liraglutide (Saxenda).
These active ingredients are approved by the European Medicines Agency (EMA) and are used in the treatment of type 2 diabetes and for weight loss. They all belong to the class of GLP-1 receptor agonists, or incretin mimetics, which mimic naturally occurring digestive hormones in the body. Essentially, they increase insulin secretion after meals, decrease glucagon secretion, slow down stomach emptying, and increase the feeling of fullness. This leads to insulin regulation, reduced food intake, and weight loss.
A weight loss medication is more than just a lifestyle drug!
Despite belonging to the same class, the active ingredients Semaglutide, Tirzepatide, and Liraglutide differ in their mode of action, effectiveness, and specific areas of application. Here is a direct comparison of these three medications:
Effect of Semaglutide: Ozempic and Wegovy
Brand names: Ozempic (for diabetes), Wegovy (for overweight and obesity)
Wegovy for the treatment of overweight was approved in the EU in 2022 and offers an effective solution for people who are significantly overweight.
Mode of action: Mimics the GLP-1 hormone, leading to increased insulin secretion, reduced glucagon secretion, slowed stomach emptying, and decreased appetite.
Application: Used both for the treatment of type 2 diabetes (Ozempic) and for weight reduction in those who are overweight or obese (Wegovy).
Effectiveness: Shows significant weight loss and improved blood sugar control, with Wegovy specifically developed for substantial weight loss in individuals with obesity.
Everything about the active ingredient Semaglutide: mechanism of action, side effects, and costs
Weight loss through Tirzepatide
Brand name: Mounjaro
Mounjaro was approved for weight loss in Germany in January 2024.
Mode of action: Unique, as it mimics both GLP-1 and GIP, which can lead to improved efficacy in lowering blood sugar levels and weight loss.
Application: Approved for the treatment of type 2 diabetes, but also shows significant results in weight loss in clinical studies.
Effectiveness: Clinical studies suggest that Tirzepatide may be more effective for weight loss than Semaglutide, especially at higher doses.
Everything about the active ingredient Tirzepatide: mechanism of action, side effects, and costs
GLP-1 medication: Liraglutide
Brand names: Victoza (for diabetes), Saxenda (for overweight and obesity)
Mode of action: Mimics the GLP-1 hormone, leading to similar effects as Semaglutide, though with a shorter duration of action, necessitating daily injections.
Application: Victoza is used to treat type 2 diabetes, while Saxenda is specifically approved for weight loss.
Effectiveness: Liraglutide has proven effective both in lowering blood sugar levels and supporting weight loss, with Saxenda being developed for significant weight loss in patients who are overweight or obese.
Everything about the active ingredient Liraglutide: mechanism of action, side effects, and costs
Are GLP-1 weight loss medications in tablet form coming in 2024?
GLP-1 receptor agonists like Semaglutide and Liraglutide are traditionally known as injections. This is because the GLP-1 receptor molecule is relatively large and fragile, and would be broken down quickly in the gastrointestinal tract if taken orally.
However, there is progress in the development of oral GLP-1 receptor agonists. The development of offering these medications in tablet form rather than injections is complex and requires special technologies to ensure the stability and bioavailability of the active ingredient.
Research in the field of oral GLP-1 receptor agonists is advancing, however, offering hope to patients who would benefit from the convenience of a tablet form.
Other weight loss medications
In addition to the well-known weight loss injections, there are other pharmacological options for treating obesity. These include various classes of active ingredients and dosage forms.
- Orlistat (Xenical, Alli): Orlistat is a lipase inhibitor that blocks the absorption of fat from food in the intestine. This reduces calorie intake, leading to weight loss. It is available in a prescription form (Xenical) and as a low-dose, over-the-counter version (Alli).
- Phentermine/Topiramate (Qsymia): This combination of an appetite suppressant (phentermine) and an anticonvulsant (topiramate) helps to suppress hunger and reduce calorie intake. It is generally used in severely overweight people with a Body Mass Index (BMI) ≥ 30 or ≥ 27 with comorbidities such as high blood pressure or type 2 diabetes.
- Naltrexone/Bupropion (Contrave): This combination of an opioid antagonist (naltrexone) and an antidepressant (bupropion) acts on the central nervous system to decrease feelings of hunger and increase feelings of satiety. It is also prescribed for people with a BMI ≥ 30 or ≥ 27 with comorbidities.
Evaluation of these weight loss medications compared to modern weight loss injections
Weight loss tablets
- Orlistat:
Mechanism of action: Blocks fat absorption in the intestine.
Advantages: Effective at reducing fat absorption and body weight.
Disadvantages: Common side effects are gastrointestinal, such as fatty stools and increased bowel movements.
Efficacy: Studies show that Orlistat leads to moderate weight loss, often less than with GLP-1 receptor agonists.
- Phentermine/Topiramate:
Mechanism of action: Appetite suppressant combined with an anticonvulsant.
Advantages: Effective weight loss and appetite control.
Disadvantages: Can lead to increased heart rate, insomnia, and other side effects.
Efficacy: Offers significant weight loss, but with potentially serious side effects.
- Naltrexone/Bupropion:
Mechanism of action: Acts on the central nervous system to control feelings of hunger.
Advantages: Can reduce food cravings and binge eating.
Disadvantages: Potential side effects include nausea, constipation, and headaches.
Efficacy: Moderate weight loss, but with risks of side effects.
Weight loss injections (GLP-1 receptor agonists)
- Semaglutide:
Mechanism of action: GLP-1 receptor agonist that reduces feelings of hunger and promotes insulin secretion.
Advantages: Leads to significant weight loss and improves blood sugar control.
Disadvantages: Possible side effects include nausea and gastrointestinal discomfort, especially at the start of treatment.
Efficacy: Outperforms many previous medications in weight loss and has additional benefits in diabetes treatment.
- Liraglutide:
Mechanism of action: GLP-1 receptor agonist that enhances feelings of satiety.
Advantages: Effective for weight reduction and blood sugar control.
Disadvantages: Side effects can include nausea and vomiting.
Efficacy: High efficacy in weight loss compared to traditional medications.
- Tirzepatide:
Mechanism of action: Dual GLP-1/GIP receptor agonist that promotes insulin secretion and satiety.
Advantages: Can offer significant weight loss and better blood sugar control.
Disadvantages: Potential side effects are similar to other GLP-1 receptor agonists.
Efficacy: Shows promising results and often exceeds the efficacy of older medications.
Which active ingredient is right for me?
Obesity is a chronic disease that may require pharmacological treatment to regulate body weight and blood sugar levels. Semaglutide, Liraglutide, and Tirzepatide are effective medications that can help patients with obesity and type 2 diabetes. The choice of the right medication should be made by taking individual health conditions into account and in consultation with medical professionals. The decision to use one of these medications should be made on an individual basis, based on specific health needs, weight loss goals, potential side effects, and advice from a healthcare provider.
Important considerations
Improving quality of life: The use of weight loss medications aims to increase the quality of life for people with obesity. Treatment should always take place in consultation with a physician, ideally in a specialized facility such as a university hospital or a department of diabetology.
Health insurance and costs: Currently, weight loss medications such as Semaglutide and Liraglutide are excluded from reimbursement by statutory health insurance funds, as they are considered lifestyle medications. However, people with type 2 diabetes may receive partial reimbursement for diabetes treatment. It is important to consider the costs and potential supply shortages.
Individual needs: The choice of the right medication depends on individual health conditions, such as the presence of comorbidities, and specific weight loss goals. A thorough medical evaluation by professionals is essential.
Conclusion: Weight loss injections for overweight, obesity, and diabetes
Semaglutide offers flexibility for the treatment of type 2 diabetes and overweight with two different products and has proven to be very effective in weight loss.
Tirzepatide is characterized by its dual mode of action, which may make it the most effective of the three medications in terms of weight loss and blood sugar control improvement.
Liraglutide offers solid options for both diabetes treatment and weight reduction, but requires daily injections and may be less effective for weight loss than Tirzepatide or Semaglutide in its specific formulation for weight loss (Wegovy).
Sources:
- Semaglutide: Gelbe Liste Pharmindex
- Widespread disease obesity: reaching your dream weight with diabetes medication?: DGE
- Overweight and obesity in adults: Springer
- Obesity: WHO
