Tirzepatide offers a new option for weight loss and blood sugar control – learn all about its effects, usage, and benefits.
The active ingredient tirzepatide, marketed under the name Mounjaro (manufacturer: Lilly), was approved for the treatment of type 2 diabetes in 2022, first in the USA and later in the EU. At the end of 2023, tirzepatide received approval for the treatment of obesity. The medication has also been available in Germany since May 2024.
In this article, we examine its mode of action, expected weight loss, suitability for specific patient groups, and potential side effects.
What is tirzepatide?
The active ingredient tirzepatide belongs to the group of incretin mimetics, which imitate the effects of certain hormones from the gut in the body. Incretins are natural digestive hormones released in the body after eating: they stimulate satiety and signal the body to release insulin. Tirzepatide acts as a dual agonist for GLP-1 and GIP, both of which belong to the incretin group and are crucial in regulating blood sugar and body weight.
How exactly does tirzepatide work?
While active ingredients like semaglutide or liraglutide only mimic one hormone, the active ingredient tirzepatide activates the hormones GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) occurring in the human body, with the goal of lowering blood sugar levels and increasing the feeling of fullness.
Some studies suggest that tirzepatide is therefore even more effective at impacting blood sugar and body weight than the active ingredients in other GLP-1 medications.
How exactly does tirzepatide work?
While active ingredients like semaglutide or liraglutide only mimic one hormone, the active ingredient tirzepatide activates the hormones GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) occurring in the human body, with the goal of lowering blood sugar levels and increasing the feeling of fullness.
Some studies suggest that tirzepatide is therefore even more effective at impacting blood sugar and body weight than the active ingredients in other GLP-1 medications.
Why is the effect better?
Synergistic effects through the hormonal action of tirzepatide
Improved insulin secretion
GLP-1 and GIP help increase insulin secretion from the beta cells of the pancreas. This insulinotropic effect is glucose-dependent, meaning it is enhanced at high blood sugar levels without increasing the risk of hypoglycemia (low blood sugar) at normal blood sugar levels. Tirzepatide therefore improves the insulin response, which no longer functions properly in type 2 diabetes.
Reduced glucagon secretion
Both hormones help decrease the release of glucagon (a hormone that increases blood sugar levels). This reduces glucose production in the liver and lowers blood sugar levels.
Delayed gastric emptying
GLP-1 slows down gastric emptying, which leads to a prolonged feeling of fullness and reduces food intake. This effect contributes to weight loss.
Appetite reduction and improved satiety
By imitating GLP-1, tirzepatide also influences centers in the brain responsible for the feeling of fullness. The result is reduced food intake and an increased sense of satiety.
Weight loss
The combination of reduced food intake, improved feelings of satiety, and the positive effects on glucose metabolism leads to significant weight loss in people who use tirzepatide.
Improvement in glycemic control
Tirzepatide not only improves insulin secretion and lowers glucagon levels, but also contributes to better control of blood sugar levels in people with type 2 diabetes. This reduces the risk of diabetes-related complications.
Lipid metabolism and cardiovascular effects
Although the primary focus of tirzepatide is on glucose metabolism and weight loss, there is evidence that the treatment can also have positive effects on lipid metabolism. This could potentially lead to an improvement in cardiovascular health, although further research is required to fully understand these effects.
Frequently asked questions about tirzepatide
Here you will find answers to key questions regarding usage, mechanisms of action, and potential side effects. This information is intended to help you use the medication safely and effectively and to provide you with the best possible information on all relevant topics concerning tirzepatide.
How much weight can you lose with tirzepatide?
The dual efficacy of tirzepatide was demonstrated in five global randomized, controlled phase 3 studies (SURPASS 1–5) with nearly 6,300 participants. In these scientific studies, the effect of tirzepatide was tested under various conditions and compared to other active ingredients. The studies each showed a stronger effect of tirzepatide in lowering long-term blood sugar (HbA1c). A greater weight loss was also observed with tirzepatide than with other active ingredients.
The exact amount of weight loss varies depending on the individual health condition and lifestyle, but some study participants reported a weight loss of up to 15% of their body weight over a period of 68 weeks. In the SURMOUNT study, some participants were even able to lose up to 20.9% of their body weight over a period of 72 weeks, depending on the dosage of the medication and their lifestyle.
Typically, one remains in each dosage phase for 4 weeks so that the body can gradually adjust to the medication and potential side effects, such as nausea or stomach discomfort, are reduced. If necessary, this phase can also be extended to ensure that the medication is well tolerated before the dose is increased further.
The study results after 72 weeks of use in detail:
- 5 mg tirzepatide – patients lost an average of 16% of their baseline weight
- 10 mg tirzepatide – patients lost an average of 21.4% of their baseline weight
- 15 mg tirzepatide – patients lost an average of 22.4% of their baseline weight
- Placebo (no active ingredient) – patients lost an average of 2.4% of their baseline weight
How should the weight-loss injection tirzepatide be stored?
Tirzepatide should be stored in the refrigerator at a temperature between 2°C and 8°C to ensure the effectiveness of the medication. Ensure that it does not freeze. If necessary, the medication can also be stored unrefrigerated at room temperature (up to 30°C) for up to 21 days. It is important to protect the pre-filled pens from light and keep them in their original packaging until use. It must not be used after the expiration date.
Who is the weight-loss injection tirzepatide suitable for?
Tirzepatide is suitable for adults with type 2 diabetes and for people with obesity (BMI ≥30 kg/m²) or overweight (BMI ≥27 kg/m²) in combination with at least one weight-related comorbidity (e.g., hypertension, dyslipidemia, obstructive sleep apnea, cardiovascular disease, prediabetes, or type 2 diabetes mellitus).
A prerequisite for the treatment of severe overweight or obesity is the willingness to undergo lifestyle intervention (dietary, exercise, and behavioral interventions), which includes reducing caloric intake and getting at least 150 minutes of exercise per week. If sufficient weight loss is not achieved with this basic therapy, tirzepatide can be used for weight loss.
What side effects are to be expected when taking tirzepatide?
To date, patients in studies have received tirzepatide for up to 2 years (104 weeks), and the side effects for the medication were investigated in a clinical development program. It includes 9 completed phase 3 studies involving 7,702 patients who took tirzepatide alone or in combination with other blood-sugar-lowering medications. Overall, the most frequently reported side effects during treatment were gastrointestinal disorders, i.e., affecting the gastrointestinal tract. The side effect profile is comparable to other GLP-1 receptor agonists; these reactions were mostly mild or moderate, occurred more frequently during dose increases, and decreased over time in patients.
Very common to common side effects:
- Nausea, diarrhea, constipation, bloating, belching, flatulence
- Hypoglycemia (low blood sugar)
- Hypersensitivity reactions, injection site reactions
- Fatigue
- Increased heart rate, lipase and amylase levels
Please refer to the medication's package insert for a complete list of possible side effects and read more in our blog post about tirzepatide side effects.
Contraindication: When should you not take tirzepatide?
Medications containing the active ingredient tirzepatide are not suitable for patients who are allergic to the active ingredient or any other component of the medication (e.g., glycerin, benzyl alcohol, phenol). Furthermore, caution is advised for individuals with a history of medullary thyroid carcinoma or for individuals with a family history of MEN-2 syndrome (Multiple Endocrine Neoplasia type 2).
What interactions can occur during treatment with tirzepatide?
Tirzepatide causes delayed gastric emptying and thus has potential effects on the absorption rate of simultaneously administered oral medications. This means that if you take other medications in addition to tirzepatide, the effect is generally maintained, but it may be delayed. Patients taking warfarin or digoxin, in particular, should consider the risk of a delayed effect, especially when starting therapy or increasing the dose.
What is the difference between tirzepatide and semaglutide medications?
Tirzepatide and semaglutide (sold under the brand names Wegovy for weight loss and Ozempic for the treatment of type 2 diabetes) are both injectable medications used for the treatment of obesity and type 2 diabetes. Despite their similarities in use, they have important differences in their mode of action and composition. Read all about the differences in our blog post: Mounjaro or Wegovy - what are the differences?
What alternative medications and active ingredients are there to tirzepatide?
Tirzepatide is currently the first and only active ingredient that acts as both a GLP-1 and GIP receptor agonist. Suitable alternatives, however, are other GLP-1 receptor agonists like semaglutide and liraglutide. For the treatment of type 2 diabetes, the medication Ozempic and other antidiabetic drugs like metformin are alternatives.
Based on your individual health conditions and treatment goals, a doctor can check your suitability for the medications at SoLean. If there are no medical concerns, you will receive the prescription including medication delivery.
What does tirzepatide cost? An overview of treatment costs
Weight-loss injections containing the active ingredient tirzepatide are considered one of the most effective medical options for weight loss. Yet many who are interested in the treatment wonder: What costs can I expect?
Costs dependent on the tirzepatide dosage
The costs vary depending on the dosage, as the pens are available in several strengths. At the beginning of therapy, there is usually a slow dose increase over several weeks. This means: monthly costs increase with the strength you ultimately reach and maintain.
Typically, the dose is increased every four weeks until an individual maintenance dose is found – this is often in the range of 10 to 15 mg. The higher the dose, the more expensive the treatment.
A pack usually contains four pre-filled pens, which corresponds to a monthly supply.
Example calculation: Costs for 6 months of tirzepatide treatment
Assuming an average dosage that increases over the first few months, one can expect an amount of about €2,400 for six months of treatment – around €400 per month. Depending on the pharmacy and dosage level, this amount may be slightly higher or lower.
Note: This sum serves as a guide and does not replace an individual price inquiry at the pharmacy.
If you are considering Mounjaro, you should ask yourself the following questions beforehand:
- Am I ready to invest in my health long-term?
- Are there medical reasons that support therapy with tirzepatide?
- Have I checked all options for cost coverage?
Is the tirzepatide injection covered by health insurance?
For the treatment of obesity (without comorbidities like type 2 diabetes), the weight-loss injection containing tirzepatide is currently not covered by statutory health insurance. In this case, you need a private prescription, and you must cover the costs yourself.
For type 2 diabetes, cost coverage may be possible in individual cases – for example, if tirzepatide is prescribed within the scope of the approved indication and other therapies have been exhausted. Private health insurance companies or certain supplementary insurances may also cover part of the costs, depending on the respective tariff.
- You can find more information here in our article: The weight-loss injection as a health insurance benefit. What do health insurance companies cover?
Where can I buy tirzepatide without a prescription?
Important: Tirzepatide is a prescription-only medication – purchasing it without a prescription is not legal in Germany and the EU, nor is it safe.
Why you should not buy tirzepatide without a prescription:
- Legal situation
Tirzepatide belongs to the group of prescription-only medications. Selling or purchasing it without a doctor's prescription violates the Medicines Act. Importation from abroad (e.g., from online shops or third countries like India or Turkey) is prohibited and can lead to criminal consequences.
- Health risks
Purchasing via unofficial or illegal sources (e.g., online shops without a prescription requirement) harbors significant risks:
- Counterfeit or contaminated products
- Incorrect dosages or expired goods
- No medical supervision regarding side effects, interactions, or contraindications
Especially with an active ingredient like tirzepatide, which intervenes deeply in the metabolism, medical accompaniment is indispensable.
Conclusion on weight-loss injections with tirzepatide as the active ingredient
Studies show that tirzepatide has an above-average effect on body weight and can therefore also offer long-term health benefits.
Before you get started, it is worth:
- seeking medical advice,
- checking a potential application for coverage of costs,
- and keeping long-term financial planning in mind.
Taking weight-loss medication should also always be combined with other measures, such as calorie reduction and regular exercise. You should also definitely seek medical help if you are unsure about anything or need a dosage adjustment.
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