08/07/2025
Introduction
Recently, there has been a significant increase in interest in new weight loss drugs within the context of general health and well-being for the adult population. Mounjaro and Wegovy represent a major breakthrough in addressing excessive body fat accumulation, but it is essential to fully understand their distinctive characteristics, practical efficacy, and limitations. In this article, we will analyze these drugs scientifically and impartially, providing clear information based on the latest evidence to allow everyone to make informed choices together with their physician.
The New Generation of Weight Loss Drugs
A New Scientifically Innovative Method
Mounjaro and Wegovy belong to a new class of drugs that act on incretin receptors, hormones produced by the gut that regulate glucose metabolism and the sense of satiety. Unlike previous weight loss drugs, these medications are not simple appetite suppressants, but complex modulators of energy metabolism.
The Italian Epidemiological Context
In Italy, according to the most recent ISTAT data, 10% of the adult population is obese and 35% is overweight. These numbers represent a significant health challenge, considering the comorbidities associated with excess weight: type 2 diabetes, cardiovascular diseases, metabolic syndrome, and certain forms of cancer.
Mounjaro: Characteristics and Mechanism of Action
The Tirzepatide Molecule
Mounjaro contains tirzepatide, a dual agonist of the GLP-1 (Glucagon-Like Peptide-1) and GIP (Glucose-dependent Insulinotropic Polypeptide) receptors. This dual action represents the main innovation compared to previous drugs:
- Action on GLP-1: reduces appetite, slows gastric emptying, and improves insulin secretion
- Action on GIP: further enhances glycemic control and contributes to body weight reduction
Clinical Efficacy of Mounjaro
Clinical studies published in peer-reviewed journals show:
- Average body weight reduction of up to 25% in 72 weeks
- Significant improvement in metabolic parameters (HbA1c, lipid profile)
- Reduction in waist circumference and visceral fat
Costs and Availability
The monthly cost of Mounjaro in Italy varies between €346 and €623, depending on the prescribed dosage. It is currently not reimbursed by the National Health Service for weight loss indications.
Wegovy: The Alternative with Semaglutide
Pharmacological Characteristics
Wegovy uses semaglutide, a selective GLP-1 receptor agonist. The molecule has been extensively studied and has demonstrated:
- Efficacy in reducing body weight (average of 16% in 68 weeks)
- Improvement in cardiovascular risk factors
- Well-characterized safety profile
Differences with Mounjaro
The main differences between the two drugs include:
- Mechanism: single receptor (GLP-1) vs. dual receptor (GLP-1/GIP)
- Efficacy: slightly lower weight loss compared to Mounjaro
- Cost: €220-300 per month, more economically accessible
- Clinical experience: greater for the semaglutide molecule
Indications and Contraindications
Eligibility Criteria
According to international guidelines, these weight loss drugs are indicated for:
- Adults with BMI ≥ 30 kg/m² (obesity)
- Adults with BMI ≥ 27 kg/m² with at least one weight-related comorbidity
- Patients who have not achieved adequate results with lifestyle modifications
Absolute Contraindications
- Pregnancy and breastfeeding
- Personal or family history of medullary thyroid carcinoma
- Multiple endocrine neoplasia syndrome type 2
- Acute or chronic pancreatitis
Administration Methods
Dosage Schedule
Both drugs are administered via weekly subcutaneous injection. The treatment includes:
- Titration phase: gradual dosage increase to minimize side effects
- Maintenance dose: reached after 4-8 weeks
- Continuous monitoring: periodic evaluation of efficacy and tolerability
Injection Technique
Pre-filled pens allow for simple self-administration. Recommended injection sites are:
- Abdomen (avoiding the periumbilical area)
- Anterior thigh
- Upper arm
Side Effects and Management
Common Adverse Reactions
The most frequently reported side effects in clinical studies include:
- Gastrointestinal (30-40% of patients): nausea, vomiting, diarrhea, constipation
- Systemic: headache, fatigue
- Local: injection site reactions
Minimization Strategies
To reduce the incidence of side effects:
- Slow dosage titration
- Dietary modifications (small, frequent meals)
- Adequate hydration
- Possible temporary symptomatic therapy
Economic Aspects and Accessibility
The National Health Service Situation
Currently in Italy:
- Mounjaro: reimbursed by the SSN since February 23, 2025, for type 2 diabetes mellitus in adults (with a therapeutic plan), but NOT for weight loss
- Wegovy: not reimbursed for obesity
- Semaglutide (other brand names): reimbursable with a therapeutic plan for type 2 diabetes mellitus
For the specific indication of weight loss, both drugs fall into Class C and are therefore entirely paid for by the patient. This situation represents a significant barrier to access for many patients who could benefit from obesity treatment.
Economic Considerations
The required economic investment is substantial:
- Annual cost: €2,640-7,476
- Duration of treatment: often exceeding 12 months
- Need for maintenance to avoid weight regain
Long-Term Efficacy and Sustainability
Maintenance of Results
Follow-up studies highlight that:
- Discontinuation of treatment generally leads to weight regain
- Maintenance at a reduced dosage can be an effective strategy
- Combination with permanent lifestyle changes is fundamental
The Role of Lifestyle
Weight loss drugs are most effective when integrated into a program that includes:
- Sustainable dietary changes
- Regular physical activity
- Psychological support when necessary
- Continuous medical monitoring
Important Warnings
Purchase and Prescription
It is essential to emphasize that:
- These drugs require a medical prescription
- Online purchase is illegal and potentially dangerous
- Counterfeit products may contain harmful substances
- Only authorized pharmacies can dispense these medications
Inappropriate Use
Mounjaro and Wegovy are not indicated for:
- Cosmetic weight loss in normal-weight individuals
- Use in adolescents (except in rare indications)
- Patients with eating disorders
- Rapid weight loss situations before an event
Future Perspectives
Research and Development
The obesity drug sector is rapidly evolving:
- New molecules in the testing phase
- Oral formulations in development
- Combination therapies
- Personalized approaches based on biomarkers
Possible Regulatory Evolutions
Italian scientific societies are working toward:
- Recognition of obesity as a chronic pathology
- Inclusion of certain drugs in the LEA (Essential Levels of Care)
- Development of standardized diagnostic-therapeutic pathways
Conclusions
Mounjaro and Wegovy represent a major innovation in the pharmacological treatment of obesity. Their efficacy is supported by solid scientific evidence, but their use must be carefully evaluated on a case-by-case basis, considering:
- Actual clinical necessity
- The economic sustainability of the treatment
- The patient’s motivation for change
- The presence of contraindications
It is essential that the decision to undertake this therapeutic path is made in collaboration with an expert physician, who can evaluate all clinical aspects and guide the patient toward the most appropriate choice.
The future challenge will be to make these treatments accessible to all those who have a real clinical need, overcoming current economic barriers and ensuring a fair and sustainable approach to obesity management in our country.
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