Tirzepatide: Effective Treatment for Weight Loss

Tirzepatide represents a significant advance in the treatment of obesity and overweight with comorbidities, standing out for its clinically proven efficacy in promoting substantial and sustainable weight loss. Although it is a medication, its mechanism of action mimics the body's natural hormones, making the weight loss process more aligned with the body's physiological responses.

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What is Tirzepatide? A Dual-Action and Innovative Solution

Tirzepatide is an injectable medication that acts as a dual agonist of GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptors. This combined action on two hormone receptors differentiates it from other treatments that focus only on GLP-1, giving it superior efficacy.

Trade Names:

In Brazil, it is currently marketed under the name Mounjaro™ for the treatment of Type 2 Diabetes.

In the United States, it was approved under the name Zepbound™ specifically for weight management in obese and overweight individuals with comorbidities. The expectation is that this indication will eventually reach Brazil.

How does tirzepatide work for effective weight loss?

The effectiveness of tirzepatide derives from its multifaceted action, which mimics and amplifies the function of hormones naturally produced by the intestine after meals. This results in:

Enhanced Appetite and Satiety Control:

By activating GIP and GLP-1 receptors in the brain, Tirzepatide reduces feelings of hunger and intense food cravings ("food noise").

It increases the feeling of satiety (fullness) after meals, making the individual feel satisfied with smaller portions and for a longer period.

Delayed Gastric Emptying:

It slows down the rate at which food leaves the stomach, prolonging the feeling of fullness and contributing to reduced calorie intake throughout the day.

Improved Metabolic Response and Insulin Sensitivity:

Tirzepatide increases insulin secretion by the pancreas in a glucose-dependent manner (when blood sugar is high), which helps control glucose levels.

It improves the body's sensitivity to insulin, allowing cells to use glucose more efficiently and reducing fat storage.

Recent studies indicate that tirzepatide may also increase fat oxidation (burning fat for energy) and, crucially, may mitigate the metabolic slowdown that typically occurs during weight loss. This facilitates the maintenance of the lost weight.

Preservation of Lean Muscle Mass:

A vital aspect of its effectiveness is its ability to promote weight loss that is predominantly fat mass, with a notable preservation of muscle mass. This is fundamental for long-term metabolic health and for maintaining an active metabolism.

Proven Results: The Effectiveness of Tirzepatide in Numbers

The effectiveness of tirzepatide for weight loss is extensively documented by rigorous Phase 3 clinical studies (the SURMOUNT program), widely recognized by the scientific and medical community in Brazil and worldwide.

Average Substantial Weight Loss:

In the SURMOUNT-1 study, participants without Type 2 diabetes achieved an average weight loss ranging from 15% to 22.5% from their baseline body weight over 72 weeks (approximately 1 year and 6 months) using the highest doses (10mg and 15mg). This translates to an average reduction of 16kg to over 24kg.

The SURMOUNT-5 study, which directly compared tirzepatide with semaglutide (another effective drug), demonstrated that tirzepatide led to an average weight loss of 20.2% of body weight, significantly greater than that observed with semaglutide.

Predominant Fat Reduction: Clinical studies confirm that weight loss is primarily composed of fat mass, with good maintenance of lean mass (muscle).

Long-Term Sustainability: Long-term analyses, such as those presented at the European Congress on Obesity (ECO) in May 2025, indicate that tirzepatide can promote clinically significant and sustainable weight loss for at least 3 years. Approximately two-thirds of participants were able to maintain most of the weight lost during this period.

Results in “Real Life”: Data from “real-world” use in the US have corroborated the effectiveness of clinical trials, with patients achieving robust average weight loss and high rates of adherence to treatment.

For Whom is Tirzepatide an Effective Treatment? Criteria and Access in Brazil

Tirzepatide is a prescription medication and should not be used without professional supervision. In Brazil, its currently approved indication by ANVISA is for the treatment of Type 2 Diabetes. However, it is common for doctors, after careful evaluation, to prescribe it "off-label" (outside the formal indication in the package insert) for patients with obesity or overweight and comorbidities, if they consider it clinically appropriate.

Eligibility Criteria (generally considered, based on internationally approved guidelines for weight):

Adults with a BMI (Body Mass Index) of 30 kg/m² or higher (obesity).

Adults with a BMI of 27 kg/m² or higher (overweight) who have at least one weight-related comorbidity, such as:

Hypertension (high blood pressure)

Type 2 Diabetes (already formally approved)

Dyslipidemia (high cholesterol and triglycerides)

Obstructive sleep apnea.

Thorough Medical Evaluation: Before any prescription, the doctor will conduct a complete medical history, physical examination, and often laboratory tests (blood) to assess your overall health, family history, contraindications (such as a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia type 2 – MEN2, which are absolute contraindications) and discuss the risks and benefits of treatment.

What is the treatment with tirzepatide like? Administration and Dosage

Tirzepatide is administered via weekly subcutaneous injections, which the patient can administer at home in the thigh, abdomen, or upper arm using a pre-filled pen.

Gradual Dose Escalation (Titration): Treatment usually begins with the lowest dose (e.g., 2.5 mg) and is gradually increased every 4 weeks, under medical supervision. This titration process is crucial to allow the body to adapt to the medication and to minimize side effects, especially gastrointestinal ones.

Side Effects and Management for Effectiveness

Like all medications, tirzepatide can cause side effects. Most are gastrointestinal in nature, tend to be more pronounced at the beginning of treatment or with increased doses, and generally decrease as the body adapts.

Common Side Effects (Gastrointestinal):

Nausea (most common)

Diarrhea or constipation

Vomiting

Abdominal pain and swelling

Belching (burping) and flatulence

Heartburn or acid reflux.

Less Common/More Serious Side Effects (Require Immediate Medical Attention): Pancreatitis (inflammation of the pancreas), acute kidney injury, gallbladder disease, severe allergic reactions.

Important Warning: Tirzepatide (and other GLP-1 agonists) has a package insert warning about the potential risk of thyroid C-cell tumors (including medullary thyroid carcinoma – MTC), observed in rodent studies. Therefore, it is contraindicated in patients with a personal or family history of MTC or MEN2.

The doctor who prescribes Tirzepatide will advise on how to manage the most common side effects, often with adjustments to diet (smaller meals, avoiding fats) and hydration.

Price and Access to Tirzepatide in Brazil

Tirzepatide is a high-cost medication in Brazil. The price can vary depending on the dosage and the pharmacy.

Average Cost: In 2024, the price of a box containing 4 pens (for 1 month of treatment) of Mounjaro (Tirzepatide) could range from R$ 900 to R$ 1,500 or more, depending on the dose and place of purchase. These values are for reference only and may be adjusted in 2025.

Access: The medication is obtained at pharmacies upon presentation of a medical prescription. Coverage by health insurance plans may vary and generally requires prior approval and proof of use for the approved indications.

Tirzepatide and Healthy Lifestyle: Maximizing Effectiveness

The medical community in Brazil emphasizes that tirzepatide is a powerful tool, but not a standalone solution for sustainable weight loss. Its effectiveness is maximized when combined with a holistic approach that includes:

Balanced and Low-Calorie Diet: Medication facilitates adherence to a healthy diet, reducing hunger and cravings. Working with a nutritionist is essential for a personalized and sustainable meal plan.

Regular Physical Activity: Incorporating physical exercise (cardio and strength training) complements the medication's action, contributing to fat burning, preservation of muscle mass, and improvement in overall health.

Behavioral Support: Addressing emotional triggers for eating, managing stress, and optimizing sleep quality are crucial for building lasting healthy habits.

Ongoing Medical Monitoring: Regular visits to the doctor are essential to monitor progress, adjust doses, manage side effects, and ensure that treatment is aligned with the patient's overall health.

In conclusion, tirzepatide is an effective and scientifically proven treatment for weight loss, working by aligning the body's biological processes with the goal of slimming. In Brazil, for eligible patients, it represents a promising and transformative option when used under strict medical supervision and as part of a comprehensive weight management program.