From the Guidelines
Tirzepatide is most effective for weight loss at a dosage of 15 mg injected subcutaneously once weekly, as it has been shown to result in a mean weight loss of 20.9% at 72-week follow-up 1. The recommended dosage of tirzepatide for weight loss typically starts at a lower dose and gradually increases to minimize side effects.
- The dosage starts at 2.5 mg or 5 mg injected subcutaneously once weekly for the first month,
- then increases to 10 mg weekly,
- and potentially up to 15 mg weekly, depending on response and tolerability 1. Key points to consider when using tirzepatide for weight loss include:
- Administering injections on the same day each week,
- rotating injection sites between the abdomen, thigh, or upper arm,
- common side effects such as nausea, vomiting, and diarrhea, which typically improve over time,
- the importance of using tirzepatide alongside lifestyle modifications including diet and exercise for maximum effectiveness 1. It is also crucial to note that patients with a history of certain conditions, such as pancreatitis, medullary thyroid cancer, or multiple endocrine neoplasia syndrome type 2, should avoid this medication. Tirzepatide works by activating both GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptors, which reduces appetite, slows gastric emptying, and improves metabolic function, making it an effective treatment option for weight loss, as demonstrated by its association with greater weight loss compared to other medications, such as semaglutide and liraglutide 1.
From the Research
Dosage of Tirzepatide for Weight Loss
The recommended dosage of tirzepatide for weight loss is as follows:
- 5 mg once weekly, resulting in a mean percentage change in body weight of -15.0% 2
- 10 mg once weekly, resulting in a mean percentage change in body weight of -19.5% 2
- 15 mg once weekly, resulting in a mean percentage change in body weight of -20.9% 2
Efficacy of Different Dosages
The efficacy of different dosages of tirzepatide for weight loss is:
- A dose-dependent weight loss was observed, with higher doses resulting in greater weight loss 3
- The 10 mg and 15 mg doses resulted in significant reductions in body weight, with a mean percentage change in body weight of -19.5% and -20.9%, respectively 2
- The 5 mg, 10 mg, and 15 mg doses also significantly reduced body mass index and waist circumference 3
Comparison with Other GLP-1 Receptor Agonists
Tirzepatide has been compared to other GLP-1 receptor agonists, including semaglutide and liraglutide:
- Weekly tirzepatide 10 and 15 mg resulted in more weight loss than weekly semaglutide 2.4 mg, daily semaglutide 0.4 mg, or liraglutide 3 mg 4
- Tirzepatide and weekly semaglutide demonstrated comparable results, but with significantly higher odds of achieving ≥5%-20% weight loss compared with liraglutide 4
Safety Profile
The safety profile of tirzepatide is:
- Gastrointestinal side effects were the most frequently reported adverse events, which were generally mild-to-moderate and transient 3
- Adverse events caused treatment discontinuation in 4.3%, 7.1%, 6.2%, and 2.6% of participants receiving 5-mg, 10-mg, and 15-mg tirzepatide doses and placebo, respectively 2