Zepbound

Zepbound is the brand name under which Eli Lilly sells tirzepatide in the United States for the treatment of obesity. It was approved by the FDA in November 2023 and has been on the US market since early 2024. It contains the same active substance as Mounjaro, in the same dose steps (2.5 to 15 mg, weekly subcutaneous injection).

A frequently asked question: why two different brands for the same medicine? The answer lies in regulatory and commercial strategy. In the US, Mounjaro was originally registered for type 2 diabetes. When Eli Lilly wanted to launch the obesity indication, they deliberately chose to do so under a separate brand name (Zepbound), so that insurers and patients can clearly distinguish between the two indications. In Europe, the EMA follows a different model: one brand (Mounjaro) for both indications.

For the medical mechanism, dosing and side effects, please see our page on tirzepatide. Patient experiences, reimbursement and practical information for patients in the Netherlands can be found on the Mounjaro page.

Zepbound is injected subcutaneously once a week via a prefilled KwikPen. The dose is increased gradually to minimise nausea and other gastrointestinal complaints. This protocol is identical to Mounjaro in the Netherlands.

Standard titration schedule:

• Weeks 1-4: 2.5 mg/week (starting dose, no therapeutic effect — tolerance build-up only)
• Weeks 5-8: 5 mg/week (first therapeutic dose)
• Weeks 9-12: 7.5 mg/week (optional increase)
• Weeks 13-16: 10 mg/week
• Weeks 17-20: 12.5 mg/week
• Week 21+: 15 mg/week (maximum maintenance dose)

Injection sites rotate between the abdomen, thigh and upper arm. The day of the week can be flexible, as long as there are at least 72 hours between two injections. If you miss a dose: inject within 4 days, otherwise wait for the next scheduled day.