How long does it take for Zepbound to work?
In clinical studies submitted to the FDA for approval, patients lost weight during the first 4 weeks of taking Zepbound (tirzepatide). How quickly you lose weight on Zepbound depends on various factors, including your starting weight, the dose you are taking, diet, and physical activity level.
What is Zepbound used for?
Zepbound is a glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist. It’s injected under the skin once a week in addition to diet and exercise for long-term weight management in adults with a body mass index (BMI) of:
- 30 kg/m2 or more, or
- 27 kg/m2 or more and at least one weight-related health condition (e.g., high blood pressure, type 2 diabetes, obstructive sleep apnea)
Does Zepbound work immediately?
You won’t notice weight-loss effects from Zepbound right away. After injecting a dose of Zepbound, it reaches maximum levels in your body between 8 and 72 hours. This suggests that the medication can start to work the same day after taking a dose to suppress your appetite. However, your healthcare provider will need to slowly titrate your dose up to the most effective dose of Zepbound. They will start you on a low dose (2.5 mg) for the first 4 weeks of treatment. This dose is meant to get your body used to the medication. After 4 weeks, your dose will be raised to 5 mg once weekly. The recommended maintenance doses of Zepbound are 5 mg, 10 mg, or 15 mg.
Zepbound works by affecting your appetite, which helps you eat less calories. Therefore, it will take some time to lose weight. The amount of time it takes to lose weight while taking Zepbound will be different for each individual person. This is because how quickly you lose weight from Zepbound depends on factors like eating habits and how much physical activity you are getting.
Related questions
- Zepbound vs. Mounjaro: Comparison Guide for Weight Loss and Diabetes Treatment
- Why am I not losing weight on Mounjaro?
- Ozempic Mounjaro Wegovy & Zepbound: Weight Loss Compared
When is the best time to take the Zepbound shot?
According to the manufacturer, Zepbound can be injected at any time of the day. The time of day shouldn’t affect how well the medication works for you because it has a long half-life, which means it stays in your body for a long time. Make sure to inject it once a week on the same day every week. You can inject Zepbound with or without food.
References
Jastreboff, A. M., et. al. (2022). Tirzepatide Once Weekly for the Treatment of Obesity. In: The New England Journal of Medicine. DOI: https://doi.org/10.1056/nejmoa2206038
Jensen, T. L. ,et. Al. (2024). The Body weight Reducing Effects of Tirzepatide in People with and without Type 2 Diabetes: A Review on Efficacy and Adverse Effects. In: Patient Preference and Adherence. DOI: https://doi.org/10.2147%2FPPA.S419304
Zepbound [package insert]. (Updated March 2024). Eli Lilly and Company. Accessed 07/12/2024 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b
Read next
How much is Zepbound with or without insurance?
Zepbound may cost $25 if you have insurance, or without insurance, Zepbound can cost $349 for a 2.5mg vial and $499 for a 5mg vial Continue reading
Which GLP-1 drug is best for weight loss?
The most effective GLP-1 drug for weight loss currently (as of mid-2025) is tirzepatide, marketed under the names Zepbound (for weight loss) and Mounjaro (for diabetes).
Continue reading
Can you get tirzepatide from a compounding pharmacy?
Some pharmacies or clinics may supply compounded versions of medicines like tirzepatide (Mounjaro, Zepbound) and semaglutide (Ozempic, Wegovy) to patients, but the FDA has issued safety warnings about this practice. Concerns have risen over active ingredients, side effects and labeling of these compounded products. Continue reading
See also:
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Drug information
- Zepbound Information for Consumers
- Zepbound prescribing info & package insert (for Health Professionals)
- Side Effects of Zepbound (detailed)
- Zepbound user reviews (412)
Related support groups
- Zepbound (24 questions, 30 members)
- Weight Loss (Obesity/Overweight) (865 questions, 1,513 members)