Tirzepatide (Zepbound) for weight loss: what it is, risks, and what to ask a clinic

Tirzepatide is a prescription injection. Sold as Zepbound, it is FDA-approved for weight management in adults, alongside a reduced-calorie diet and more physical activity.¹

Here is what the label says about its uses, the boxed warning, the side effects seen in trials and who shouldn't use it, followed by the FDA's warnings about copies. It gives no dose. Whether it is right for you is a question for a doctor who knows your health.

What it is

Tirzepatide acts on two receptors, GIP and GLP-1, which the label describes as a GIP receptor and GLP-1 receptor agonist.¹ The label lists two uses in adults, each in combination with a reduced-calorie diet and increased physical activity.¹

The label says using it with any other tirzepatide product or any GLP-1 receptor agonist isn't recommended. It also says safety and effectiveness haven't been established in pediatric patients.¹ For how it compares with semaglutide, see our comparison page.

Who should not use it

The label has a boxed warning, its strongest kind. In rats, tirzepatide caused thyroid C-cell tumors. It is unknown whether it does in humans.¹ The label says Zepbound must not be used by people with a personal or family history of medullary thyroid carcinoma or the genetic condition MEN 2, or who have had a serious allergic reaction to tirzepatide or anything in the product.¹

Tell a prescriber your full history before any GLP-1 drug, including your family's.

On pregnancy, the label says Zepbound may cause fetal harm and that it should be stopped when a pregnancy is recognized.¹ Tell your prescriber if you are pregnant, planning a pregnancy or breastfeeding. The label also has an interaction warning about oral hormonal contraceptives, so tell your prescriber what you use.¹

Side effects seen in trials

The label pools two placebo-controlled trials of 2,519 adults treated for up to 72 weeks. Nausea was reported by 25% to 29% across the three Zepbound groups, against 8% with placebo. Diarrhea was 19% to 23% against 8%, vomiting 8% to 13% against 2%, and constipation 11% to 17% against 5%.¹ Severe gastrointestinal reactions were reported by 1.7% to 3.1% of people on Zepbound and 1% on placebo.¹

The label says rates from one drug's trials can't be directly compared with those of another drug, and may not reflect what happens in practice.¹

The label also warns that food or liquid can enter the lungs under general anesthesia or deep sedation, and tells patients to inform providers of any planned procedure. It says never to share a pen between people, even if the needle is changed.¹

Compounded tirzepatide

Some clinics sell tirzepatide made by a compounding pharmacy, not the approved Zepbound. The FDA says compounded drugs are not FDA-approved and that it does not review them for safety, effectiveness or quality before they are marketed. It says they should be used only when a patient's medical needs can't be met by an approved drug.² It has reports of dosing errors with compounded semaglutide and of fraudulent semaglutide and tirzepatide products with false labels.²

The FDA's advice is to get a prescription from your doctor and fill it at a state-licensed pharmacy.² Our guide to choosing a weight loss clinic covers its warning signs.

At the clinics we list

3,194 of the 7,475 med spas we list offer weight loss. That doesn't say which drug, who prescribes it or whether it is compounded, so ask.³

Here is what to bring to a consultation.

Cost

We don't give prices on this page. Insurance and payment are covered in our guide to paying for med spa treatments.

Common questions