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Medicines for weight: who they are for, how they work, the seven medicines, side effects, how long, and cost
For anyone who has been offered, or is wondering about, a prescription medicine for weight, such as semaglutide (Wegovy) or tirzepatide (Zepbound), and for the people beside them. It passes on, by name, what the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK, part of the NIH) says: who the medicines are meant for, how they work and how much they help, NIDDK’s table of the seven medicines approved for long-term use and who should not take each, side effects and safety, how long to take one, what happens when you stop, and insurance. It builds the words to say to a health care professional or pharmacist, and prints a card. Nothing is saved.
Right now
- Are you in danger right now? Call 911; you do not need to be sure (ours: NIDDK’s page names no 911).
- Thoughts of suicide or of harming yourself? Call or text 988, any hour (ours). NIDDK says some people on certain weight-loss medicines have reported suicidal thoughts or actions: tell your health care professional right away. See also When eating has become a fight.
More help
- On this site: Eating well and moving more · Changing your habits · Prediabetes · Sleep apnea.
- Medicines: My medicines list · When you can’t afford your medicine.
- When it is hard: When eating has become a fight · When you need a doctor and can’t pay.
- Getting ready: Get ready for your appointment. In a crisis: Help right now (988, 911). All our free tools.
Your heart, blood pressure, blood sugar, thyroid or blood, and not sure this is the right page? The pages on this site for a heart attack or stroke, blood pressure, AFib, heart failure, cholesterol, diabetes and prediabetes, the thyroid, anemia, sickle cell and menopause, on one list.
Other guides on this site that go with this page
Free to read. We chose these ourselves; no professional did. Each guide was written with AI and has not been reviewed by a professional. They are general information, not advice.
- When it’s high blood pressure: what the numbers mean, a very high reading and when to call 911, checking at home, medicines, salt and food, pregnancy, and what to ask: high blood pressure: what the two numbers mean, what to do with a very high reading and when it is a 911 call, how to get a true reading, the kinds of medicine, and salt.
This page and its wording were written with AI (Claude) for Scarlet Beast (our AI policy). No doctor, nurse or pharmacist has reviewed it. The facts were read on October 19, 2026 on NIDDK’s (NIH) page Prescription Medications to Treat Overweight & Obesity (last reviewed June 2024) and its Spanish twin. Medicines and approvals change: newer medicines or uses may have come since that page was reviewed, so ask a health care professional or pharmacist what is true today. The numbers (a BMI of 30 or greater, or 27 or greater with a weight-related health problem; four medicines approved from age 12 and one from age 6; 3% to 12% more weight lost after 1 year than a lifestyle program alone; 5% to 10% that may improve health; most loss in the first 6 months; 5% after 12 weeks on the full dose; at least 150 minutes of moderate activity and 2 days of muscle-strengthening a week, maybe more than 300 minutes; more than 4 in 10 adults) and the table of medicines are NIDDK’s, and we add none. Ours: 911 and 988 (NIDDK names neither on this page); our eating disorders, my medicines, medicine costs, low-cost care, habits, eating well, prediabetes and sleep apnea pages; that the choice is yours with a professional, and you never need a medicine, or to want to lose weight, to deserve care; to talk with a professional before you stop; the questions; the links to our other pages; and the order of the steps. What we left out: NIDDK’s section on clinical trials, its references, and its links to other sites (DRUGS@FDA, the Physical Activity Guidelines), which we name. There are no prices on NIDDK’s page, and none here. Nothing you tick or type here is saved or sent.