Weight-Loss Medications and Medical Care: An Educational Overview

Overview

This page is an educational overview of medical weight care. It does not tell you whether to use any treatment. Decisions about medicines belong with a prescriber who knows your health history. Evidence labels: established recommendation, promising but limited, mixed, insufficient evidence.

Who might be offered medicines

NIDDK says prescription weight management medicines are meant for people with health problems related to overweight or obesity. A health care professional may prescribe one for an adult with a BMI of 30 or greater, or a BMI of 27 or greater with weight-related problems such as high blood pressure or type 2 diabetes. [1] NHS says medicines are usually prescribed alongside diet and lifestyle advice and that support should be offered after you stop. [2] Medicines do not replace healthy eating and physical activity. [1] NIDDK says they are not for everyone with a high BMI and should never be taken only to improve how you look. [1]

How they work

NIDDK says some medicines help you feel less hungry or full sooner, and others make it harder to absorb fat from food. [1] The injectable GLP-1 (glucagon-like peptide-1) medicines, such as semaglutide and liraglutide, mimic a hormone that targets brain areas that regulate appetite and food intake; tirzepatide mimics two hormones, GIP and GLP-1. [1] NHS says semaglutide works for weight loss by reducing appetite and helping you feel fuller for longer. [3] The same medicine is sold under different brand names for type 2 diabetes and for weight management. [3]

What the research shows

These are average results from trials. Individual results vary, and trials often exclude people with certain conditions. NHS advises not stopping semaglutide suddenly. [3]

Safety and side effects

• NHS lists common semaglutide side effects as nausea and vomiting, constipation, diarrhea, tiredness, injection site reactions and hair loss. [3]
• Serious but rare effects NHS lists include allergic reaction (swollen throat or tongue, difficulty breathing), worsening diabetic retinopathy, inflamed pancreas (severe stomach or back pain that does not go away), low blood sugar and sudden loss of vision. [3] NHS advises calling NHS 111 in the UK if you think you may be having serious side effects. [3] In the US, if someone has a swollen throat or difficulty breathing, call 911.
• NIDDK says some people on certain weight-loss medicines have reported suicidal thoughts or actions, and the FDA continues to look into whether the medicines cause this. [1] If you have such thoughts, call or text 988 in the US.
• Do not use these medicines in pregnancy or when planning pregnancy; NHS says semaglutide is not used in pregnancy and should be stopped at least 2 months before trying to conceive. [3][1]
• GLP-1-type medicines are not suitable for people with a personal or family history of medullary thyroid cancer or MEN 2, according to NIDDK. [1]
• Do not combine weight-loss medicines with other weight-loss products unless a health care professional prescribes it. [1] See How interactions work.

Unapproved and compounded copies

The FDA warns that unapproved versions of semaglutide and tirzepatide do not undergo FDA review for safety, effectiveness and quality; it recommends compounded drugs be used only when medical needs cannot be met by an approved drug, and warns about dosing errors, fraudulent labels and mishandled storage. [8] Red flags include no prescription requirement and prices that seem too good to be true. [8]

Other medical care

• Nutrition counseling: NIDDK says a health care professional may refer you to a registered dietitian or a specific program. [9]
• Structured programs: NHS lists 1 to 1 coaching, cognitive behavioral therapy, group support and online classes. [2]
• Metabolic and bariatric surgery: NHS says it may be offered at a BMI of 40 or over, or 35 or over with other conditions that could improve, with lower thresholds for some backgrounds; recovery is usually 3 to 4 weeks. [2] NIDDK says some groups recommend it at lower BMI if other conditions are present. [10]
• Devices: Long-term risks and benefits are not yet known. [10]
• Insurance: Some, but not all, US plans cover these medicines. [1]

When to get help

Talk to your clinician or pharmacist before starting, changing or stopping any weight-loss medicine, and if you have side effects. If you have eating-disorder symptoms, tell your prescriber; NIDDK says one medicine (naltrexone-bupropion) is not for people with anorexia or bulimia. [1] See Weight and metabolism safety, Overweight and obesity, and Medicines that can change weight.