Question: What are overweight and obesity?
Answer: Health care professionals use the Body Mass Index (BMI), a measure of your weight in relation to your height, to define overweight and obesity.

People who have a BMI between 25 and 30 are considered to be overweight. Obesity is defined as having a BMI of 30 or greater. You can calculate your BMI to learn if you are overweight, have obesity, or have severe obesity, which may increase your risk of health problems. Your health care professional can assess your individual risk caused by your weight.

If you are struggling with your weight, a healthy eating plan and regular physical activity may help you lose weight and keep it off over the long term. If these lifestyle changes are not enough to help you lose weight or maintain your weight loss, your health care professional may prescribe medications as part of your weight-control program.
Question: How common are overweight and obesity?
Answer: Obesity is a chronic disease that affects more than 4 in 10 adults in the United States, and nearly 1 in 10 Americans have severe obesity.1
Question: How do weight management medications work?
Answer: Prescription medications to treat overweight and obesity work in different ways. For example, some medications may help you feel less hungry or full sooner. Other medications may make it harder for your body to absorb fat from the foods you eat.
Question: Who might benefit from weight management medications?
Answer: Weight management medications are meant to help people who have health problems related to overweight or obesity. Health care professionals use BMI to help decide whether you might benefit from weight management medications. Your health care professional may prescribe a medication to treat your overweight or obesity if you are an adult with

a BMI of 30 or greater
a BMI of 27 or greater, and you have weight-related health problems such ashigh blood pressureortype 2 diabetes

Weight management medications aren’t for everyone with a high BMI. If you are overweight or have obesity, you might be able to lose weight with a lifestyle program that changes your behaviors and improves your eating and physical activity habits. A lifestyle program may also address other things that cause you to gain weight, such as eating triggers and not getting enough sleep.
Question: Can children or teenagers take weight management medications?
Answer: The U.S. Food and Drug Administration (FDA) has approved four weight management medications for children ages 12 and older: orlistat (Xenical),2 liraglutide (Saxenda),3 phentermine-topiramate (Qsymia),4 and semaglutide (Wegovy).5,6 A fifth prescription medication, setmelanotide (IMCIVREE),7 is approved by the FDA for children ages 6 years and older who have rare genetic disorders causing obesity.
Question: Can medications replace physical activity and healthy eating habits as a way to lose weight?
Answer: Medications don’t replace physical activity or healthy eating habits as a way to lose weight. Studies show that weight management medications work best when combined with a lifestyle program. Ask your health care professional about lifestyle treatment programs for weight management that will work for you.

Weight management medications don’t replace physical activity and healthy eating habits.
Question: What are the benefits of using prescription medications to lose weight?
Answer: When combined with lifestyle and behavior changes, including healthy eating and increased physical activity, prescription medications help some people lose weight and maintain weight loss. On average, after 1 year, adults who take prescription medications as part of a lifestyle program lose 3% to 12% more of their starting body weight than people in a lifestyle program who do not take medication. Less information is available for children ages 12 and over, but ranges appear to be similar.

Research shows that some people taking prescription weight management medications lose 10% or more of their starting weight.8,9 Results vary by medication and by person, with more than half of participants losing 10% or more of their starting weight with some medications.

Weight loss of 5% to 10% of your starting body weight may help improve your health by lowering blood sugar, blood pressure, and triglyceride levels. Losing weight also can improve some other health problems related to overweight and obesity, such as joint pain and sleep apnea. Most weight loss takes place within the first 6 months of starting the medication.
Question: What are the concerns about using prescription medications to lose weight?
Answer: Experts are concerned that, in some cases, the side effects of prescription medications that treat overweight and obesity may outweigh the benefits. For this reason, never take a weight management medication only to improve the way you look. In the past, some weight management medications were linked to serious health problems, and they were removed from U.S. markets.

Possible side effects vary by medication and how it acts on your body. Most side effects are mild and most often improve if you continue to take the medication. Rarely, serious side effects can occur.

Tips for taking weight management medication

Follow your health care professional’s instructions about weight management medications.
Buy your medication from a pharmacy or online distributor approved by your health care professional.
Only take weight management medication to support your healthy eating and physical activity program.
Know the side effects and warnings before taking any medication.
If you are not losing weight after 12 weeks on the full dose of your medication, ask your health care professional whether you should stop taking it.
Talk with your health care professional about any other medications you are taking, including supplements and vitamins, when considering weight management medications.
Never take weight management medications during pregnancy or if you are planning a pregnancy.
Question: Which weight management medication might work for me?
Answer: Choosing a medication to treat overweight or obesity is a decision between you and your health care professional. Important factors to consider include

the likely benefits of weight loss
the medication’s possible side effects
your current health issues and other medications
your family’s medical history
cost
Question: How long will I need to take weight management medication?
Answer: How long you will need to take weight management medication depends on whether the drug helps you lose weight and keep it off and whether you experience serious side effects.

If you have lost enough weight to improve your health and are not experiencing serious side effects, your health care professional may advise you to stay on the medication indefinitely. If you do not lose at least 5% of your starting weight after 12 weeks on the full dose of your medication, your health care professional will probably advise you to stop taking it. Your health care professional may also

change your treatment plan or consider using a different weight management medication
have you try different lifestyle, physical activity, or eating programs
change your other medications that might be causing weight gain
refer you to a bariatric surgeon  to see ifweight-loss (bariatric) surgerymight be an option for you

Because obesity is a chronic disease, you may need to continue your new eating and physical activity habits and other behaviors for years—or even a lifetime—to improve your health and maintain a healthier weight.
Question: Will I regain some weight after I stop taking weight management medication?
Answer: You probably will regain some weight after you stop taking weight management medication. Developing and maintaining healthy eating habits and increasing physical activity may help you regain less weight or keep it off.

Federal physical activity guidelines (PDF, 14.5 MB)  recommend at least 150 minutes a week of moderate-intensity aerobic activity and at least 2 days a week of muscle-strengthening activities. You may need to do more than 300 minutes of moderate-intensity activity a week to reach or maintain your weight-loss goal.
Question: Will insurance cover the cost of weight management medication?
Answer: Some, but not all, insurance plans cover medications that treat overweight and obesity. Contact your insurance provider to find out if your plan covers these medications.
Question: What medications are available to treat overweight and obesity?
Answer: The table below lists prescription drugs approved by the FDA for chronic weight management. The FDA has approved six of these drugs—orlistat (Xenical, Alli), phentermine-topiramate (Qsymia), naltrexone-bupropion (Contrave), liraglutide (Saxenda), semaglutide (Wegovy), and tirzepatide (Zepbound)—for long-term use. Four of these drugs are approved for adults and children ages 12 and older. Another approved drug, setmelanotide (IMCIVREE), is limited to people who have been diagnosed with one of four specific rare genetic disorders, which must be confirmed by genetic testing. You can keep taking these medications as long as you are benefiting from treatment and not experiencing serious side effects.

Some weight management medications that curb appetite, such as phentermine, are approved by the FDA only for use for a few weeks. Although some health care professionals prescribe them for longer periods, not many research studies have looked at how safe and effective they are for long-term use.

These medications have side effects, some of which could be severe. Before taking any medication to treat obesity, talk with your health care professional about the possible risks and benefits.

Ask your health care professional if you have medical conditions that could increase your risk of developing health problems when taking weight-loss medications.
Weight-loss medications may have harmful interactions with other medications you are taking. Discuss any prescribed medications, over-the-counter medications, or herbal products you take. Do not combine weight-loss medications with other products intended for weight loss, unless prescribed by a health care professional.
People taking certain weight-loss medications have reported having suicidal thoughts or actions, and theFDAcontinues to look into whether this is caused by the medication.
If you are pregnant or planning to become pregnant, you should not take weight-loss medications, as they may harm the fetus. Weight-loss medications are not recommended if you are breastfeeding.
Before taking a weight-loss medication, tell your doctor about any allergies or sensitivities you may have.

The table below includes limited information about weight-loss medications. Side effects and other reactions to weight management medications are possible.10 For more information, visit the FDA drug database, DRUGS@FDA.

Prescription medications approved for long-term use to treat overweight and obesity
Question: How do health care professionals use prescription medications “off-label” to treat overweight and obesity?
Answer: Sometimes health care professionals use medications in a way that’s different from what the FDA has approved. That’s called “off-label” use. By choosing an off-label medication to treat overweight and obesity, your health care professional may prescribe

a drug approved for treating a different medical problem
two or more drugs at the same time
a drug for a longer time period than approved by the FDA

You should feel comfortable asking whether your health care professional is prescribing a medication that is not approved for treating overweight and obesity. Before using a medication, learn all you need to know about it.
Question: What other medications for weight loss may be available in the future?
Answer: Researchers are currently studying several new medications and combinations of medications in animals and people. Researchers are working to identify safer and more effective medications to help people who are overweight or have obesity lose weight and maintain a healthy weight for a long time.

Future drugs may use new strategies, such as

regulating several guthormonesat the same time
targeting specificgenesthat cause obesity
allowing people to lose body fat without losing muscle during weight loss
changingbacteriain the gut to control weight
Question: Clinical Trials for Prescription Medications to Treat Overweight and Obesity
Answer: NIDDK conducts and supports clinical trials in many diseases and conditions, including overweight and obesity. The trials look to find new ways to prevent, detect, or treat disease and improve quality of life.

What are clinical trials for prescription medications to treat overweight and obesity?

Clinical trials—and other types of clinical studies—are part of medical research and involve people like you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.

Researchers are studying many aspects of prescription medications to treat overweight or obesity, such a

the effect of the FDA-approved medication liraglutide (Saxenda, Victoza) on weight loss and gastric functions (stomach emptying effect) in people who are overweight or have obesity
adolescents and young adults who don’t achieve expected weight loss or who still have severe obesity after undergoing weight-loss surgery, also called metabolic and bariatric surgery
patients who have obesity andbinge eating disorder
women who are overweight or have obesity andpolycystic ovary syndrome

Find out if clinical studies are right for you.

Watch a video of NIDDK Director Dr. Griffin P. Rodgers explaining the importance of participating in clinical trials.

What clinical studies for prescription medications to treat overweight and obesity are looking for participants?

You can view a filtered list of clinical studies on prescription medications to treat overweight and obesity that are federally funded, open, and recruiting at ClinicalTrials.gov. You can expand or narrow the list to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health does not review these studies and cannot ensure they are safe. Always talk with your health care provider before you participate in a clinical study.