Learning About GLP-1 Medicines for Weight Loss

Glucagon-like peptide-1 (GLP-1) receptor agonists are medicines that can help people lose weight. They are also used to treat chronic conditions such as type 2 diabetes, kidney disease, and obstructive sleep apnea.

GLP-1 medicines are human-made versions of a hormone that is made in your small intestine. Most of the food you eat is digested and absorbed there. This hormone causes your pancreas to release insulin as your body needs it. This helps to lower and control your blood sugar levels, slow how quickly you digest your food, and promote that “full” feeling you get after you eat.

GLP-1 medicines work in the same way to help you lose unwanted pounds. When you take these medicines, you may eat fewer calories, and you may not feel hungry. You may not even have a desire to eat. And you may feel full longer after you eat because food stays in your stomach longer.

Losing weight while taking GLP-1 medicines can also help reduce the risk of obesity-related health conditions. Your doctor will check whether weight loss improves any health conditions you may have, such as type 2 diabetes, heart disease, high cholesterol, and high blood pressure.

GLP-1 medicines are used long-term along with healthy eating and being active.

GLP-1 medicines may be an option for people who have obesity or who are overweight and have weight-related conditions, such as high blood pressure or diabetes. While these medicines can be an effective tool to help people lose weight, they aren’t for everyone.

In general, GLP-1 medicines aren’t recommended if:

• You have a history of eating disorders, pancreatitis, or thyroid disease. This is due to an increased risk of serious problems from GLP-1 medicines.
• You are pregnant.
• You have a history of depression. Studies show a possible link between GLP-1 medicines and a rise in mood changes, worsened depression, and increased anxiety.

GLP-1 medicines aren’t recommended for children under age 12. But some of these medicines are approved for children ages 12 and up.

There are many types of GLP-1 medicines that are used for weight loss. Some are approved by the U.S. Food and Drug Administration (FDA) to treat both diabetes and obesity. Others are approved for treating only diabetes. But they also may be prescribed for weight loss.

Here are some examples of GLP-1 medicines used for weight loss. For each item in the list, the generic name is first, followed by examples of brand names.

• Liraglutide (Saxenda). It may help you feel less hungry or feel fuller sooner. It’s given as a shot once a day.
• Orforglipron (Foundayo). It may help slow digestion and help you feel less hungry or feel fuller sooner. It’s taken as a pill once a day.
• Semaglutide (Ozempic, Rybelsus, Wegovy). It may help regulate blood sugar and help you feel less hungry or feel fuller sooner. They may be given as a shot or pill.
• Tirzepatide (Mounjaro, Zepbound). This is what’s called a dual agonist because it has human-made versions of both GIP and GLP-1. GIP stands for glucose-dependent insulinotropic polypeptide. This is a natural hormone that your gut makes to stimulate insulin release after eating. It may help regulate blood sugar and help you feel less hungry or feel fuller sooner. This medicine is given as a shot once a week.

Many people who take GLP-1 medicines lose weight. A recent review of studies showed that more than 75% of those who took a GLP-1 medicine lost weight compared to those who took a “dummy” treatment (such as a sugar pill), called a placebo.

In the same review, semaglutide and tirzepatide were shown to be the two most effective GLP-1 medicines for weight loss. For example, people who take semaglutide are able to lose about 15% of their body weight after being on the medicine for about 1 year.

Studies also show that the types of GLP-1 given as a shot may be more effective than the types that you take as a pill. But the pill works almost as well as the ones that you inject. The pill may be a good option for people who don't want to give themselves a shot.

While GLP-1 medicines help many people lose weight, they don’t work for everyone. If you’re having a hard time reaching your weight goals, talk with your doctor about other things you can try.

The side effects from GLP-1 medicines may be mild and go away over time. When you take a GLP-1, you may:

• Have belly pain.
• Feel bloated.
• Be constipated.
• Have diarrhea.
• Feel sick to your stomach.
• Feel like your stomach isn’t emptying fast enough.
• Vomit.

You may also have other side effects. For example, you may:

• Feel very tired.
• Get headaches.
• Have indigestion.

If you’re having problems with side effects, talk to your doctor. You may be able to change the medicine dose or change the type you take.

Like with any medicine, taking a GLP-1 has some risks. In rare cases, they may include:

• Acute kidney injury.
• A change in how well other medicines may work, such as contraceptives and insulin. This is because your stomach is emptying at a slower rate while taking GLP-1 medicines.
• Gallstones.
• Bone density loss and not getting enough essential vitamins and minerals. This may be more of a problem in older adults.

Because of the popularity of these drugs, the FDA now issues warnings about being careful to take GLP-1 medicines only when a doctor prescribes them to you. Buying a GLP-1 medicine without a prescription could mean the medicine is of poor quality, is the wrong dose, or has different and even harmful ingredients. The FDA warns that taking an unapproved and unregulated GLP-1 medicine poses severe health risks and may lead to a hospital stay.

Always talk to your doctor first before taking a GLP-1 medicine. And take it exactly as prescribed.

Many people regain some or most of the weight they lost if they stop taking GLP-1 medicines. If you stop taking them, healthy eating and activity may help limit how much weight you gain back.

Keep in mind that GLP-1 medicines for weight loss are intended to be a long-term treatment, not a quick fix, to reduce the risks of being overweight and having related health conditions.