Obesity can affect your health and quality of life in so many ways. Carrying extra weight increases your risk for type 2 diabetes, heart disease, and some cancers. It also can cause depression, anxiety, and low self-esteem.
Losing just 5% to 10% of your body weight can help prevent many of these problems, but weight loss isn't easy. If you've struggled to get down to a healthy weight, medications called GLP-1 receptor agonists might help.
You may have already tried other weight loss medicines. These include:
- Bupropion-naltrexone (Contrave)
- Orlistat (Alli, Xenical)
- Phentermine-topiramate (Qsymia)
It can be frustrating when you're trying to lose weight but don't see any progress. If you haven't lost at least 5% of your body weight after taking one of these medicines for three to six months, your doctor might switch you to a different drug.
GLP-1 agonists, which come as an injection, can be effective treatments for obesity. They might help you lose 10% or more of your starting weight.
Which Therapies Specifically Treat Obesity?
A few categories of medicine work in different ways to promote weight loss. Some of them also treat type 2 diabetes.
Understanding how each medicine works, how you take them, and what side effects they might cause can help you make an informed discussion with your doctor. The weight loss medicine your doctor recommends will depend on your health, how much weight you need to lose, and how well other treatments have worked for you.
What Are GLP-1 Agonists?
GLP-1 is short for glucagon-like peptide-1. It's a hormone your intestines release after you eat.
GLP-1 triggers your pancreas to release insulin, which moves glucose from your blood into your cells for storage. That lowers your blood sugar. GLP-1 also stops the release of glucagon, another hormone your pancreas makes that raises your blood sugar. And GLP-1 slows the movement of food from your stomach to your intestines, which helps keep you feeling full longer.
GLP-1 agonists work like the GLP-1 your body makes. They lower blood sugar, which makes them helpful for treating type 2 diabetes. These medicines also reduce appetite to treat obesity. Your doctor might call GLP-1 agonists by one of their other names:
- GLP-1 receptor agonists
- Incretin mimetics
How Effective Are GLP-1 Receptor Agonists for Weight Loss?
Here are results from clinical trials for GLP-1 agonists:
The GLP-1 agonists that treat obesity come as an injection, which you can give yourself at home. You inject the liquid medicine under the skin of your thigh, belly, or upper arm with a needle and syringe or a prefilled pen.
How often you take the GLP-1 agonists depends on the medicine. Wegovy and Zepbound come in a once-weekly dose. Saxenda is a once-daily dose.
Semaglutide also comes in a pill called Rybelsus that you take once a day. It's only approved to treat type 2 diabetes, but some doctors prescribe Rybelsus off-label for obesity.
Weight loss medicines like the GLP-1 agonists don’t replace a healthy diet and exercise. They work best when you use them along with these lifestyle changes.
Are GLP-1 Agonists Safe?
GLP-1 agonists are generally safe, but they do have some risks. In some people they cause side effects or an allergic reaction. They might lower blood sugar too much, called hypoglycemia.
Studies have linked these medicines to rare but severe side effects like:
Because GLP-1 receptor agonists can inflame the pancreas, your doctor will likely not recommend one of these medications to you if you’ve had pancreatitis. If you or someone in your family has had medullary thyroid cancer or multiple endocrine neoplasia, you should not take these drugs. Some studies have linked them to thyroid tumors in rats. We need more in-depth research to know for sure if these medications pose a risk to humans.
GLP-1 agonists aren't safe to take during pregnancy because they might increase the risk for birth defects. It's important to discuss all the risks and benefits of these medicines with your doctor before you take them.
What Are the Common Side Effects of GLP-1 Agonists?
Like all medications, GLP-1 agonists may cause certain side effects.
How Much Do GLP-1 Agonists Cost?
The cost can vary slightly depending on which drug you take. In general, GLP-1 agonists may cost more than $1,000 without insurance coverage, rebates, or coupons. Insurance may not cover the cost unless you have type 2 diabetes, and some employer health plans don’t include these drugs.
Many drug companies that make GLP-1 medications offer patient assistance programs (PAPs) to help reduce out-of-pocket costs. They may give you the medication at a reduced cost or, sometimes, for free. You may need to meet certain income standards to qualify.
You may also be able to get a copay card that can reduce your out-of-pocket costs. Some drug companies will also help answer questions you have about your insurance coverage or other ways to get financial help.
You can find information about financial assistance for GLP-1 receptor agonists at:
Clinical Trials of GLP-1 Receptor Agonists
Research is still in progress to study the safety and effectiveness of both GLP-1 receptor agonists that have been approved already as well as new drugs in this class.
Clinical trials may compare different GLP-1 receptor agonists to each other. Other studies compare them to other classes of drugs to see which work better and why.
To find studies across the country, visit ClinicalTrials.gov to see:
- Information about the trial and its research goal
- Whether the study is still enrolling
- Where it's located
- What conditions you must meet to qualify
If you're interested in taking part in a clinical trial, ask your doctor to recommend one that's a good fit for you.
5 Things to Consider When Choosing a Treatment
When deciding on a medicine, have a discussion with your doctor about your health and weight loss goals. Each group of medicines comes with its own set of benefits and risks. Talk to your doctor about these five factors. Work together to come up with a weight loss plan that is safe, effective, and affordable for you.
Target weight. Some medicines can help you lose more weight than others. GLP-1 agonists are the most effective weight loss drugs. About 1 in 3 people who take them lose about 10% of their body weight. Some people lose up to 20% of their starting weight.
Health conditions. Weight loss medicines can be risky for people with certain medical conditions. You shouldn’t take GLP-1 agonists if you or a family member has had medullary thyroid cancer or multiple endocrine neoplasia syndrome. The reason is these medicines might increase the risk for thyroid cancer. Also avoid GLP-1 agonists if you've had an allergic reaction to them or to any of their ingredients.
Delivery method and dosing frequency. These medicines come as injections that you give yourself. Wegovy and Zepbound come as a once-weekly injection. You take Saxenda every day.
Side effects. It's common for GLP-1 agonists to cause GI side effects like nausea, diarrhea, and vomiting. The other side effects are different for each drug. Rarely, people have more serious problems from weight loss medicines. You'll want to look at both the common mild side effects and rare serious side effects for each drug so you know what to expect.
Cost. Some GLP-1 agonists cost more than $1,000 for a one-month supply. Insurance companies may not cover the cost of these medicines unless you have obesity plus a health condition like type 2 diabetes or high blood pressure. Contact your insurance company to find out what it will cover. If your insurance won’t pay for the drug, your doctor may be able to submit an appeal explaining why it's medically necessary.