GLP-1s (short for glucagon-like peptide-1 receptor agonists) have been in the spotlight lately as more people add them to their weight loss toolbelt — and for good reason. These drugs are very effective at treating obesity and overweight. GLP-1s actually began as a diabetes drug, though, and they’re still used to help people with type 2 diabetes manage their blood sugar. What are GLP-1 medications, how effective are they, and what are the side effects to look out for? We’ll answer all your GLP-1 questions ahead.
GLP-1 receptor agonists are a class of medication initially developed to help people with type 2 diabetes manage their blood sugar levels. Weight loss appeared as a surprising side effect, so the drugs are now also used to help people with excess weight or obesity lose weight. You can also stay on a GLP-1 for chronic weight management. This can help you avoid weight gain after a weight loss journey. GLP-1s are only available with a prescription. Most come as an injection you give yourself either once a week or once a day, but you can also get oral GLP-1s in tablet form. In most cases, GLP-1 drugs are prescribed alongside lifestyle changes —like a healthy diet and physical activity —to help people lose weight and manage their weight and blood sugar long-term.
GLP-1 drugs work by mimicking the GLP-1 hormone your intestines naturally secrete when you eat. When you take GLP-1 medications, they bind to GLP-1 receptors in the pancreas, triggering the release of insulin. This is why GLP-1 drugs are also known as GLP-1 agonists — they activate these GLP-1 receptors. When you eat carbohydrates, they’re digested into blood sugar (glucose), which circulates in your bloodstream. Insulin is needed to move this blood sugar into your tissues, where it can be used for energy. GLP-1s help get this process going without you having to eat carbs. They tell the pancreas to release more insulin, so your body is using more of the glucose already in your blood. Plus, GLP-1 agonists decrease the secretion of glucagon (which tells the liver to release stored glucose), further reducing blood sugar levels. These medications also slow down how quickly your stomach empties its contents. This helps minimize spikes in blood sugar and makes you feel fuller for longer. GLP-1s also act on parts of the brain that control appetite and cravings. So, beyond all these blood sugar-reducing properties, GLP-1 agonists can:
These appetite-changing effects can help you eat more nutritious foods and avoid overeating.
Besides blood sugar control and reduced body weight, GLP-1s have other health benefits. Some GLP-1s can help:
Btw, drugs like semaglutide and liraglutide are GLP-1s. Tirzepatide is a GLP-1 and a glucose-dependent insulinotropic polypeptide (GIP). It targets two hormone receptors instead of just one.
You might recognize many names of GLP-1 drugs. Some are approved by the Food and Drug Administration (FDA) for type 2 diabetes and sometimes prescribed off-label for weight loss. Others are FDA-approved for weight loss for people with obesity or overweight. Here’s a GLP-1 drug list with some of the most common medications.
There are also compounded GLP-1s. These drugs are available for people with unique needs, like needing a very low starting dose or a personalized maintenance dose. Compounded drugs aren’t evaluated or approved by the FDA for safety, effectiveness, or quality.
GLP-1s can help people with type 2 diabetes, obesity, and overweight.
If you have a type 2 diabetes diagnosis, you may be eligible for a GLP-1 medication, such as:
Your healthcare provider may recommend trying other diabetes drugs first, like metformin. They can also work with you to find the best GLP-1 for your unique needs and condition.
When it comes to weight loss, healthcare providers prescribe GLP-1s to people with obesity or overweight, who have a weight-related health condition like:
Your provider will look at your body mass index (BMI) to determine if you have obesity or overweight. BMI is an estimate of body fat and body composition based on your height and weight. Depending on your needs, a provider may prescribe an FDA-approved weight loss medication or prescribe another medication off-label for weight loss.
GLP-1s are effective for weight loss and weight management. In fact, clinical trials have shown that GLP-1 medications for weight loss are more effective than placebos or other diabetes medications used for weight loss. Weight loss results vary depending on which GLP-1 you take. But as an example, a 2021 study funded by Novo Nordisk —the manufacturer of Ozempic® and Wegovy®—found that people with excess weight or obesity lost almost 34 pounds over 68 weeks. They took 2.4-milligram (mg) weekly doses of semaglutide. A 2024 analysis — also funded by Novo Nordisk — looked at people with cardiovascular disease and overweight or obesity who took 2.4 mg of semaglutide. The results found that weight loss was sustained over four years, and there was a 20 percent reduction in cardiovascular events. Of course, not every medication works for everyone in the same way. For instance, GLP-1 agonists are consistently more effective for weight loss among people who don’t have diabetes than for people with diabetes. In a 2022 review of 14 studies, researchers found that GLP-1 agonists led to an average weight loss difference of:
Plus, some GLP-1s are more effective than others. Semaglutide may be more effective than liraglutide, for example. An Eli Lilly-sponsored study found people taking 15 mg of tirzepatide lost an average of about 21 percent of their starting body weight in 72 weeks. Since results may vary, it’s crucial to talk to your healthcare provider about the best GLP-1 for you. In any case, research shows time and time again that GLP-1 weight loss drugs can target appetite reduction, enhance fullness, and slow digestion — all of which can promote weight loss.
GLP-1s are effective at helping people with type 2 diabetes manage their blood sugar levels. One real-world study found that Ozempic® lowered HbA1c (glycated hemoglobin) —a measure of blood sugar levels — by an average of 1.4 percent over about eight months. An Eli Lilly-sponsored study found that tirzepatide (an Eli Lilly product) was more effective at reducing HbA1c than semaglutide in higher doses, and similar in lower doses.
Like any drug, GLP-1 agonists have potential side effects. The most common side effects of GLP-1s are gastrointestinal and include:
These side effects are usually mild and go away on their own as your body gets used to the drug. They can crop back up when you move to a higher dose before subsiding again. Some people report mild symptoms like:
You might have heard of “Ozempic® face.” This is when you lose fat and muscle from your face, which can happen with any type of rapid, significant weight loss, whether GLP-1s are involved or not.
There are potential long-term GLP-1 risks, like inflammation of the pancreas (pancreatitis), gallbladder problems, and kidney problems. These risks are rare, though. GLP-1 drugs also come with boxed warnings from the FDA stating that the active ingredients (semaglutide, tirzepatide, liraglutide, and dulaglutide)cause thyroid tumors in rodents. It’s not clear if this happens in humans — and there’s currently no evidence that it does. If you experience worrying GLP-1 agonist side effects, let your healthcare provider know. They can determine if you need a dose adjustment or an alternative medication.
GLP-1s are safe for most people, but you shouldn’t take them if you:
A healthcare professional can make sure GLP-1 drugs are right for you before prescribing one for weight loss or diabetes.
If you don’t respond well to GLP-1 drugs for weight loss or diabetes, there are alternatives to consider. For weight loss, your options include:
A healthcare provider can talk you through GLP-1 alternatives and recommend the best ones for you. Hers offers access to personalized oral weight loss medication kits that can help support you on your journey. Depending on your needs, your kit may include some combination of bupropion, metformin, topiramate, and naltrexone. Weight loss kits contain compounded medications and haven’t been approved by the FDA. The FDA doesn’t review compounded products for safety, effectiveness, or quality. For type 2 diabetes, your healthcare provider may recommend diabetes drugs like metformin, empagliflozin, or dapagliflozin.
GLP-1 medications aren’t for everyone, but when used as directed, they’re an effective tool for the treatment of obesity and type 2 diabetes. If you’re considering GLP-1 drugs for weight loss, keep these things in mind:
Ready for change? Start by taking our free weight loss assessment to find out whether GLP-1s could work for you.
How often to take a GLP-1 depends on which GLP-1 you’re taking. You take Rybelsus®, Saxenda®, and Victoza® daily. And you take Ozempic®, Wegovy®, Mounjaro®, Zepbound®, and Trulicity® weekly.
Not exactly. Ozempic® contains the active ingredient semaglutide, which is one type of GLP-1. GLP-1s are a class of medications that includes semaglutide, tirzepatide, dulaglutide, and liraglutide.
