GLP-1 Drugs for Weight Loss: Everything You Need to Know

GLP-1 agonists (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, as these drugs are very effective.

The success of GLP-1 drugs for weight loss isn’t just anecdotal. Clinical studies continue to show they can help patients lose weight and maintain a healthy body weight.

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 drugs were initially developed to help people with type 2 diabetes manage their blood sugar. Weight loss was a surprising side effect, so they’re now also used to help those with excess weight or obesity lose weight.

GLP-1s are only available on prescription. Most come as an injection you give yourself either once a day or once a week, 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 patients lose weight and manage their weight long-term.

GLP-1 drugs mimic the GLP-1 hormone your intestines naturally secrete when you eat. When you take GLP-1 medications, they bind to GLP-1 receptors in your 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, you digest carbs into glucose (blood sugar), which circulates in your bloodstream. Insulin is needed to move this blood glucose into your tissues, where it can be used for energy.

Basically, GLP-1s help get this process going without you eating carbs, so your body is using more of the glucose already in your blood.

GLP-1 agonists also decrease the production of glucagon (stored glucose), further reducing blood sugar levels.

Furthermore, these weight loss medications slow down how quickly your stomach empties its contents. This helps minimize spikes in blood sugar and slows nutrient absorption.

GLP-1s also act on parts of the brain that control appetite and cravings. So, in addition to all these blood sugar-reducing properties, GLP-1 agonists can:

• Increase satiety (make you feel fuller)

• Reduce appetite (make you less hungry)

• Curb food cravings

• Reduce food noise

As well as better blood sugar control and reduced body weight, GLP-1s have other health benefits. They can help:

• Lower blood pressure

• Improve blood lipid disorders

• Reduce fatty liver

Some GLP-1s also lower the risk of heart attack, stroke, and death for people who have heart disease and type 2 diabetes.

Some GLP-1s were approved for obesity 10 to 20 years ago, but many of us are just hearing about them now. And some are approved by the FDA (U.S. Food and Drug Administration) for weight loss, whereas others aren’t.

Here’s a GLP-1 drugs list with some of the most common medications.

GLP-1s approved for the treatment of type 2 diabetes are often prescribed off-label for weight loss. This means healthcare providers prescribe them for weight loss despite their lack of FDA approval to treat obesity.

Compounded GLP-1s

You can also get compounded GLP-1s. These drugs use the same active ingredients as their non-compounded counterparts, but they aren’t approved by the FDA.

They can be a more affordable and widely available option (because some brand-name GLP-1 drugs are experiencing shortages). But you need to make sure you’re getting them from a reputable company like Hers.

Check out our guide to compounded GLP-1s to learn more.

GLP-1 agonists 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.

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 (but not diabetes) lost almost 34 pounds over 68 weeks. They took 2.4-milligram weekly doses of semaglutide.

A 2024 analysis — also funded by Novo Nordisk — looked at people with cardiovascular disease and overweight or obesity (but not diabetes) who took semaglutide. It 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 patients with diabetes.

In a 2022 review of 14 studies, researchers found that GLP-1 agonists led to an average weight loss difference of:

• 4 to 6.2 percent in people with diabetes

• 6.1 to 17.4 percent in people without diabetes

Also, semaglutide may be more effective than liraglutide for weight loss. And tirzepatide may be more effective than semaglutide in some doses.

Because results may vary, it’s crucial to talk to your healthcare provider regarding the best GLP-1 for you.

Weight loss results aside, 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.

Good candidates for GLP-1s drugs for weight loss have a body mass index (BMI) of 30 or higher. BMI is an estimate of body fat and body composition based on your height and weight.

Alternatively, your provider might recommend GLP-1s if your BMI is at least 27 and you also have one or more weight-related health conditions like:

• Heart disease

• Sleep apnea

• High blood pressure (hypertension)

• Type 2 diabetes

• High cholesterol

Get more details about how to qualify for semaglutide as an example.

Like any drug, GLP-1 agonists have potential side effects.

The most common GLP-1 side effects are gastrointestinal, including:

• Nausea

• Vomiting

• Diarrhea

• Indigestion

• Abdominal pain

• Constipation

These side effects are usually mild and go away on their own as your body gets used to the drug. They can be more intense when you move to a higher dose and then will often subside.

Some people report mild symptoms like:

• Dizziness

• Headaches

• Reactions at the injection site

• Nasal inflammation

There are also some potential long-term GLP-1 risks like pancreatitis, gallbladder problems, and thyroid cancer. These risks are rare, though.

If you experience worrying GLP-1 agonist side effects, let your healthcare provider know. They can determine if you need a dosage adjustment or an alternative medication.

GLP-1s are safe for most people, but you shouldn’t take them if you:

• Are pregnant or breastfeeding

• Have a personal or family history of medullary thyroid carcinoma

• Have a history of multiple endocrine neoplasia syndrome type 2 (MEN2)

A healthcare professional can make sure GLP-1 drugs are right for you before prescribing one for weight loss.

If you don’t respond well to GLP-1 drugs for weight loss, there are alternatives to consider.

Your options include:

• Metformin. Metformin is another weight loss diabetes drug. It’s FDA-approved for diabetes but sometimes prescribed off-label for weight loss. The daily pill can reduce appetite, lower blood sugar levels, and support weight loss.

• Topiramate. Topiramate, sold under the brand name Topamax®, is an antiseizure medication. For weight loss, it works by suppressing appetite and potentially reducing body fat.

• Naltrexone-bupropion. This combination is sold under the brand name Contrave®. Together, the medications curb cravings and target patterns of binge eating by acting on the appetite and reward centers in the brain.

A healthcare provider can talk you through GLP-1 alternatives and recommend the best ones for you.

Hers offers custom oral weight loss kits with prescription medications. Depending on your needs, they can include a combination of metformin, topiramate, bupropion, and naltrexone, which will work together to help you reach your weight loss goals.

GLP-1 medications for weight loss aren’t for everyone, but when used as directed, they’re an effective tool for the treatment of obesity.

If you’re considering GLP-1 drugs for weight loss, keep these things in mind:

• They’re only one piece of the puzzle. GLP-1s should be combined with healthy lifestyle habits for long-term success. Prioritize nutrition, exercise, sleep, and positive social support in addition to your prescribed meds.

• They may cause side effects. Every drug has potential downsides, including GLP-1s. While the most common ones are related to digestion, everyone responds differently. Report any concerns to your primary care provider.

• There are alternatives. GLP-1s not a good fit for you? Other weight loss medications may be appropriate, like metformin, topiramate, or a combo of naltrexone and bupropion.

Ready to break the weight loss cycle? Start by taking our free weight loss assessment to find out whether GLP-1s could work for you.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.