All About GLP-1s

GLP-1 medications have become some of the most talked-about drugs in diabetes and weight management, and for good reason. They work in several ways at once, they’re backed by decades of research. And for people with diabetes, they’re opening new doors that weren’t available even a few years ago. Here’s everything you need to know.

What is a GLP-1?

To understand how GLP-1 medications work, it helps to first understand how the naturally occurring GLP-1 hormone works. GLP-1 is a hormone made in your small intestine that:

• Triggers insulin release from your pancreas, and as a result, lowers blood sugars.
• Blocks the body from making glucagon when it’s not needed, preventing more glucose from going into your bloodstream.
• Slows down how your stomach digests food so you feel full sooner.
• Tells your brain that you’re not hungry, so you eat less.

What is a GLP-1 medication?

GLP-1s are a class of medication. They work by mimicking and enhancing the effects of naturally occurring GLP-1 hormone. These medications attach to the same receptors in your body that your natural GLP-1 hormone uses, just with a stronger, longer-lasting result.

What’s the difference between a GLP-1 and a GLP-1/GIP dual agonist?

Some GLP-1 medications also target a second hormone called GIP (glucose-dependent insulinotropic polypeptide). GIP also triggers insulin release after eating, helps your body handle fat more efficiently, supports bone health and may protect nerve cells.

Medications that target both GLP-1 and GIP receptors (called dual agonists) tend to deliver stronger results for blood sugar control and weight loss. Mounjaro and Zepbound are the dual agonists currently on the market.

What GLP-1 medications are available?

There are injectable and oral options.

Injectable GLP-1s include once-daily Saxenda and Victoza, and once-weekly Ozempic, Trulicity, and Wegovy.

Oral GLP-1 options include Rybelsus and Wegovy, which must be taken first thing in the morning with no more than 4 oz of water—and you can’t eat or drink anything else for 30 minutes after. Foundayo is the newest oral option and the most flexible: it’s a once-daily pill you can take any time, with no food or liquid restrictions.

See our GLP-1 comparison chart for FDA-approved GLP-1 medications currently on the market.

What conditions are GLP-1 medications FDA-approved to treat?

When the first GLP-1 was discovered in 1984, there was little interest. But researchers later focused on its use in type 2 diabetes. By 2005, Byetta (which is no longer available) became the first GLP-1 approved by the FDA for use in type 2 diabetes. 

Since then, other GLP-1s have become available with FDA uses for type 2 diabetes and many other conditions, including:

• Type 2 diabetes (T2D): Mounjaro, Ozempic, Trulicity, Victoza, and Rybelsus are all approved here. On average, people see A1C improvements of 0.7% to 2.1%.
• Weight loss: Saxenda, Wegovy, Zepbound, and Foundayo are approved for people with an elevated BMI. Average weight loss ranges from 5% to 22.5%.
• Cardiovascular disease (CVD): Ozempic, Trulicity, Victoza, Wegovy, and Rybelsus are approved to reduce the risk of major cardiovascular events, like heart attack and stroke, by roughly 12% to 20% in people with T2D and/or overweight or obesity.
• Obstructive sleep apnea (OSA): Zepbound is approved for moderate-to-severe sleep apnea in adults with obesity. Significant weight loss reduces the tissue that puts pressure on the airway, cutting down on breathing disruptions.
• Chronic kidney disease (CKD): Ozempic is approved for people with T2D who also have CKD, a condition where the kidneys lose their ability to filter waste properly.
• MASH (metabolic dysfunction-associated steatohepatitis): Wegovy is approved for this long-term liver disease, where fat buildup leads to inflammation and scarring. More than 1.8 million people in the U.S. are diagnosed with MASH each year.

All GLP-1 and GLP-1/GIP medications should be used as part of a healthy diet and regular exercise.

Are GLP-1 medications approved for type 1 diabetes?

Not yet, but the evidence is building. For people with T1D, GLP-1 and GLP-1/GIP medications may lower insulin needs, reduce inflammation and protect the heart and kidneys. A newly published consensus statement now recommends considering GLP-1/GIP therapy for:

• Adults with T1D who have overweight or obesity
• Adults with T1D who aren’t meeting blood sugar goals on insulin alone, even at a healthy weight
• Teens and young adults with T1D who have overweight or obesity and aren’t reaching their targets on insulin—or who are meeting targets but may still benefit

If you and your healthcare provider (HCP) decide to try a GLP-1, the consensus statement recommends starting at the lowest possible dose and increasing slowly—every few months or not at all. Once you hit your weight and blood sugar goals, the dose should be brought down to the lowest amount that still works. That number will look different for everyone.

Remember that using a GLP-1 when you live with T1D requires ongoing insulin use, careful monitoring and regular communication with your diabetes care team.

How do you get a GLP-1 prescription?

The process is relatively straightforward:

1. Talk through your options with your HCP.
2. Get a prescription for the GLP-1 (or GLP-1/GIP) that fits your needs.
3. Fill it at an approved pharmacy like CVS, Walgreens, or Amazon Pharmacy.

What if insurance won’t cover your GLP-1

If the pharmacy tells you that you aren’t covered, ask them to explain why. Some common reasons you may encounter include: 

• If you have a high deductible or high co-pay, manufacturer discount programs can help. Ask your pharmacist or check GoodRx for current options.
• If your plan only covers certain medications, ask your doctor to switch the prescription to one your plan will cover. For example, your insurance may cover Zepbound but not Ozempic. In this case, you’d need to go back to your HCP and ask them to swap out the medication for what’s covered
• If your diagnosis doesn’t meet the approved criteria for coverage, you may qualify for self-pay programs like LillyDirect or NovoCare. Talk to your HCP to learn about these options.

Expert tip: Not all GLP-1s are created equal. You’ve probably seen TV commercials for cheaper, compounded versions of GLP-1 medications that are available through third-party sellers. But they aren’t FDA-approved and come with real safety risks. Stick with FDA-approved options and patient assistance programs widely available. They’re worth the extra step.

Getting started with GLP-1s

If you and your HCP feel that a GLP-1 or GLP/GIP is right for you, it’s important that you get started on the right foot. Here are a few tips to get you started:

• Manage side effects
• Maintain healthy body mass
• Follow a healthy eating plan that prioritizes protein
• Stay physically active

How do you manage side effects when starting a GLP-1?

Nausea, vomiting, diarrhea and constipation are the most common side effects, especially when you’re starting out or increasing your dose. They’re usually not severe, but they can disrupt your day. A few strategies that can help include:

• Starting at the lowest dose and increasing slowly with your HCP’s guidance. If you start to see increased side effects, back off your dose. 
• Eating small, frequent meals. Avoid large portions and high fat foods.
• Staying hydrated throughout the day in between meals. Aim for 8 to 12 cups of water per day.

How do you protect muscle and bone mass while on a GLP-1?

GLP-1s lead to decreased calorie (energy) intake. That also means a reduced intake of important vitamins and minerals, which can result in muscle and bone loss. They also increase your risk of pancreatitis, so supporting your body with healthy foods and exercise is important in the long run.

• Prioritize protein. aim for 1.0g to 1.5g per pound of body weight each day. Starting meals with 20 to 30g of protein from fish, beans, chickpeas, or tofu, is a practical way to hit that target.
• Strength training. Try to get at least 30 minutes of resistance exercise (weights or bands) two to three times a week, in addition to daily movement like brisk walking.
• Balance your plate. Fill half of your plate with vegetables, whole grains and fruit. A daily multivitamin can fill in the gaps.

Working with a registered dietitian can make all of this a lot easier to put into practice.

The bottom line about GLP-1s and diabetes

The GLP-1 landscape is evolving fast, especially for the T1D community, where many people are already using these medications off-label while the evidence catches up.

Want to learn more about GLP-1s and diabetes? GLP-1s aren’t one-size-fits-all, and there’s a lot to learn as you go. Explore our GLP-1 Hub for more on how these medications work, what they treat, and how to navigate them with your care team.

This content was made possible by Lilly, an active partner of Beyond Type 1. Beyond Type 1 maintains editorial control over its content.