Guide to GLP-1 Medications: What Are They & How Do They Work?

Medically reviewed by: Kristin Baier, MD

At Calibrate, we know that metabolic health goes beyond what the scale says: It means you’re also healthy and balanced on the inside.

Reprogramming your metabolic system isn’t about restricting calories or implementing extreme physical activity into your routine. Instead, it’s about incorporating impactful and sustainable changes in the foods you eat, how you sleep, how much you exercise, and how your emotional health is supported. 

With Calibrate, you’ll also leverage the power of clinically proven, FDA-approved medications called GLP-1 receptor agonists.

Calibrate prescribes a select number of GLP-1 agonists that are either indicated specifically for weight loss or indicated for off-label use for weight loss. These medications include: 

• Semaglutide (Ozempic®, Wegovy®, Rybelsus®)
• Tirzepatide (Mounjaro®)
• Liraglutide (Saxenda®)
• Dulaglutide (Trulicity®)

These medications are thought to help lower your set point and send signals to your brain to regulate your metabolic function, reduce your appetite, and help you feel full.

Keep reading to learn more about GLP-1 meds and their unique benefits when it comes to improving metabolic health. We spoke with obesity medicine specialist and Calibrate Clinical Director Kristin Baier, MD, about what to know.

Ready to learn more about Calibrate’s Metabolic Reset? Find out if you're eligible: Take the quiz.

What are GLP-1 medications?

GLP-1s (glucagon-like peptide-1 receptor agonists), also known as incretin mimetics, are a class of prescription medications that have been proven to be effective in the treatment of type 2 diabetes and in support of weight loss.

GLP-1 medications mimic the effect of the GLP-1 hormone naturally produced in the gastrointestinal tract. GLP-1 meds were initially approved by the U.S. Food and Drug Administration (FDA) in 2005 as a treatment for type 2 diabetes. Experts soon learned that, in addition to improving blood glucose levels and A1C for diabetes care, GLP-1s also brought about significant weight loss and other metabolic health benefits. 

Most recently, a different type of GLP-1—tirzepatide, brand name Mounjaro®—was approved by the FDA in 2022. Mounjaro® works similarly to the other drugs in the GLP-1 family, but it stimulates two incretin hormone receptors. involved in blood sugar control: Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). This unique dual action makes it the first-in-class medicine that acts on both of these receptors.

How do GLP-1 medications work?

In your body, incretin hormones are released whenever food is consumed. Among other things, they help promote a feeling of fullness by delaying gastric emptying and activating the satiety centers in the Hypothalamus of the brain. They also boost insulin production in the pancreas and suppress glucagon production, both of which help normalize blood sugar levels.

All of this happens in a glucose-dependent manner, which means incretin hormones—or their imitators, i.e. GLP-1 and GIP receptor agonists—are unlikely to cause severe hypoglycemia unless combined with certain diabetic medications such as insulin or sulfonylureas..

What about your natural incretin hormones? Studies have found that people with overweight or obesity may have a reduction in incretin effects, particularly if they have had frequent weight fluctuations due to yo-yo dieting. GLP-1 medication narrows the gap, making it easier to reach your goals.

The GLP-1  medications used in the Calibrate program help your body to fight the natural increases in appetite and hunger hormones that occur as you begin to lose weight. All GLP-1 medications need to be used alongside lifestyle changes, i.e. changes to food, sleep, and exercise. These drugs tend to work best when accompanied by coaching and support from trained professionals. This helps you stay accountable to your new routine and makes lifestyle changes easier to incorporate into your busy schedule.

Why does Calibrate use GLP-1 medications? 

GLP-1 drugs target the underlying biology of weight loss by improving how your body handles insulin and glucose while also optimizing hormonal responses in the brain that regulate appetite.

GLP-1s ultimately work to improve metabolic health, with far-reaching benefits including reduced inflammation and cardiovascular (heart disease) risk. In this way, these medications don’t just help you lose weight—they potentially help you to live a longer and healthier life.

As mentioned earlier, the GLP-1 meds prescribed by Calibrate doctors include Wegovy®, Ozempic®, Mounjaro®, Rybelsus®, Trulicity®, and Saxenda®. Depending on your unique health history and profile, you may also be prescribed metformin for additional metabolic support, which can be safely used simultaneously with GLP-1 medications.

There are other GLP-1 receptor agonists on the market that Calibrate does not prescribe, including Victoza® (liraglutide), Adlyxin® (lixisenatide), Byetta® (exenatide), and Bydureon® (exenatide). This is primarily due to these medications’ lower effectiveness when compared to other, newer GLP-1s.

Why isn’t it medication alone in the Calibrate program?

Weight loss is a complex biologic process that requires a comprehensive approach for sustainable results. Calibrate is built on the principle that small steps lead to big wins. Medications are a temporary tool used by Calibrate to create favorable changes in conjunction with our 4 lifestyle pillars. Clinical studies have shown the combination of medication and ILI is necessary for optimal results.

The goal is that, by the time you stop taking GLP-1s, not only will you have lost weight and improved your metabolic system significantly—you will also have the tools to maintain the food, exercise, sleep, and emotional health habits needed to sustain those changes over time.

Will my insurance company cover the cost?

Many commercial insurance plans cover GLP-1s at $25 a month or less after you reach your deductible, but because all insurance plans are different and have different criteria for weight loss medication, we can’t say definitively whether GLP-1s would be covered by your specific plan before you join.

One of the major benefits of joining Calibrate is that our team will navigate insurance so you don’t have to. We’re dedicated to finding the best possible coverage for your GLP-1 medication. Our team uses proprietary tools and data to navigate medication coverage and availability. We support you by:

• Communicating with your insurance on your behalf 
• Exploring clinically appropriate GLP-1 to find you the most effective and low-cost option
• Applying relevant patient access programs to help you get affordable coverage, when possible

The result? More support finding the best medication for you. 

How do GLP-1 meds differ from other weight loss medications?

 GLP-1s are unlike other weight loss medications on the market as they also improve metabolic health which is the foundation of sustainable weight loss.

Phentermine, for example, is a stimulant (an amphetamine-like analog) that reduces hunger so that you can more easily stick to a low-calorie diet—but again, restricting food intake is not a sustainable solution for weight loss. Phentermine can also cause serious side effects including migraines, increased thirst, dry mouth, and significant elevation in blood pressure—which can force your heart to work harder and exacerbate any existing heart conditions. 

Contrave, another prescription weight loss medication, is a combination of Wellbutrin (a medicine primarily used in the treatment of depression), and naltrexone (a drug used primarily in the prevention of alcohol or opioid abuse). Like phentermine, Contrave helps to reduce appetite but does not address the metabolic health components like GLP-1s do.

Risks & side effects of GLP-1 medications

GLP-1 contraindications

There are several contraindications for GLP-1 medications to keep in mind. Specifically, GLP-1s should not be used by individuals with a history of pancreatitis or people who have gallbladder disease. In addition, GLP-1s are contraindicated if you have a personal or family history of medullary thyroid cancer or MEN (multiple endocrine neoplasia) type 2, or a personal history of pancreatic cancer

Since the first GLP-1 medication was approved in 2005, research demonstrates that, for most people, GLP-1 medications are a safe and effective treatment option to improve metabolic health and support weight loss, and the medication has even been approved for use in children twelve years of age and older.

Side effects of GLP-1 medication 

Many individuals don’t have any side effects at all with GLP-1s. Those that were reported were generally mild and severe adverse events were rare.

For individuals who do experience side effects, nausea is the most common. However, nausea usually subsides after 3-4 weeks as your body adapts to the medication (keep in mind that it can return with each increase in dose).

It is possible to stay on a lower dose for an extended time if needed to mitigate side effects. In studies, only a few patients stopped taking GLP-1s because of side effects, and those were mostly GI-related events. 

Other possible side effects of GLP-1 medications include:

• Nausea
• Diarrhea
• Vomiting
• Constipation
• Stomach (abdomen) pain
• Bloating, belching, or gas
• Heartburn
• Headache
• Dizziness
• Injection site reaction
• Hypoglycemia in patients with type 2 diabetes
• Gastroenteritis
• Fever
• Increased lipase and or amylase
• Increased heart rate (tachycardia)
• Alopecia (hair loss)
• Acute kidney injury
• Hypersensitivity reaction
• Chronic renal failure exacerbation
• Syncope
• Ileus
• Fatigue
• Retinal disorder (in patients with diabetes)
• Rash
• Hypotension (low blood pressure)
• Angioedema and/or anaphylaxis

Talk to your healthcare provider about any side effects of your GLP-1 medication that are bothersome or don’t go away. The Calibrate Medical Team can offer recommendations and supportive care for any issues that arise. If you experience any allergic reaction such as anaphylaxis or shortness of breath, you should seek immediate medical care at an emergency room.

Hypoglycemia is rare with GLP-1 medications. Talk to your healthcare provider to learn more.

Can I take GLP-1s with other medications?

GLP-1s are safe to take with most other medications. Your doctor will review your medical history and medication lists to avoid any contraindications. Keep in mind that GLP-1s are not typically prescribed for individuals with type-1 diabetes.

How long does it take for GLP-1 medication to work? 

GLP-1 medications aren’t short-term fixes. They form part of a comprehensive program designed to make long-lasting changes to your life and health. When you first start a GLP-1 medication, your doctor will explain what to expect and what dosage to begin with. You will then titrate your dose gradually up to a higher sustained dose as tolerated, depending on the specific medication and tolerability.

Your Calibrate medical team can provide more specific guidance about timing, but most GLP-1 medications begin to affect your blood glucose levels upon starting especially when combined with dietary changes.  Your medication plan is individualized to your specific medical history and progress, therefore, the amount of time on the medication will also differ from person to person. How long can I stay on GLP-1 medication?

GLP-1 medications are considered safe for long-term use—however, Calibrate doctors prescribe the GLP-1 medication as a temporary aid to improve metabolic health. Ultimately, the GLP-1 medication is just a tool to help achieve weight loss and better glucose control. Once this is achieved, the goal is to come off the medication while sustaining improvements through lifestyle interventions.  

What else should I know about GLP-1 medications?

If diet and exercise have not worked for you in the past, it’s because weight loss is not generally about your willpower—it is your biology. GLP-1s can favorably alter your hormones to optimize your chances of weight loss through improved metabolic health. If you’re interested in improving your metabolic health, take the quiz to find out if you’re eligible for the Calibrate Metabolic Reset. In addition to receiving access to the Calibrate Medical Team, as a member, you’ll also be paired with a 1:1 accountability coach who will support you in lifestyle changes to help you sustain your weight loss in the long run.

Joining Calibrate can help you achieve your weight loss goals while maintaining a healthy and well-balanced lifestyle. 

Ready to get started? Find out if you're eligible: Take the quiz.