What is a GLP-1 medication?

GLP-1 drugs like Ozempic, Wegovy, Mounjaro, and Zepbound have become household names. This article explains what they do, who they are approved for, and what to discuss with a clinician before pursuing one.

The same active ingredient can appear under different brand names depending on what it is approved to treat. Semaglutide

Ozempic is FDA-approved for the management of type 2 diabetes.

Wegovy is FDA-approved for chronic weight management.

Both contain semaglutide. The injectable form is the established standard. An oral form of semaglutide exists; confirm current availability and approval status with your clinician or pharmacist.

Tirzepatide

Mounjaro is FDA-approved for the management of type 2 diabetes.

Zepbound is FDA-approved for chronic weight management.

Both contain tirzepatide. Unlike semaglutide, tirzepatide works on two hormones: GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). It activates both pathways, which is a distinct pharmacological mechanism, though it does not make tirzepatide the right choice for every patient.

At a glance | Brand name | Active ingredient | Primary FDA approval | Delivery | |---|---|---|---| | Ozempic | Semaglutide | Type 2 diabetes | Injectable | | Wegovy | Semaglutide | Chronic weight management | Injectable (oral form: confirm with clinician) | | Mounjaro | Tirzepatide | Type 2 diabetes | Injectable | | Zepbound | Tirzepatide | Chronic weight management | Injectable | A brand name does not determine how a drug will be used for you. A clinician reviews your medical history and determines which drug, which indication, and which dose applies to your situation. This article does not rank or recommend one medication over another.

FDA approvals are specific to an indication, meaning the condition a drug is approved to treat. A drug approved for type 2 diabetes is not automatically approved for weight loss, even if the active ingredient is identical to one that is. This distinction has real consequences. Prescribing and dosing: the approved indication shapes how a clinician prescribes the drug and at what dose. Insurance coverage: insurers often tie coverage to the approved indication. A plan that covers Ozempic for diabetes may not cover Wegovy for weight management, even though both contain semaglutide. Using a diabetes-approved drug for weight loss is considered off-label use, which affects coverage eligibility. Cost: patients may encounter the same active ingredient under different brand names at different price points, with different coverage outcomes depending on their plan. Coverage varies widely by insurance plan, employer, and state. Verify directly with your insurer.

For weight management (Wegovy, Zepbound) FDA labeling requires a BMI of 30 or higher, or a BMI of 27 or higher with at least one weight-related health condition, such as high blood pressure, type 2 diabetes, or high cholesterol. For type 2 diabetes (Ozempic, Mounjaro) These medications are indicated for adults with type 2 diabetes. They are not indicated for type 1 diabetes. Age considerations Approvals and age eligibility vary by specific drug. Not all formulations are approved for adolescents. A clinician should confirm what applies to a given patient. Wegovy is approved for chronic weight management in patients aged 12 and older. The STEP TEENS trial provided the clinical basis for that approval, demonstrating a 16.1 percent reduction in body weight compared with 0.6 percent for placebo in adolescents. Saxenda (liraglutide), an older GLP-1 medication, is also approved for patients aged 12 and older. Zepbound is currently approved for adults aged 18 and older only. No GLP-1 medications are approved for children under 12. Clinical trials are underway in younger populations, including children as young as 6. SURPASS-PEDS, a Phase 3 trial published in the Lancet in 2025, evaluated tirzepatide in children and adolescents aged 10 to 17 with type 2 diabetes. Key safety questions under study in younger patients include effects on growth, pubertal development, and bone density. These are areas where the evidence is still developing, and prescribers will be watching the data closely. Who should not use GLP-1 medications Per FDA labeling, these medications are not appropriate for people with a personal or family history of medullary thyroid carcinoma, or with multiple endocrine neoplasia syndrome type 2 (MEN2). Other contraindications exist. A complete medical history review is required before starting any GLP-1 medication.

Callout: Meeting the BMI threshold is a starting point, not a guarantee of eligibility. A clinician reviews your full medical history before any prescription is appropriate.

Meeting a BMI threshold is a starting point for GLP-1 eligibility, but it is not the full assessment. Before writing a prescription, clinicians evaluate a range of medical, psychiatric, and practical factors that the FDA labeling criteria alone do not capture.

There are absolute contraindications established in the prescribing information. All GLP-1 receptor agonists carry a Black Box Warning for patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 (MEN2). A known serious hypersensitivity to the drug or any of its components is also an absolute contraindication.

Beyond those, several relative contraindications require careful clinical evaluation. A history of pancreatitis warrants caution and close monitoring. For semaglutide specifically, advanced diabetic retinopathy is a concern because rapid improvements in blood sugar control can temporarily worsen eye disease. Clinically meaningful gastroparesis may be aggravated by the slowed gastric emptying these drugs produce. Patients taking insulin or insulin secretagogues face an increased risk of hypoglycemia when adding a GLP-1 medication. Impaired renal function is another consideration, since the gastrointestinal side effects common with these drugs can cause dehydration, which places additional strain on the kidneys.

Clinicians also look at factors that go beyond the label entirely. A comprehensive family history focused on endocrine tumors informs the thyroid risk assessment. Psychiatric history matters: patients with a history of depression or suicidal ideation require careful monitoring, though a causal link with GLP-1 medications has not been established. Eating disorder screening is particularly important in weight management settings, where up to one-third of patients may have undiagnosed eating disorders that require a different treatment approach. Baseline renal function is typically assessed before starting treatment, with ongoing monitoring as needed.

These are conversations to have with your prescriber before starting treatment, not reasons to avoid it. A thorough pre-treatment evaluation is a sign that your clinician is being careful, which is what you want.

Prior authorization is a routine part of accessing GLP-1 medications. As of 2024, approximately 87 percent of GLP-1 prescriptions require prior authorization from the insurer before a pharmacy can fill them.

The process is not fast. Average processing times run roughly 15 business days, though this varies by insurer. Approval rates also vary widely, with some plans approving as few as 44 percent of requests and others exceeding 64 percent. The most common reason for denial is not meeting the insurer's specific coverage criteria, which may differ from FDA labeling.

Many insurance plans require step therapy, meaning documented failure on older, lower-cost medications before they will authorize a GLP-1. This can add weeks or months to the timeline. For patients and prescribers alike, it requires patience and paperwork.

A notable recent change: Medicare Part D began covering GLP-1 medications for weight management in January 2026, with a 50-dollar monthly copay cap. Prior authorization still applies under Medicare, but the coverage expansion represents a significant shift for patients aged 65 and older who previously had limited options.

When a prior authorization is denied, appeals succeed in roughly 40 to 60 percent of cases when proper documentation is submitted. This typically includes clinical notes, lab results, and evidence of previously attempted treatments. Your prescriber's office can often guide you through this process.

Patient out-of-pocket costs have been increasing across the board for this drug class, regardless of insurance status. Understanding the authorization process, including what documentation your insurer requires and how to appeal a denial, helps patients navigate a system that can feel opaque. None of this is a reason not to pursue treatment if it is clinically appropriate; it is a reason to go in with clear expectations.

These medications are not approved for cosmetic weight loss. They are intended for people who meet specific clinical criteria, not for anyone who wants to lose a small amount of weight for appearance reasons. They are not a universal fit. Individual medical history, other medications, and existing health conditions all affect whether a GLP-1 medication is appropriate for a given person. They are not interchangeable without clinical guidance. Switching between brands or indications requires a prescriber's involvement. These are not over-the-counter products. Compounded versions carry real risks. The FDA has warned that compounded semaglutide and tirzepatide products have not been reviewed for safety, effectiveness, or quality, and some products on the market have been fraudulent. Patients should be cautious about any GLP-1 product that does not come from a licensed pharmacy dispensing an FDA-approved drug.

GLP-1 medications are well-studied relative to many drug classes, but honest gaps remain. Long-term safety data is still accumulating. Most large clinical trials ran for one to two years. The effects and risks of these medications over many decades are not yet fully characterized. What happens after stopping is an active research area. The long-term trajectory for patients who discontinue these medications is being studied. Tirzepatide's long-term profile is newer. Because the dual-agonist mechanism is more recent, its long-term safety record is less established than that of older GLP-1 drugs. Some populations were underrepresented in trials. Research is ongoing to better understand how these medications perform across diverse groups. These gaps are worth knowing about and worth raising with your care team.

The following questions are worth raising with a qualified clinician:

Do I meet the FDA criteria for any GLP-1 medication?

Which drug and which indication would apply to my situation?

What are the most common side effects, and how are they managed?

Are there medications I currently take that could interact with a GLP-1 drug?

What does my insurance cover, and what are my out-of-pocket options?

What happens if I need to stop the medication?

How will we measure whether it's working?

Depending on your situation, the right clinician might be your primary care physician, an endocrinologist, or an obesity medicine specialist. Telehealth prescribers are active in this space. If you pursue that route, verify the prescriber's credentials and confirm they have access to your full medical history before any prescription is written.

GLP-1 medications mimic a natural hormone to help manage blood sugar and appetite. The brand names can be confusing, but the underlying mechanism is consistent across the class. Eligibility is defined by FDA labeling and individual medical history, not by interest alone. If you are wondering whether one of these medications might be right for you, a clinician is the right starting point.