GLP-1 patient education
GLP-1 Medications: How They Work, Side Effects & Safe Use
Plain-language guidance on Ozempic, Wegovy, Mounjaro, Zepbound, Rybelsus, Saxenda, and the investigational drug retatrutide, built on FDA product labels, peer-reviewed clinical trials, and current clinical guidelines.
Find your GLP-1 topic
Start with the question you are trying to answer, then use the page that matches the medical, access, or provider-verification issue.
- GLP-1 medications: compare FDA-approved products, active ingredients, and approved uses.
- Side effects: understand common symptoms, serious warning signs, and what to ask a clinician.
- Weight loss: see how GLP-1 and related medicines fit into obesity care without promising individual results.
- Cost and access: separate insurance, shortage, savings-program, and pharmacy-source questions.
- Retatrutide: follow what is known about Lilly's investigational triple agonist and why it is not a prescription option.
- Provider verification: check licensure, prescribing standards, pharmacy transparency, and follow-up support before paying or sharing health information.
How GLP-1 medications work
GLP-1, or glucagon-like peptide-1, is a hormone released by the gut after eating. It helps regulate insulin response, reduces liver glucose output, slows stomach emptying, and contributes to fullness signals in the brain.
GLP-1 receptor agonists are prescription drugs that bind the GLP-1 receptor and produce a stronger, longer-lasting version of that signal. Tirzepatide is a related medication that activates both GLP-1 and GIP receptors. Retatrutide is being studied as a triple agonist that activates GLP-1, GIP, and the glucagon receptor, but retatrutide remains investigational and is not FDA-approved.
What to know before talking to your clinician
A clinician visit is safer and more specific when the product, active ingredient, reason for considering treatment, medical history, medication list, pregnancy plans, and procedure plans are clear before the visit.
Bring questions about the exact product label, whether the use is FDA-approved or off-label, contraindications, warnings, side effects, monitoring, insurance coverage, shortage status, and who to call if severe symptoms occur.
Side effects to discuss early
Common GLP-1 side effects are usually gastrointestinal: nausea, vomiting, diarrhea, constipation, abdominal pain, indigestion, burping, reflux, decreased appetite, and sometimes fatigue or headache. Labels also describe product-specific warnings and precautions.
Prompt clinician guidance is important for severe or persistent abdominal pain, severe vomiting or diarrhea, signs of dehydration, possible gallbladder symptoms, signs of low blood sugar, new or worsening vision changes in diabetes, allergic reactions, or boxed-warning symptoms listed in the product label.
How to spot a legitimate GLP-1 provider
Online GLP-1 offers vary widely. Before paying, sharing health information, or accepting a prescription, verify that a licensed clinician can legally care for patients in the relevant state, reviews the medical history, and signs the prescription.
The pharmacy source should be transparent about whether it dispenses an FDA-approved manufacturer product or a compounded product, and follow-up should be handled by a clinician rather than only by an intake form or checkout flow.
Retatrutide and other investigational drugs
Retatrutide is investigational and is not FDA-approved as a prescription product in the United States. Sponsor-reported trial results, registry records, and estimated completion dates are not FDA approval, an approved indication, or an FDA-approved product label.
Compounded and gray-market products sold online as retatrutide are not FDA-approved and are not the same as an approved prescription product. GLP-1 Guide covers retatrutide as a research topic only, not as an access, prescribing, dosing, compounding, or provider-sourcing topic.
What GLP-1 Guide intentionally does not do
This site does not provide medical advice, diagnosis, treatment, prescriptions, medication sales, provider referrals, provider rankings, or lead capture. It is designed to help patients and people considering GLP-1 care prepare better questions for licensed clinicians and pharmacists.
Medical pages show named medical-review attribution, reviewed dates, source lists, and medical disclaimers after reviewer sign-off.
FDA-approved GLP-1 and related incretin medications in the United States
| Brand | Active ingredient | FDA-approved use summary | Product label |
|---|---|---|---|
| Ozempic | Semaglutide | Type 2 diabetes; cardiovascular risk reduction in adults with type 2 diabetes and established cardiovascular disease. | OZEMPIC labeling |
| Wegovy | Semaglutide | Chronic weight management in adults and certain adolescents who meet label-defined criteria. | WEGOVY prescribing information |
| Rybelsus | Semaglutide oral tablets | Type 2 diabetes. | RYBELSUS labeling |
| Mounjaro | Tirzepatide | Type 2 diabetes. | MOUNJARO prescribing information |
| Zepbound | Tirzepatide | Chronic weight management in adults who meet label-defined criteria; obstructive sleep apnea in adults with obesity. | ZEPBOUND prescribing information |
| Saxenda | Liraglutide | Chronic weight management in adults and certain adolescents who meet label-defined criteria. | DailyMed label search |
| Victoza | Liraglutide | Type 2 diabetes in adults and pediatric patients age 10 years and older. | DailyMed label search |
| Trulicity | Dulaglutide | Type 2 diabetes; cardiovascular risk reduction in adults with type 2 diabetes and cardiovascular disease or multiple cardiovascular risk factors. | DailyMed label search |
| Byetta / Bydureon BCise | Exenatide | Type 2 diabetes. | DailyMed label search |
Frequently asked GLP-1 questions
What is a GLP-1 medication?
GLP-1 medications are prescription drugs that mimic glucagon-like peptide-1, a gut hormone involved in blood sugar regulation and fullness signaling. Some are FDA-approved for type 2 diabetes, and some are FDA-approved for chronic weight management in people who meet label-defined criteria.
What is the difference between Ozempic and Wegovy?
Ozempic and Wegovy both contain semaglutide, but they are different FDA-approved products with different approved uses and product labels. Ozempic is approved for type 2 diabetes; Wegovy is approved for chronic weight management in people who meet label-defined criteria.
What is the difference between semaglutide and tirzepatide?
Semaglutide acts on the GLP-1 receptor. Tirzepatide acts on both GLP-1 and GIP receptors. They are different molecules with separate FDA-approved products, evidence bases, warnings, side-effect profiles, and labels.
How much weight can people lose on a GLP-1 medication?
Published trials report different average weight changes for different products and study populations over defined time periods with lifestyle support. Trial averages do not predict an individual result, and a clinician should interpret the evidence against a patient's history, goals, risk profile, and follow-up plan.
Are GLP-1 medications safe?
FDA-approved GLP-1 and related incretin medications have product labels that describe contraindications, warnings, common adverse reactions, serious risks, and patient-counseling information. Safety depends on the specific product, the person, other medications, and ongoing clinician follow-up.
Is compounded semaglutide or tirzepatide the same as the brand-name product?
No. Compounded GLP-1 products are not FDA-approved and are not evaluated by FDA for safety, effectiveness, or quality before marketing. FDA has warned about safety risks involving unapproved GLP-1 products used for weight loss.
Is retatrutide available by prescription?
No. Retatrutide is investigational and is not FDA-approved as a prescription product in the United States. It is not legally available as a prescription medication outside clinical trials.
Does GLP-1 Guide prescribe medication, refer providers, or sell anything?
No. GLP-1 Guide is an independent educational reference. It does not provide medical advice, diagnosis, prescriptions, provider referrals, medication sales, or health-information lead capture.
GLP-1 Medications: How They Work, Side Effects & Safe Use sources
- FDA concerns with unapproved GLP-1 drugs used for weight loss, U.S. Food and Drug Administration. Accessed 2026-05-27.
- WEGOVY prescribing information, DailyMed. Accessed 2026-05-27.
- OZEMPIC labeling, DailyMed. Accessed 2026-05-27.
- RYBELSUS labeling, DailyMed. Accessed 2026-05-27.
- MOUNJARO prescribing information, DailyMed. Accessed 2026-05-27.
- ZEPBOUND prescribing information, DailyMed. Accessed 2026-05-27.
- A Study of Retatrutide (LY3437943) in Participants With Obesity or Overweight, ClinicalTrials.gov. Accessed 2026-05-27.
- AGA clinical practice guideline on pharmacological interventions for adults with obesity, PubMed. Accessed 2026-05-27.
- Nutrition and physical activity: an Obesity Medicine Association clinical practice statement, PubMed Central. Accessed 2026-05-27.