GLP-1 medications explained: what GLP-1 is, how the drugs work, which brands are FDA approved for weight vs diabetes, pills vs injections, side effects, cost and stopping.
Fact-checked against FDA labels and official sources; not yet reviewed by a licensed clinician. This page is education, not medical advice. Talk to your doctor before starting, stopping or changing any treatment.
Key takeaways
- GLP-1 is a gut hormone that regulates appetite and calorie intake; GLP-1 medicines activate its receptor for much longer than the natural hormone.[1]
- Wegovy, Zepbound, Foundayo and Saxenda are FDA approved for chronic weight management; Ozempic, Mounjaro and Rybelsus are approved for type 2 diabetes, not weight.[3]
- In STEP 1, semaglutide 2.4 mg led to an average 14.9% weight loss over 68 weeks versus 2.4% on placebo.[11]
- In SURMOUNT-1, tirzepatide led to 15.0% to 20.9% average weight loss over 72 weeks by dose versus 3.1% on placebo.[12]
- Nausea is the most common side effect: 44% on Wegovy injection versus 16% on placebo, mostly during dose increases.[1]
In short: GLP-1 is a hormone your gut releases after eating that helps control blood sugar and signals fullness to the brain. GLP-1 medicines copy that signal. As of October 6, 2026, those FDA approved for chronic weight management are Wegovy (semaglutide, injection and pill), Zepbound (tirzepatide, which also acts on the GIP receptor), Foundayo (orforglipron, a pill) and Saxenda (liraglutide). Others, including Ozempic, Mounjaro and Rybelsus, are approved for type 2 diabetes, not for weight.
This guide explains the class: how it works, which brands are approved for what, pills versus injections, side effects, cost and what happens when people stop. Each medicine has its own page with the label details. This is general information, not medical advice.
What GLP-1 is
GLP-1 stands for glucagon-like peptide-1. It is one of the “incretin” hormones the gut releases when food arrives. The FDA labels describe it as a natural regulator of appetite and calorie intake, with receptors in brain areas that control appetite. It also helps the pancreas release insulin and lowers glucagon when blood sugar is high.
How GLP-1 medicines work
GLP-1 receptor agonists are made to activate the same receptor for much longer. Semaglutide is a modified version of GLP-1 with 94% of the same sequence; according to its label, it binds to albumin in the blood and resists breakdown by the DPP-4 enzyme, so it lasts long enough for once-weekly dosing. Orforglipron is a small, non-peptide molecule taken as a daily pill. Tirzepatide activates both the GLP-1 receptor and the receptor for GIP, another gut hormone; the Zepbound label notes that nonclinical studies suggest the GIP action may add to the effect on food intake.
In practice, the labels describe three effects: people feel full sooner and eat less, the stomach empties more slowly, and blood sugar is lowered in a glucose-dependent way. The labels for Zepbound and Foundayo add that weight loss with these medicines involves more fat mass than lean mass.
Approved for weight, or for diabetes: the list
| Brand | Active ingredient | Form | FDA status (label checked 2026-10-06) |
|---|---|---|---|
| Wegovy | Semaglutide | Weekly injection | Approved for weight management (adults; teens 12+); also heart-risk reduction and MASH |
| Wegovy pill | Semaglutide | Daily tablet | Approved for weight management and heart-risk reduction (adults) |
| Zepbound | Tirzepatide | Weekly injection | Approved for weight management and obstructive sleep apnea with obesity (adults) |
| Foundayo | Orforglipron | Daily tablet | Approved for weight management (adults) |
| Saxenda | Liraglutide | Daily injection | Approved for weight management (adults; children 12+ over 60 kg with obesity) |
| Ozempic | Semaglutide | Weekly injection; daily tablets | Approved for type 2 diabetes (with heart and kidney outcomes); not for weight |
| Rybelsus | Semaglutide | Daily tablet | Approved for type 2 diabetes; not for weight |
| Mounjaro | Tirzepatide | Weekly injection | Approved for type 2 diabetes (adults and children 10+); not for weight |
| Victoza; Trulicity | Liraglutide; dulaglutide | Injection | Approved for type 2 diabetes; not for weight |
The labels say not to combine two GLP-1 receptor agonists. Ozempic and Wegovy contain the same molecule but are not interchangeable: doses, devices and approved uses differ. Our Wegovy vs Zepbound and semaglutide vs tirzepatide pages put the main options side by side.
Who they are labeled for
The weight-management labels cover adults with obesity, or adults with overweight and at least one weight-related condition, always together with a reduced-calorie diet and more physical activity; some cover teens. The NIH describes these medicines as generally considered for adults with a BMI of 30 or more, or 27 or more with a condition such as high blood pressure or type 2 diabetes. People with a personal or family history of medullary thyroid carcinoma or MEN 2 should not use the injectable GLP-1 medicines, according to the boxed warning. Whether a GLP-1 medicine fits a particular person is for that person and their clinician to decide.
How much weight people lose in trials
Results differ by medicine, dose and person. In STEP 1, adults on weekly semaglutide 2.4 mg lost 14.9% of their body weight on average over 68 weeks, versus 2.4% on placebo. In SURMOUNT-1, adults on weekly tirzepatide lost 15.0% to 20.9% by dose over 72 weeks, versus 3.1%. In ATTAIN-1, adults on the highest dose of orforglipron lost 11.2% over 72 weeks, versus 2.1%. In OASIS 4, the semaglutide pill led to 13.6% versus 2.2% at 64 weeks. These were separate trials; the only head-to-head obesity trial, SURMOUNT-5, is covered on our comparison pages.
Injection or pill
Weekly injections (Wegovy, Zepbound) use a pen or vial; Saxenda is a daily injection. The Wegovy pill is taken every morning on an empty stomach with up to 4 ounces of water, then waiting at least 30 minutes before eating, drinking or taking other oral medicines. Foundayo can be taken with or without food. Pills avoid needles but do not avoid the digestive side effects. The weight-loss injections hub and the oral GLP-1 guide go into the practical differences.
Side effects
Digestive effects are the most common: on Wegovy injection, nausea was reported by 44% versus 16% on placebo, mostly while the dose was being increased. Serious risks on the labels include pancreatitis, gallbladder disease, low blood sugar with insulin or sulfonylureas, kidney injury from dehydration and aspiration during anesthesia. In January 2026 the FDA concluded there is no increased risk of suicidal thoughts with GLP-1 receptor agonists and asked makers to remove that warning. Full details: GLP-1 side effects. Protecting muscle with protein and strength work is part of the plan; see muscle loss on GLP-1s and eating on a GLP-1.
Other medicines, pregnancy and surgery
Because GLP-1 medicines slow stomach emptying, the labels note they may change how other pills are absorbed, and prescribers may monitor medicines that need precise levels more closely. Combined with insulin or a sulfonylurea, they raise the risk of low blood sugar, so those doses may need adjusting. The Zepbound, Mounjaro and Foundayo labels advise people taking birth-control pills to switch to a non-oral method or add a barrier method for a period after starting and after each dose increase. The Wegovy and Zepbound labels say weight loss offers no benefit during pregnancy and that the medicine should be stopped when a pregnancy is recognized. Before any surgery or procedure with anesthesia or deep sedation, tell the team you take a GLP-1 medicine, because of the risk of inhaling stomach contents.
Cost
Checked on October 6, 2026 on the manufacturers’ sites: Wegovy pens were $349 a month self-pay through NovoCare Pharmacy and Wegovy pills $149 to $299; Zepbound KwikPens $299 to $449 and Foundayo $149 to $349 through Lilly, by strength. With commercial insurance that covers them, savings cards can lower the cost to $25. Medicare’s GLP-1 Bridge (July 2026 through 2027) covers Wegovy, Zepbound KwikPen and Foundayo for weight management with a $50 copay for people who meet its criteria. See Wegovy cost and the GLP-1 cost comparison.
Compounded and counterfeit GLP-1s
Compounded semaglutide and tirzepatide are not FDA approved, and the FDA does not review them for safety, effectiveness or quality. The shortages that allowed widespread compounding ended in December 2024 (tirzepatide) and February 2025 (semaglutide). The FDA has also warned about counterfeit Ozempic and illegal “research use” products. Read compounded GLP-1s before considering one.
Stopping
GLP-1 medicines are labeled for long-term use, and trials show weight tends to return after stopping. In STEP 4, people switched from semaglutide to placebo regained 6.9% of their weight over 48 weeks; in SURMOUNT-4, people switched from tirzepatide regained 14.0% over a year. Any change should be planned with the prescriber. Our guide to life after a GLP-1 and the keep it off hub cover what helps. For every other medicine class, return to the weight-loss medications hub.
Related guides
Compounded Semaglutide and Tirzepatide: what FDA says and the risksCompounded semaglutide and tirzepatide explained: not FDA approved, the dated shortage history, FDA safety reports, counterfeit…
GLP-1 Side Effects: common, serious and how they are managedGLP-1 side effects from the FDA labels: common digestive effects by brand, serious risks, the thyroid…
Stopping a GLP-1: regain, what trials show and keeping resultsWhat happens when you stop a GLP-1: STEP 1 extension, STEP 4, SURMOUNT-4 and BMJ meta-analysis…
Emerging Weight-Loss Medications: the pipeline, with honest status labelsEmerging weight-loss medications: a dated pipeline table of retatrutide, CagriSema, zenagamtide, MariTide, survodutide, eloralintide and more,…Tools for this topic
Latest research
How to Read a Weight-Loss Study Headline in 5 StepsFive questions to ask before believing a weight-loss headline: who was studied, how many, how long,…
What’s Coming in 2027: Weight-Loss Treatments Awaiting FDA DecisionsWeight-loss treatments awaiting FDA decisions in 2027: CagriSema, retatrutide, survodutide, MariTide and more, with filing dates,…
Fake and Counterfeit Weight-Loss Drugs: How to Spot ThemCounterfeit Ozempic has reached U.S. pharmacies three times. The FDA alerts, what online test buys found,…Questions to ask a professional
- Could a GLP-1 medicine be appropriate for me, and what would we expect it to do?
- Do I have any personal or family history, such as thyroid cancer, MEN 2 or pancreatitis, that matters?
- Would a weekly injection or a daily pill suit my routine and health better?
- How should my diabetes or other medicines change if I start one?
- What is our long-term plan, including nutrition, strength training and what happens if I stop?
Frequently asked questions
What does GLP-1 stand for?
Glucagon-like peptide-1, a hormone the gut releases after eating. It helps regulate appetite and blood sugar.
Which GLP-1 medicines are approved for weight loss?
As of 2026-10-06: Wegovy (semaglutide, injection and pill), Zepbound (tirzepatide), Foundayo (orforglipron) and Saxenda (liraglutide) are FDA approved for chronic weight management.
Is Zepbound a GLP-1?
Yes, and more: tirzepatide activates both the GLP-1 receptor and the GIP receptor, so it is called a dual GIP/GLP-1 receptor agonist.
Is there a GLP-1 pill for weight loss?
Yes. The Wegovy pill (oral semaglutide) and Foundayo (orforglipron) are daily pills approved for weight management in adults. The Wegovy pill has strict empty-stomach rules; Foundayo can be taken with or without food.
What happens when you stop a GLP-1?
In trials, weight tended to come back after stopping. Plan any change with the prescriber, and keep up eating, activity and strength habits.
References
- WEGOVY (semaglutide) injection and tablets: prescribing information. Novo Nordisk, via DailyMed, 2026. (accessed October 7, 2026) Drug label
- ZEPBOUND (tirzepatide) injection: prescribing information. Eli Lilly and Company, via DailyMed, 2026. (accessed October 7, 2026) Drug label
- FOUNDAYO (orforglipron) tablets: prescribing information. Eli Lilly and Company, via DailyMed, 2026. (accessed October 7, 2026) Drug label
- SAXENDA (liraglutide) injection: prescribing information. Novo Nordisk, via DailyMed, 2026. (accessed October 6, 2026) Drug label
- OZEMPIC (semaglutide) injection: prescribing information. Novo Nordisk, via DailyMed, 2026. (accessed October 7, 2026) Drug label
- RYBELSUS and OZEMPIC (semaglutide) tablets: prescribing information. Novo Nordisk, via DailyMed. (accessed October 6, 2026) Drug label
- MOUNJARO (tirzepatide) injection: prescribing information. Eli Lilly and Company, via DailyMed, 2026. (accessed October 7, 2026) Drug label
- VICTOZA (liraglutide) injection: prescribing information. Novo Nordisk, via DailyMed. (accessed October 6, 2026) Drug label
- TRULICITY (dulaglutide) injection: prescribing information. Eli Lilly and Company, via DailyMed. (accessed October 6, 2026) Drug label
- Prescription Medications to Treat Overweight & Obesity. National Institute of Diabetes and Digestive and Kidney Diseases (NIH). (accessed October 7, 2026) Government page
- Wilding JPH, Batterham RL, Calanna S, et al.. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine, 2021. doi:10.1056/NEJMoa2032183 · PMID 33567185 · NCT03548935 (accessed October 7, 2026) Randomized trial
- Jastreboff AM, Aronne LJ, Ahmad NN, et al.. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine, 2022. doi:10.1056/NEJMoa2206038 · PMID 35658024 · NCT04184622 (accessed October 7, 2026) Randomized trial
- Wharton S, Aronne LJ, Stefanski A, et al.. Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment (ATTAIN-1). New England Journal of Medicine, 2025. doi:10.1056/NEJMoa2511774 · PMID 40960239 · NCT05869903 (accessed October 6, 2026) Randomized trial
- Wharton S, Lingvay I, Bogdanski P, et al.. Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity (OASIS 4). New England Journal of Medicine, 2025. doi:10.1056/NEJMoa2500969 · PMID 40934115 · NCT05564117 (accessed October 6, 2026) Randomized trial
- Rubino D, Abrahamsson N, Davies M, et al.. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance (STEP 4). JAMA, 2021. doi:10.1001/jama.2021.3224 · PMID 33755728 · NCT03548987 (accessed October 7, 2026) Randomized trial
- Aronne LJ, Sattar N, Horn DB, et al.. Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial. JAMA, 2024. doi:10.1001/jama.2023.24945 · PMID 38078870 · NCT04660643 (accessed October 7, 2026) Randomized trial
- FDA requests removal of suicidal behavior and ideation warning from GLP-1 receptor agonist medications. U.S. Food and Drug Administration, 2026. (accessed October 6, 2026) Government page
- FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize (content current as of 2026-04-01). U.S. Food and Drug Administration. (accessed October 6, 2026) Government page
- FDA’s concerns with unapproved GLP-1 drugs used for weight loss. U.S. Food and Drug Administration, 2026. (accessed October 7, 2026) Government page
- Wegovy at NovoCare Pharmacy: self-pay prices. Novo Nordisk (NovoCare Pharmacy). (accessed October 7, 2026) Other
- Zepbound coverage and savings. Eli Lilly and Company. (accessed October 6, 2026) Other
- Foundayo coverage and savings. Eli Lilly and Company. (accessed October 6, 2026) Other
- Medicare GLP-1 Bridge: information for providers. Centers for Medicare and Medicaid Services. (accessed October 7, 2026) Government page
Facts checked on October 6, 2026
Educational information, not medical advice. Talk with a qualified healthcare professional about your own situation. In an emergency call 911.