GLP-1 medications: a complete guide for 2026

How GLP-1 medicines work

GLP-1 is a hormone the gut releases after eating. The medicines in this class activate the same receptor for far longer than the natural hormone: they prompt the pancreas to release insulin when blood sugar is high, reduce the glucagon that raises sugar, slow how quickly the stomach empties, and act on appetite centers in the brain. The result is lower blood sugar and, for most people, less hunger and gradual weight loss.

Tirzepatide also activates the receptor for a second gut hormone, GIP, which is thought to contribute to its larger average effect on weight. Orforglipron, sold as Foundayo, is a newer pill that acts on the GLP-1 receptor but is a small molecule rather than a peptide, so it does not need the strict fasting rules of oral semaglutide.

The medicines and their brands

Most of the confusion around these drugs comes from one molecule carrying two brand names, each approved for a different use. The pens are not interchangeable between brands because the dose steps differ, so switching needs a new prescription.

• Semaglutide: Ozempic, a weekly injection for type 2 diabetes; Wegovy, a weekly injection and, since December 2025, a daily tablet for weight management; Rybelsus, a daily tablet for type 2 diabetes.
• Tirzepatide: Mounjaro, a weekly injection for type 2 diabetes; Zepbound, a weekly injection for weight management and for obstructive sleep apnea in adults with obesity.
• Liraglutide: Victoza for type 2 diabetes and Saxenda for weight management, both daily injections, now also available as generics.
• Dulaglutide: Trulicity, a weekly injection for type 2 diabetes.
• Orforglipron: Foundayo, a daily pill for weight management approved in April 2026.

Who they are prescribed for

For type 2 diabetes, GLP-1 medicines lower blood sugar, and several also have approvals to lower the risk of heart attack and stroke or to slow kidney disease in people with diabetes; guidelines recommend a drug with proven heart or kidney benefit for people with those conditions, whatever their blood sugar.

For weight management, the FDA-approved products are for adults with obesity, or with overweight plus a weight-related condition such as high blood pressure, type 2 diabetes or high cholesterol, alongside diet and activity. Wegovy is also approved for adolescents with obesity, and to lower heart attack and stroke risk in adults with heart disease and overweight or obesity; Zepbound is also approved for moderate to severe obstructive sleep apnea in adults with obesity.

They are not suitable for everyone. People with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2 should not take them, and they are stopped before a planned pregnancy.

What results to expect

Weight loss is gradual and depends on reaching and staying on the maintenance dose. In the SURMOUNT-5 head-to-head trial, people with obesity lost more weight on average with tirzepatide than with semaglutide over 72 weeks, and both far exceeded placebo in their own trials. Averages hide a wide range: some people lose much more, and some much less.

The effect lasts only while the medicine is taken. In an extension of the STEP 1 trial, people who stopped semaglutide regained about two-thirds of the weight they had lost within a year, which is why these medicines are generally prescribed as long-term treatment.

Side effects and safety

Nausea, diarrhea, vomiting and constipation are the most common side effects, mostly in the weeks after starting or increasing a dose. Eating smaller meals, stopping when full and avoiding very fatty food help, and the dose can be held at a lower step for longer if needed.

Less common but important risks include pancreatitis, gallbladder problems, and dehydration that can strain the kidneys. Low blood sugar is a risk mainly when these medicines are combined with insulin or a sulfonylurea, whose doses are often reduced. Every product in the class carries a boxed warning about thyroid C-cell tumors seen in rodents. Tirzepatide can make birth control pills less reliable for a few weeks after starting and after each dose increase, so a backup method is advised during those weeks. Tell the team before any surgery or procedure with sedation, because slowed stomach emptying matters for anesthesia; follow their instructions on whether to pause a dose.

Compounded semaglutide and tirzepatide

While the branded drugs were in shortage, compounding pharmacies were allowed to make copies. The FDA declared the tirzepatide shortage resolved in December 2024 and the semaglutide shortage resolved in February 2025, and with that the allowance for routine copies ended. A compounding pharmacy can still prepare a version for an individual patient when the prescription documents a clinical reason the approved product will not do, but compounded products are not FDA-approved, which means the FDA does not review them for safety, effectiveness or quality before they are marketed, and the FDA has received reports of dosing errors with them.

How to pay for them in 2026

Semaglutide and tirzepatide have no generic in the US yet, so each brand comes from a single manufacturer, and the ways you can pay depend on your coverage. Ask for the price on each route open to you before you fill.

• Commercial insurance: coverage differs between plans and by diagnosis, and a plan may require prior authorization, so check your formulary. The manufacturers’ savings cards can lower the copay for eligible commercially insured patients, subject to each card’s terms.
• Paying yourself: Novo Nordisk sells Wegovy and Ozempic through NovoCare Pharmacy, and Eli Lilly sells Zepbound and Foundayo through LillyDirect, at prices that depend on the dose; the government’s TrumpRx website also lists offers for some of these drugs.
• Medicare: Part D covers these drugs for diabetes and for other approved medical uses; from July 2026 to the end of 2027, the Medicare GLP-1 bridge program lets eligible enrollees get certain obesity GLP-1 medicines for a flat monthly copay, and Medicare-negotiated prices for the semaglutide family take effect in January 2027.
• Medicaid: coverage for weight management varies by state.
• Generics: liraglutide, the older daily GLP-1, is available as a generic, so pharmacies can quote their own cash prices for it if your prescriber thinks it suits you.

Switching and stopping

People switch between GLP-1 medicines for side effects, coverage or response. Doses are not directly equivalent between molecules, so the prescriber chooses a starting dose on the new drug, often a step lower than the previous one, to limit nausea. Stopping is a decision to plan with the prescriber, with attention to diet, activity and the weight regain that usually follows; for people with diabetes, blood sugar treatment needs adjusting before stopping.