GLP-1: What It Is, How It Works, and Every FDA-Approved Medication (2026)

A plain-language guide to the medicines behind Wegovy, Zepbound, Ozempic, Mounjaro and Foundayo: what they do, who they are for, what they cost, and how to start.

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At a glance

What it is
A hormone your gut releases after eating. It signals fullness and helps control blood sugar. GLP-1 medications copy it.
How it is taken
A weekly shot or a daily pill, depending on the medication.
Approved for weight loss
Wegovy, Zepbound, Foundayo and Saxenda. Ozempic and Mounjaro carry type 2 diabetes approvals.
Who it is for
Adults with obesity (generally a BMI of 30+) or overweight (BMI 27+) plus a weight-related condition. Wegovy and Saxenda are also approved for some teens aged 12+.
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Beginner’s guide

New to GLP-1? Start here

Seven steps, in the order most people take them. Each step links to our full, cited guide on that topic.

  1. Step 1: Is a GLP-1 right for me?

    The weight-loss medicines are approved for adults with obesity (generally a BMI of 30 or more) or overweight (27 or more) plus a weight-related condition such as high blood pressure or type 2 diabetes. A few medical histories rule them out.

  2. Step 2: Which medication?

    Most people choose between semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro), as a weekly shot or a daily pill, and between FDA-approved brands and compounded versions.

  3. Step 3: What will it cost?

    Your price depends on your insurance, the drug, and where you buy it. Manufacturer self-pay programs, coupons, and compounded options can cut the cost a lot.

  4. Step 4: How do I get a prescription?

    You need a licensed clinician, either your own doctor or a telehealth provider that reviews your history online. Check that the pharmacy behind any program is licensed.

  5. Step 5: Starting treatment

    Every GLP-1 starts at a low dose and steps up slowly, so your body can adjust. The first weeks are about learning the routine and handling early side effects.

  6. Step 6: Side effects, food, and results

    Nausea and other stomach side effects are the most common, and they usually ease as your dose settles. Eating enough protein matters, and results build over months, not weeks.

  7. Step 7: The long term, and stopping

    These are long-term medications for most people. Weight often comes back after stopping, so plan any change with your clinician.

Ready to compare options?

Independent scores for every provider, from the same evidence.

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The basics

What is GLP-1?

GLP-1 (glucagon-like peptide-1) is a hormone your gut releases after you eat. It does four things that matter for weight and blood sugar:

  • Releases insulin, only when needed

    It helps the pancreas release insulin when blood sugar is high, which is why it rarely causes low blood sugar on its own.

  • Turns down glucagon

    It lowers glucagon, the hormone that tells your liver to release stored sugar.

  • Slows your stomach

    Food leaves your stomach more slowly, so you feel full sooner and for longer.

  • Quiets hunger in the brain

    It acts on appetite centers in the brain, reducing hunger and the pull of food.

The science in detail

GLP-1 is a 30-amino-acid incretin hormone secreted by enteroendocrine L-cells in the distal small intestine and colon in response to food intake. The proglucagon gene encodes both glucagon (in pancreatic alpha cells) and GLP-1 (in intestinal L-cells), two biologically opposite signals built from related peptide structures.

Glucose-dependent insulin secretion: GLP-1 binds its receptor on pancreatic beta cells and amplifies insulin release only when blood glucose is elevated, the property that limits hypoglycemia compared with older diabetes drugs. Glucagon suppression lowers hepatic glucose output. Delayed gastric emptying blunts post-meal glucose spikes and prolongs satiety. Central appetite suppression acts mainly in the hypothalamus and brainstem, reducing hunger and food-reward signaling.

Native GLP-1 has a half-life of about 1–2 minutes because the enzyme dipeptidyl peptidase-4 (DPP-4) breaks it down. Pharmaceutical GLP-1s are engineered to resist DPP-4, stretching the half-life to hours (liraglutide, twice-daily exenatide) or days (semaglutide, tirzepatide, dulaglutide).

The medications

How GLP-1 medications work

GLP-1 medications copy the natural hormone but last far longer in the body (hours to days instead of minutes), so one weekly shot or daily pill keeps working. They come in a few types:

  • GLP-1 only

    GLP-1 receptor agonists

    Activate the GLP-1 receptor, just like the natural hormone. The longest-established group.

    Examples: semaglutide (Wegovy, Ozempic, Rybelsus), liraglutide (Saxenda, Victoza), dulaglutide (Trulicity)

  • Dual action

    GIP + GLP-1 agonist

    Tirzepatide activates two gut-hormone receptors at once, GIP and GLP-1. In published head-to-head trials it produced greater weight and A1C reductions than semaglutide.

    Examples: tirzepatide (Zepbound, Mounjaro) Learn more →

  • Pill, no fasting rules

    Small-molecule GLP-1 pill

    Orforglipron is not a peptide, so unlike Rybelsus it does not need to be taken on an empty stomach with only a small sip of water.

    Examples: orforglipron (Foundayo)

  • In trials, not approved

    Triple agonists and what comes next

    Retatrutide adds a third receptor, glucagon, on top of GLP-1 and GIP. It is investigational and not FDA-approved.

    Examples: retatrutide (Eli Lilly) Learn more →

Diabetes vs weight loss: what these medicines treat

Type 2 diabetes. More insulin, less glucagon and slower stomach emptying together lower fasting and post-meal blood sugar, producing A1C reductions of 1.0–2.5 percentage points across the class. This was the original FDA-approved use for the whole class, starting with Byetta in 2005.

Chronic weight management. Slower stomach emptying plus appetite suppression in the brain produce sustained reductions in food intake and meaningful weight loss. The weight indication arrived with Saxenda (liraglutide 3 mg) in 2014, then Wegovy (semaglutide 2.4 mg) in 2021, Zepbound (tirzepatide) in 2023 and Foundayo (orforglipron) in 2026.

All 11, side by side

Every FDA-approved GLP-1 medication, compared

Grouped by what each one is approved for. Tap a medication for its full guide or FDA label.

Approved for weight management(4)

Approved for type 2 diabetes(5)

Discontinued (historical)(2)

Generics and discontinuations: the details
  • Saxenda (Liraglutide 3 mg, Novo Nordisk): FDA-approved Dec 2014. First generic liraglutide for weight management launched by Teva on Aug 27, 2025. DailyMed label
  • Rybelsus (Semaglutide (oral), Novo Nordisk): FDA-approved Sep 2019. First oral GLP-1 RA. Cardiovascular risk-reduction indication added Oct 17, 2025 (7 mg + 14 mg only) per the SOUL trial. DailyMed label
  • Trulicity (Dulaglutide, Eli Lilly): FDA-approved Sep 2014. Long-acting GLP-1 RA. CV risk-reduction indication added (REWIND trial, Lancet 2019). Fc-fusion biologic — only the 351(k) biosimilar pathway applies; no biosimilar approved as of May 2026. DailyMed label
  • Victoza (Liraglutide 1.8 mg, Novo Nordisk): FDA-approved Jan 2010. Same molecule as Saxenda, lower-dose for diabetes. First generic GLP-1 RA in the US — generic liraglutide (Hikma) FDA-approved + launched Dec 2024. DailyMed label
  • Byetta (Exenatide (twice-daily), AstraZeneca): FDA-approved Apr 2005. First GLP-1 RA approved in the US. DISCONTINUED by AstraZeneca on Oct 25, 2024. Generic exenatide (Amneal) FDA-approved Nov 21, 2024 — historical reference. No boxed warning. DailyMed label
  • Bydureon BCise (Exenatide extended-release, AstraZeneca): FDA-approved Oct 2017 (BCise device). Extended-release exenatide microspheres. DISCONTINUED by AstraZeneca on Oct 28, 2024. No biosimilar approved (complex microsphere + autoinjector). DailyMed label

About this data: every medication here is FDA-approved with a published label on DailyMed (NIH) or Drugs@FDA. Indication, route and approval dates come from our primary-source-verified drug database; labels were pulled live from DailyMed with verbatim text extraction. Discontinuation dates are from a UnitedHealthcare provider notice citing AstraZeneca's October 2024 announcement.

Common confusion

Weight management vs type 2 diabetes — why brand names differ

The same active ingredient is sold under different brand names depending on what the FDA approved it for.

Semaglutide

  • Wegovy · weekly shot or daily pill
  • Ozempic · weekly shot
  • Rybelsus · daily pill

Tirzepatide

  • Zepbound · weekly shot; also sleep apnea with obesity
  • Mounjaro · weekly shot

Liraglutide

  • Saxenda · daily shot
  • Victoza · daily shot; generic available

Orforglipron

  • Foundayo · daily pill (approved April 2026)
Approved for weight management Approved for type 2 diabetes

Why it matters: insurance plans generally cover a brand only for its FDA-approved use. Prescribing Ozempic or Mounjaro for weight loss is legal but usually not covered. See our Cigna and Aetna prior-authorization guides for the exact policy wording.

What people pay

Cost and access

The list price is rarely what you pay. Manufacturer self-pay programs, savings cards and compounded options all change the number.

Semaglutide

Wegovy (brand) or compounded

List priceBefore any discount
$1,349/mo
NovoCare self-payStandard pen price; intro offers can be lower
$349/mo
Compounded, typicalMedian of 123 ongoing monthly prices we track
$179/mo

Tirzepatide

Zepbound (brand) or compounded

List priceSingle-dose pen, before any discount
$1,086/mo
LillyDirect self-payStarter dose; higher doses cost more
from $299/mo
Compounded, typicalMedian of 124 ongoing monthly prices we track
$249/mo

With commercial insurance that covers the drug, manufacturer savings cards can bring the copay down to as little as $25 a month. List and self-pay prices are from Novo Nordisk and Eli Lilly; compounded figures are live medians of ongoing monthly prices across the providers we track. Compounded drugs are not FDA-approved.

Live GLP-1 pricing index Cheapest without insurance Coupons & discounts Coverage by insurer

Not yet approved

What's next: the GLP-1 pipeline

These are in late-stage clinical trials and are not FDA-approved. Our pipeline tracker follows each trial and its results.

Common questions about GLP-1

The SURMOUNT-5 head-to-head NEJM 2025 trial (PMID 40353578) compared tirzepatide vs semaglutide directly: tirzepatide produced −20.2% mean body-weight loss at 72 weeks vs −13.7% for semaglutide. The FDA-approved chronic-weight-management options are Wegovy (semaglutide), Zepbound (tirzepatide), Foundayo (orforglipron), and Saxenda (liraglutide). Saxenda (liraglutide) is older and produces smaller weight loss (~5–8% at 56 weeks). Foundayo is too new for long-term comparative data. “Best” for an individual patient depends on tolerability, cost, indication overlap, oral vs injectable preference, and insurance coverage.
Both GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) are incretin hormones — meaning gut-secreted hormones that amplify insulin release in response to oral nutrient intake. GLP-1 is secreted by L-cells in the distal small intestine and colon; GIP is secreted by K-cells in the proximal small intestine. They have overlapping but distinct effects. Tirzepatide (Zepbound / Mounjaro) is a dual agonist that activates both receptors.
Yes and no. Both contain semaglutide as the active ingredient and both are made by Novo Nordisk. They differ in FDA-approved indication and dose: Ozempic is approved for type 2 diabetes (up to 2 mg weekly). Wegovy is approved for chronic weight management (up to 7.2 mg weekly). Insurance plans typically cover each only for its FDA-approved indication. Rybelsus is a third semaglutide brand — oral tablets — also approved for type 2 diabetes only.
Same active ingredient (tirzepatide) at the same weekly doses, made by the same manufacturer (Eli Lilly), but sold under different brand names by FDA indication: Mounjaro for type 2 diabetes (FDA-approved May 2022); Zepbound for chronic weight management plus obstructive sleep apnea in adults with obesity (FDA-approved November 2023, OSA December 2024). For the full side-by-side (cost paths, insurance coverage, quantity limits, off-label question) see our Mounjaro vs Zepbound complete comparison.
Yes — three FDA-approved GLP-1 options come as a once-daily pill as of 2026. Rybelsus is oral semaglutide (Novo Nordisk, FDA-approved 2019) for type 2 diabetes — a modified peptide tablet taken fasted with a small sip of water. Foundayo is oral orforglipron (Eli Lilly, FDA-approved April 2026) for chronic weight management — a small-molecule tablet without the fasting rules that apply to Rybelsus. And a once-daily Wegovy tablet (oral semaglutide), FDA-approved in December 2025, is approved for weight management. For the full side-by-side comparison of every oral GLP-1, see our GLP-1 pills 2026 comparison: Rybelsus, Foundayo & Wegovy oral. Patients considering a switch from Zepbound (subcutaneous tirzepatide) to oral Foundayo should know that the FDA labels do not contain a dose-equivalence conversion table and there is no published head-to-head trial — see our Foundayo ↔ Zepbound switch dose-equivalence guide for the verbatim §2 dose ranges side-by-side, the cross-trial efficacy comparison, and the practical re-titration logic.
Foundayo (orforglipron, Eli Lilly) was FDA-approved April 2026 — the newest FDA-approved GLP-1 medication and the first once-daily oral non-peptide GLP-1 receptor agonist for chronic weight management. Unlike Rybelsus (oral semaglutide), Foundayo does not require fasted administration with a small water volume. Beyond Foundayo, the active late-stage pipeline includes retatrutide (Lilly, GLP-1/GIP/glucagon triple agonist, phase 3 TRIUMPH trials), survodutide (Boehringer Ingelheim/Zealand, GLP-1/glucagon dual agonist), maridebart cafraglutide (Amgen MariTide, GLP-1/GIP), and ecnoglutide (Sciwind). None of those four pipeline candidates are FDA-approved as of May 2026. See our GLP-1 pipeline tracker for trial-by-trial status and our Foundayo FDA approval explainer for the full label, dosing, and access guide.
FDA-approved GLP-1 medications have a known and published safety profile based on phase 3 trials and post-marketing surveillance. The most common adverse reactions across the class are gastrointestinal (nausea, vomiting, diarrhea, constipation, abdominal pain) and tend to peak during dose escalation. Most GLP-1s carry a thyroid C-cell tumor boxed warning based on rodent studies; clinical relevance to humans is debated. Other documented safety concerns include gallbladder disease, pancreatitis, and (with rapid weight loss) potential for muscle-mass loss. Discuss personal contraindications and risk factors with your prescriber. See our research library for evidence-based deep-dives on gallbladder, thyroid, ileus / bowel obstruction, bone density and fracture risk, and mental health, anhedonia, and the FDA's January 2026 suicidality warning removal.
Yes — as of 2026 there are 3 FDA-approved generic GLP-1 receptor agonists in the United States: (1) Generic liraglutide (Hikma) — FDA-approved + launched December 2024, referencing Victoza for type 2 diabetes. The first generic GLP-1 RA approved in the US. (2) Generic exenatide (Amneal) — FDA-approved November 21, 2024, referencing Byetta (twice-daily) for type 2 diabetes. The brand Byetta itself was discontinued by AstraZeneca on October 25, 2024. (3) Generic liraglutide (Teva) — launched August 27, 2025, referencing Saxenda for chronic weight management. The first generic GLP-1 RA approved for weight loss in the US. There is NO FDA-approved generic for semaglutide (Wegovy/Ozempic/Rybelsus), tirzepatide (Zepbound/Mounjaro), dulaglutide (Trulicity, which is a biologic on a BLA — only the 351(k) biosimilar pathway applies), or orforglipron (Foundayo). Compounded semaglutide and tirzepatide are NOT generics — they are 503A-pharmacy-prepared products under the separate FDA compounding regulatory framework, and the FDA's enforcement-discretion windows for compounding semaglutide closed in 2025 after the FDA declared the shortage over on February 21, 2025.

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