The 2026 GLP-1 Pipeline: 14 Drugs, Four Receptors, and What Actually Beats Tirzepatide

For about a decade, this category was one molecule and one receptor: semaglutide, hitting GLP-1. By 2026, that split into four receptors — GLP-1, GIP, glucagon, and amylin — combined in eight different ways across fourteen drugs at various stages of approval. If you've only heard of Ozempic and Zepbound, you're looking at maybe a fraction of what's actually happening in this space. Here's the full map.

Three things to know before the details

1. The receptor map has genuinely split. This isn't marketing spin about "next-gen" drugs. Four distinct biological levers are now in play, and the next few years of this category are about which combinations of them work best.
2. Tirzepatide (Mounjaro/Zepbound) is still the efficacy benchmark, and nothing has clean-beaten it yet. CagriSema — Novo Nordisk's amylin + GLP-1 combination — missed non-inferiority against tirzepatide 15 mg in a head-to-head trial at 84 weeks. A handful of others cluster below or near it. The molecules most likely to eventually beat it are the triple agonists.
3. Three drugs changed the conversation in late 2025 / early 2026: orforglipron (the first oral small-molecule GLP-1 to post strong Phase 3 data, brand name Foundayo), CagriSema (FDA application filed, decision expected late 2026), and mazdutide (the first dual glucagon/GLP-1 drug approved anywhere in the world, via China).

The landscape at a glance

All of these percentages are corporate-reported topline figures from different doses, durations, and patient populations — never treat a single number as an apples-to-apples comparison without checking the fine print.

The four receptors, in plain terms

• GLP-1. The original lever. Slows digestion so food sits longer, dials down appetite signals in the brain, helps the pancreas release insulin appropriately. Every drug on this list touches this receptor except the amylin-only ones.
• GIP. Adds insulin synergy and improves how fat tissue handles lipids. Tirzepatide was the first drug to add this on top of GLP-1, and it added roughly six percentage points of weight loss over semaglutide alone.
• Glucagon. The interesting one. Normally glucagon raises blood sugar, which is why it was left alone for years. But activated gently alongside GLP-1 and GIP, it raises resting energy expenditure and pushes the liver to burn fat instead of storing it — a genuinely different mechanism than "eat less." This is the lever behind the biggest liver-fat reductions in the entire category.
• Amylin. A separate satiety pathway, naturally co-released with insulin. Drugs that hit only this receptor (no GLP-1 at all) are showing GLP-1-class weight loss with what looks like a meaningfully lighter GI side-effect burden.

The drugs, grouped by mechanism

The original single GLP-1 agonists. Liraglutide (Saxenda/Victoza) was the first GLP-1 drug approved for weight management, back in 2014 — nearly seven years before Wegovy — but once-daily dosing has cost it share against weekly options. Dulaglutide (Trulicity) proved once-weekly GLP-1 dosing worked and remains a strong glycemic and cardiovascular drug, but it was never approved for obesity and produces only modest weight loss (roughly 3–5 kg). Semaglutide (Ozempic/Wegovy/Rybelsus) is the drug that defined the modern era, at roughly 15% weight loss at 68 weeks — still the reference point every newer drug gets measured against.

The GLP-1 + GIP dual agonists. Tirzepatide (Mounjaro/Zepbound) remains the efficacy benchmark at roughly 21% weight loss, and nothing has cleanly beaten it head-to-head yet. VK2735 hits the same receptor pair and is running both an oral tablet and a weekly injection through Phase 3 simultaneously — if the pill reaches market first, it's the first oral dual agonist.

The GLP-1 + glucagon dual agonists. This trio — survodutide, mazdutide, and pemvidutide — trade some raw weight-loss percentage (below tirzepatide) for a much bigger effect on liver fat, since the glucagon arm drives fat oxidation directly in the liver. Survodutide's standout is a 63.1% liver-fat reduction alongside 34% visceral-fat reduction, earning it FDA Breakthrough Therapy designation for MASH (fatty liver disease with inflammation) rather than obesity alone. Mazdutide became the first drug in this class approved anywhere, via China's regulator in 2025-2026. Pemvidutide has posted the strongest early MASH-resolution data of the three — 59% at 24 weeks — while still delivering real weight loss (up to 15.6%).

The amylin-only drugs. CagriSema combines cagrilintide (a long-acting amylin analog) with semaglutide in one weekly shot and is furthest along commercially — an FDA decision is expected in late 2026. It beats semaglutide alone head-to-head, but missed non-inferiority against tirzepatide 15 mg, narrowing its position to "better than sema, not quite tirzepatide." Eloralintide and petrelintide carry no GLP-1 activity at all, and both are producing GLP-1-class weight loss (up to 20% for eloralintide) with a meaningfully lighter side-effect burden — suggesting amylin is a genuine parallel pathway to GLP-1, not a lesser one.

The oral pill. Orforglipron, branded Foundayo, is a small-molecule GLP-1 agonist — not a peptide — built to work without the food and water timing restrictions that limited oral semaglutide (Rybelsus). It outperformed oral semaglutide head-to-head on both blood sugar and weight. This is the first genuinely credible "GLP-1 in a pill" for the large population that won't inject.

The structural outlier. MariTide pairs a GLP-1 agonist with a GIP antagonist — the opposite direction tirzepatide runs GIP — in a peptide-antibody conjugate dosed once a month instead of weekly. That two opposite approaches to the same receptor both produce roughly 20% weight loss is one of the genuinely open questions in the field.

The triple agonist. Retatrutide hits GLP-1, GIP, and glucagon at once — the first molecule to do so — and currently holds the highest reported weight-loss numbers on this list (24.2% at 48 weeks in Phase 2; a 28.3% topline figure at 80 weeks in Phase 3), plus the largest liver-fat reduction in the class, up to 86%. It isn't FDA-approved yet.

The pattern: each added receptor adds a mechanism

Semaglutide (GLP-1 alone) gets you appetite suppression. Add GIP (tirzepatide) and you get insulin synergy on top — about six more points of weight loss. Add glucagon on top of that (retatrutide) and you get raised energy expenditure — several more points, plus the biggest liver-fat effects in the category. Drugs that add glucagon but skip GIP (survodutide, mazdutide, pemvidutide) land below tirzepatide on the scale but ahead of it on liver fat. Amylin looks like a genuinely separate fourth axis, not a smaller version of the same thing.

Side effects: the class baseline

Every drug here shares a core profile: nausea, vomiting, diarrhea, and constipation, worst during dose titration and easing over four to eight weeks. Discontinuation rates run roughly 5–10% in trials. All carry a class-wide warning tied to thyroid tumors seen in rodent studies — anyone with a personal or family history of medullary thyroid cancer or MEN-2 syndrome should avoid this class. Pancreatitis and gallbladder disease are monitored across every program but haven't shown up statistically elevated versus placebo in well-run trials.

Two variations worth knowing: glucagon-receptor drugs carry a closely-monitored (but not, so far, clinically borne-out) theoretical hyperglycemia concern, and amylin-only drugs show a noticeably lighter GI burden at comparable efficacy. Across the whole class, roughly a quarter of total weight lost can be lean muscle if you skip adequate protein and resistance training — true on the newest triple agonist exactly as much as the oldest single agonist.

Where the honest disagreements are

On compounded supply. One camp says stick to brand-name only, since you can't verify what's in an unregulated compounded vial. The other says a verified compounder with real third-party lab testing (a certificate of analysis) produces something clinically equivalent to brand name, and lumping "verified" and "unverified" compounding together is the actual mistake. Both are right about different categories — what matters is whether the specific product in front of you has real, current lab verification, not whether it's compounded at all.

On tirzepatide versus CagriSema. The head-to-head trial settled the raw efficacy question in tirzepatide's favor. Whether CagriSema still wins commercially depends on how much weight patients put on the once-weekly amylin format and its tolerability versus tirzepatide's bigger number on the scale — a real trade-off, not a settled argument.

On whether the glucagon-receptor liver effects are a genuine separate mechanism, or just "more weight loss, so more liver fat loss." The cross-trial evidence — survodutide and retatrutide both post liver-fat reductions well beyond what weight loss alone typically produces — leans toward a real, direct hepatic effect. But these are cross-trial comparisons with different designs and doses, so treat the size of the gap as suggestive, not proven.

Starting now versus waiting

Verified-compounded access to a molecule like retatrutide exists today, at lower monthly cost than brand-name options, provided the source has real third-party testing behind it. Waiting for Foundayo or CagriSema gets you an FDA-approved, potentially insurance-covered product, or a needle-free option — at the cost of another 12 to 24 months, and typically $1,000+ a month out of pocket even with insurance.

Neither answer is wrong. If you're solving a problem now, the molecule and the verified supply chain both already exist. If your blocker is specifically not wanting to inject, an oral option is coming — but it's still a wait.

Educational information only, not medical advice. Investigational compounds discussed here are not yet FDA-approved and are not being recommended for use; approved GLP-1 medicines require a prescription. Talk to a qualified provider before starting, stopping, or changing any medication or protocol.

Sources: Jastreboff et al., NEJM 2023 (retatrutide Phase 2, PMID 37366315); Jastreboff et al., NEJM 2022 (tirzepatide SURMOUNT-1, PMID 35658024); Wilding et al., NEJM 2021 (semaglutide STEP-1, PMID 33567185); Wharton et al., NEJM 2025 ATTAIN-1 (orforglipron obesity, PMID 40960239); Rosenstock et al., Lancet 2026 ACHIEVE-3 (orforglipron vs. oral semaglutide, PMID 41765029); Sanyal et al., Nature Medicine 2024 (retatrutide MASLD, PMID 38858523). Additional company-reported topline data (CagriSema REDEFINE program, mazdutide GLORY trials, survodutide SYNCHRONIZE-1, MariTide Phase 2, NEJM 2025, PMID 40549887) are corporate/press-release figures pending full peer-reviewed publication. See also: Retatrutide beyond weight loss and GLP-1 muscle loss — what's actually protectable.