Weight Loss & Metabolic
GLP-1 Alternatives: Next-Gen Weight-Loss Peptides Ranked by Evidence
Beyond Ozempic and Wegovy: a clinical-evidence ranking of the next-generation metabolic peptides — the dual and triple incretin agonists and amylin analogues — for weight loss in 2026.
GLP-1 alternativesweight-loss peptidestriple agonistamylin analoguehuman RCT evidence
The quick verdict
The next-generation metabolic peptides are the rare corner of peptide science with genuine human RCT evidence — here they are ranked by the strength, maturity, and magnitude of their weight-loss data, with blunt notes on what remains investigational.
- Best overall
- Retatrutide — The GIP/GLP-1/glucagon triple agonist produced the largest pharmacologic weight loss ever recorded — up to ~28–30% in Phase 3 TRIUMPH-1 — but remains investigational and trial-only.
- Best value
- Mazdutide — The single most regulatorily mature agent on the list: actually approved (China) and purchasable there, with mature Phase 3 obesity and diabetes data — though efficacy is dominated by younger, lower-BMI Chinese cohorts.
- Best for Co-existing liver disease (MASH/MASLD)
- Survodutide — Its distinctive value is the liver program — Phase 2 MASH data earned FDA Breakthrough Therapy, with ~63% liver-fat reduction and relative lean-mass preservation in SYNCHRONIZE-1.
How we evaluated
Agents were ranked by the strength, maturity, and magnitude of their human weight-loss evidence, not by hype or availability. Every entry is supported by published human randomized controlled trials; we separated completed Phase 3 from Phase 2, reported weight loss strictly as seen in the trials, and were explicit where an agent is unapproved, approved only in China, or trails the approved benchmarks (semaglutide, tirzepatide). This is informational and editorial content — not medical advice and not a sourcing guide.
- Evidence strength & maturity. Completed Phase 3 RCTs outrank Phase 2; trials published in NEJM/Lancet/Nature outrank press toplines and secondary coverage.
- Magnitude of weight loss. Mean percentage weight reduction over the trial duration, judged against the approved benchmarks of semaglutide (~15%) and tirzepatide (~21%).
- Mechanistic rationale. How the agent stacks GLP-1, GIP, glucagon, and/or amylin signaling, and whether comparator arms proved each added mechanism contributes.
- Regulatory & access reality. FDA/EMA/NMPA approval status, compounding eligibility, and WADA standing — strong evidence does not equal legal availability.
- Honest safety & limitations. Dose-related GI events, heart-rate rise, lean-mass loss, and head-to-head losses are reported even when they weaken the case.
Rating scale: 1–5 stars reflecting combined evidence strength, weight-loss magnitude, and regulatory maturity for weight loss specifically. Not a safety or recommendation score.
Last verified .
At a glance
| # | Name | Evidence | Rating | Best for | Pricing |
|---|---|---|---|---|---|
| 1 | Retatrutide (LY3437943) | A | 5.0 | Understanding the maximum weight loss the next-gen incretin class can achieve — strictly as published trial data, not an available option | No legal retail price (trial-only / investigational) |
| 2 | CagriSema (cagrilintide + semaglutide) | A | 4.5 | Following the most mature investigational combination — the amylin-plus-GLP-1 approach nearest to a US regulatory decision | No legal retail price (NDA filed; not yet approved) |
| 3 | Mazdutide (IBI362 / LY3305677) | A | 4.0 | Seeing what an approved next-gen dual agonist looks like in practice, with the China-cohort caveat front and center | Approved & purchasable in China only; no US price |
| 4 | Survodutide (BI 456906) | A | 4.0 | The metabolic-liver overlap — patients and clinicians watching MASH/MASLD, where survodutide's evidence is strongest | No legal retail price (filing anticipated ~2027) |
| 5 | Cagrilintide (AM833, monotherapy) | A | 3.5 | Understanding why amylin co-agonism matters — cagrilintide's value is as a partner, not a solo agent | No legal retail price (filed only within CagriSema) |
Retatrutide (LY3437943)
The triple agonist — largest weight loss ever recorded
Eli Lilly's investigational once-weekly subcutaneous 'triple-G' agonist activates the GIP, GLP-1, and glucagon receptors simultaneously, adding glucagon-driven energy expenditure and hepatic fat oxidation to the dual-incretin template of tirzepatide. The human evidence is genuine Grade A and now includes Phase 3. The Phase 2 trial (NEJM 2023, n=338, 48 weeks) produced weight loss of −8.7% / −17.1% / −22.8% / −24.2% across 1/4/8/12 mg versus −2.1% placebo, with a curve that had not plateaued. Phase 3 TRIUMPH-1 (topline 2026, n=2,339, 80 weeks) reported mean reductions of 19.0% / 25.9% / 28.3% (4/9/12 mg); at 12 mg, 45.3% lost ≥30% of body weight, and high-BMI participants continued to ~30.3% (around 85 lb) at 104 weeks — sustained, progressive loss approaching bariatric-surgery range. A Phase 2a MASLD study showed up to −86% relative liver fat. The honest catch is regulatory, not scientific: it is the most potent metabolic agent studied to date, yet available only inside a clinical trial.
Strengths
- Largest pharmacologic weight loss recorded — up to ~28–30% in Phase 3, exceeding tirzepatide's ~21%
- Triple mechanism adds glucagon-driven energy expenditure and dramatic liver-fat reduction (up to ~86%)
- Grade A across weight, type 2 diabetes (HbA1c up to −2.02%), and knee-OA pain endpoints
- Weight-loss curve had not plateaued even at 48–104 weeks
Weaknesses
- Investigational; not FDA-approved, not compoundable, and only available inside a registered trial
- Dose-related GI events (nausea 43%, diarrhea 33% at 12 mg), heart-rate rise, and a relatively retatrutide-specific dysesthesia (~21%)
- WADA-prohibited at all times (S0 + S2.4); full Phase 3 safety database still maturing
- Best for
- Understanding the maximum weight loss the next-gen incretin class can achieve — strictly as published trial data, not an available option
- Pricing
- No legal retail price (trial-only / investigational)
CagriSema (cagrilintide + semaglutide)
Amylin + GLP-1 combination — NDA filed, proof that amylin adds
Novo Nordisk's investigational once-weekly co-formulated pen combines cagrilintide, a long-acting amylin analogue, with semaglutide, the GLP-1 agonist in Wegovy — and it is the first drug to prove in humans that amylin co-agonism adds to GLP-1. The evidence base is among the deepest in the entire peptide field, with more than 8,000 randomized participants across NEJM and Lancet Phase 3 trials. REDEFINE 1 (n=3,417, 68 weeks, obesity without type 2 diabetes) showed −22.7% on the adherence estimand versus −2.3% placebo, with clear additivity: CagriSema −22.7% beat semaglutide alone (~−16%) and cagrilintide alone (~−12%). REDEFINE 2 (obesity plus diabetes) reached −13.7% with strong glycemic control. The honest nuance is that −22.7% undershot Novo Nordisk's own ≥25% guidance — partly because a tolerability-driven dose-reduction protocol meant only 57.3% reached the top dose — and in the REDEFINE 4 head-to-head, CagriSema (−23.0%) did NOT meet non-inferiority to tirzepatide (−25.5%). It is a strong but not class-leading agent.
Strengths
- Massive Phase 3 evidence base (>8,000 randomized participants in NEJM/Lancet trials)
- First human proof that amylin co-agonism is additive to GLP-1 — comparator arms confirmed it
- FDA NDA filed Dec 18, 2025, with a decision expected ~late 2026 — the closest to approval of the investigational group
- Mostly transient, GI-dominant tolerability profile with low AE-driven discontinuation (6.0%)
Weaknesses
- Undershot Novo Nordisk's ≥25% guidance and lost the head-to-head to tirzepatide (REDEFINE 4)
- Not approved anywhere yet; not legally compoundable
- ~14% of weight lost was lean soft tissue; GI events affected ~79.6% of participants
- Best for
- Following the most mature investigational combination — the amylin-plus-GLP-1 approach nearest to a US regulatory decision
- Pricing
- No legal retail price (NDA filed; not yet approved)
Mazdutide (IBI362 / LY3305677)
The only one approved (China) — GLP-1/glucagon dual agonist
Mazdutide is an acylated oxyntomodulin-analogue dual agonist of the GLP-1 and glucagon receptors, co-developed by Innovent and Eli Lilly, and the single most regulatorily mature agent on this list — it is actually approved, in China. Its Phase 3 program is mature in both obesity (GLORY series) and diabetes (DREAMS series). GLORY-1 (n=610, 48 weeks) showed weight change of −12.05% (4 mg) and −14.84% (6 mg) versus −0.47% placebo, with hepatic fat falling 65.9% to 80.2%. GLORY-2 (9 mg, 60 weeks) reached about 20.1% weight loss in the non-diabetic subgroup, with no plateau at 60 weeks. In diabetes, DREAMS-3 beat semaglutide 1 mg on a composite endpoint. The single most important caveat is generalizability: the efficacy data are dominated by younger, lower-BMI Chinese cohorts, so extrapolation to Western populations is unproven. It is approved by China's NMPA (obesity June 2025; type 2 diabetes September 2025) but is not FDA-approved — US development is only at Phase 2, with potential US approval around 2028–29.
Strengths
- The only ranked agent with an actual regulatory approval (China NMPA, 2025) — purchasable there
- Mature Phase 3 data in both obesity (~20% at 9 mg) and diabetes, with large hepatic-fat reductions
- Glucagon arm adds energy expenditure on top of GLP-1 appetite suppression
- Beat semaglutide 1 mg on a composite endpoint in DREAMS-3
Weaknesses
- Efficacy data dominated by younger, lower-BMI Chinese cohorts — Western generalizability unproven
- Not FDA-approved; US development only at Phase 2 (potential approval ~2028–29)
- Immunogenicity signal, including one glucagon-receptor neutralizing antibody — a durability consideration
- Best for
- Seeing what an approved next-gen dual agonist looks like in practice, with the China-cohort caveat front and center
- Pricing
- Approved & purchasable in China only; no US price
Source: Ji et al., GLORY-1, NEJM 2025
Survodutide (BI 456906)
GLP-1/glucagon dual agonist — MASH Breakthrough Therapy
Survodutide is Boehringer Ingelheim and Zealand Pharma's investigational once-weekly GLP-1 plus glucagon dual agonist, built on a glucagon backbone with an approximately 8-fold GLP-1R bias and a half-life around 6 days. Its obesity program is now complete through Phase 3, and its liver-disease data are its distinctive feature. SYNCHRONIZE-1 (n=725, 76 weeks) showed −16.6% at 6.0 mg on the efficacy estimand versus −3.2% placebo, with 28.5% of participants losing ≥20%; notably, the loss skewed to fat mass with relative lean-mass preservation, visceral fat fell about 34%, and liver fat fell about 63%. The Phase 2 obesity trial reached up to −14.9%. Most striking is the MASH program: a Phase 2 trial (NEJM 2024, n=293) saw 62% achieve MASH improvement without fibrosis worsening at 4.8 mg versus 14% placebo, which earned FDA Breakthrough Therapy and Fast Track plus EMA PRIME. Honestly, its ~16.6% places it ahead of semaglutide (~15%) but below tirzepatide (~21%) and below retatrutide and CagriSema — a solid but not class-leading weight agent whose real value is the liver/MASH story.
Strengths
- Standout liver/MASH program — FDA Breakthrough Therapy + Fast Track and EMA PRIME designations
- Relative lean-mass preservation with weight loss skewed to fat, plus ~63% liver-fat reduction
- Completed Phase 3 obesity data (SYNCHRONIZE-1, −16.6%) published and presented at ADA 2026
- Dose-dependent blood-pressure reduction observed in Phase 2
Weaknesses
- Weight loss (~16.6%) trails tirzepatide, retatrutide, and CagriSema — not class-leading
- Not approved anywhere as of mid-2026; filing only anticipated ~2027
- GI-dominant AEs in ~75% of participants; WADA-prohibited as a non-approved substance (S0)
- Best for
- The metabolic-liver overlap — patients and clinicians watching MASH/MASLD, where survodutide's evidence is strongest
- Pricing
- No legal retail price (filing anticipated ~2027)
Cagrilintide (AM833, monotherapy)
The amylin pillar — modest alone, powerful as a partner
Cagrilintide is the standalone long-acting amylin/calcitonin-receptor agonist that forms the amylin half of CagriSema — a 37-amino-acid analogue redesigned to resist amyloid fibrillation, with a half-life of roughly 7–8 days, a dramatic improvement over pramlintide's 20–45 minutes. Its monotherapy evidence is real but modest. The Phase 2 trial (Lau et al., Lancet 2021, n=906, 26 weeks) showed dose-dependent weight loss from 6.0% (0.3 mg) up to 10.8% (4.5 mg) versus 3.0% placebo, with the 4.5 mg dose modestly beating liraglutide 3.0 mg (10.8% vs 9.0%). As a Phase 3 component arm in REDEFINE 1, cagrilintide 2.4 mg alone delivered 11.8% — meaningful, but below semaglutide alone (16.1%) and far below the combination (22.7%). The honest verdict is that as a stand-alone fat-loss peptide, cagrilintide is the weaker story; its overwhelming value is as a combination partner, the amylin co-pathway that makes CagriSema additive. It is the proof-of-concept for the entire next-generation amylin class, including emerging agents like petrelintide and amycretin. It is not approved, is explicitly ineligible for compounding, and is filed only as part of CagriSema.
Strengths
- Real Phase 2 and Phase 3 human RCT data (Grade A), unusual for a single peptide
- Engineering breakthrough — half-life of ~7–8 days enables once-weekly dosing vs pramlintide's minutes
- Proof-of-concept for the amylin class and the additive partner that makes CagriSema work
- Modestly beat liraglutide 3.0 mg head-to-head at 4.5 mg in Phase 2
Weaknesses
- Modest as monotherapy (~10.8–11.8%) — below semaglutide alone and the combination
- Not approved; explicitly ineligible for compounding; filed only as part of CagriSema
- Long-term safety still awaits longer trials; GI events 41–63% plus injection-site reactions
- Best for
- Understanding why amylin co-agonism matters — cagrilintide's value is as a partner, not a solo agent
- Pricing
- No legal retail price (filed only within CagriSema)
Source: Lau et al., Cagrilintide Phase 2, Lancet 2021 (PMID 34798060)
Frequently asked
Are any of these next-gen peptides actually available to buy legally in the US?
No. As of mid-2026, retatrutide, survodutide, cagrilintide, and CagriSema are investigational and not FDA-approved; mazdutide is approved only in China; none can be legally compounded by a US pharmacy. The FDA has explicitly stated that retatrutide and cagrilintide cannot be used in compounding. The lawful US options are approved drugs — semaglutide, tirzepatide, and the new oral non-peptide orforglipron — or enrollment in a registered clinical trial. Material sold online as 'research chemical / not for human use' is unapproved, frequently mislabeled or contaminated, and the trial efficacy and safety data do not transfer to it.
Which next-gen peptide produces the most weight loss?
On current data, retatrutide — the GIP/GLP-1/glucagon triple agonist. Phase 3 TRIUMPH-1 reported mean weight reduction up to about 28.3% at 12 mg over 80 weeks, with high-BMI participants reaching roughly 30.3% (around 85 lb) by 104 weeks — the largest pharmacologic weight loss recorded, exceeding tirzepatide's roughly 21%. CagriSema (about 22.7% in REDEFINE 1) and mazdutide 9 mg (about 20%) follow. Importantly, CagriSema lost the head-to-head to tirzepatide in REDEFINE 4, so 'newer' does not automatically mean better, and retatrutide is the least regulatorily mature of the group.
Are these GLP-1 'alternatives' or just GLP-1 'plus' therapies?
Mostly the latter, and the distinction is honest framing. 'Alternative to GLP-1' is partly a misnomer: most of these agents contain or build on GLP-1 agonism and add a second or third mechanism — the glucagon receptor, the GIP receptor, or the amylin receptor — on top of it. They are better understood as GLP-1-plus therapies than as GLP-1 replacements. The combinatorial strategy is the point: stacking two or three satiety and energy-expenditure mechanisms in one weekly injection is how these drugs exceed the roughly 15–21% weight-loss ceiling of single-mechanism agents like semaglutide and tirzepatide.
Does newer automatically mean better than tirzepatide?
No, and the trials are clear on this. CagriSema failed non-inferiority to tirzepatide in the REDEFINE 4 head-to-head (−23.0% vs −25.5%), and survodutide's roughly 16.6% trails tirzepatide's roughly 21%. Only retatrutide has clearly exceeded tirzepatide on weight loss in its own trials — and it is the least-approved of the group. For most people in 2026, the genuine, legal alternatives to a single GLP-1 are tirzepatide, the new oral orforglipron, or a clinical trial — not a peptide ordered online. Strong investigational evidence does not equal a better, available option today.
What are the main safety concerns shared across this class?
Gastrointestinal adverse events dominate — nausea, vomiting, diarrhea, constipation, and decreased appetite — and are dose-related, mostly mild-to-moderate, and concentrated during titration, with slower dose escalation reducing discontinuations. A modest heart-rate increase of a few beats per minute is seen across the incretin class. Meaningful lean-mass loss accompanies fat loss, so adequate protein and resistance training matter. The glucagon-arm agents (retatrutide, survodutide, mazdutide) additionally raise ketones and warrant glucose and hepatic monitoring. Class GLP-1 cautions apply: personal or family history of medullary thyroid carcinoma or MEN2, pancreatitis, and gallbladder disease; pregnancy and breastfeeding are clear contraindications.
Is the evidence here stronger than for typical research peptides like BPC-157?
Far stronger, and this distinction is the whole point of the ranking. Most of the peptide field — BPC-157, TB-500, and the body-composition peptides — rests on animal models, in-vitro work, or anecdote. By contrast, every agent ranked here has completed human randomized controlled trials, most of them Phase 3, published in NEJM, Lancet, or Nature, and grades to evidence level A for weight loss. This is the one corner of peptide science where the human data are genuinely robust. The catch is regulatory, not scientific: strong evidence does not equal legal availability.