Investigational · not FDA approved

Editorially reviewed · Last updated February 2026 · How we review

Retatrutide vs CagriSema (Cagrilintide + Semaglutide): Triple Agonist vs Amylin + GLP-1 Combo

Retatrutide and CagriSema represent two fundamentally different approaches to next-generation obesity treatment. Retatrutide is a single molecule that activates three receptors (GLP-1, GIP, and glucagon). CagriSema is a combination of two separate drugs — cagrilintide (an amylin analog) and semaglutide (a GLP-1 agonist) — delivered together in one injection.

Both are made by different companies (Eli Lilly vs Novo Nordisk), target different biological pathways, and have reported Phase 3 results. CagriSema is further along in the regulatory process, with an NDA filed in December 2025. Retatrutide is still completing Phase 3 trials.

Side-by-Side Comparison

	Retatrutide	CagriSema
Developer	Eli Lilly	Novo Nordisk
Mechanism	Triple agonist: GLP-1 + GIP + Glucagon	Combination: Amylin analog (cagrilintide) + GLP-1 agonist (semaglutide)
Administration	Once-weekly injection (single peptide)	Once-weekly injection (two peptides in one)
Max weight loss (Phase 3)	-28.7% at 68 weeks (TRIUMPH-4, 12 mg)	-22.7% at 68 weeks (REDEFINE 1)
Phase 3 program	TRIUMPH (first readout Dec 2025)	REDEFINE (multiple trials completed)
FDA filing	Not yet filed	NDA submitted December 2025
Expected approval	2027 at earliest	2026
GI side effects	Similar to GLP-1 class	~80% (mild-moderate, transient)
Unique safety signal	Dysesthesia (8.8-20.9%)	None beyond GI class effects
Discontinuation (AEs)	12-18% (Phase 3)	~6% (REDEFINE 1)

Cagrilintide vs Retatrutide: How the Mechanisms Differ

Retatrutide: Three Receptors, One Molecule

Retatrutide activates GLP-1, GIP, and glucagon receptors simultaneously with a single peptide molecule. The glucagon component is what sets it apart — it increases energy expenditure through thermogenesis and promotes fat oxidation, particularly in the liver. This means retatrutide attacks obesity from both sides of the energy equation: reduced intake (GLP-1 + GIP) and increased expenditure (glucagon).

For details on each receptor, see How Does Retatrutide Work?.

CagriSema: Two Drugs Working Together

CagriSema combines two separate mechanisms:

Cagrilintide (2.4 mg) is a long-acting analog of amylin, a hormone co-secreted with insulin from pancreatic beta cells after meals. Amylin promotes satiety by acting on both homeostatic and hedonic (reward) brain regions via the area postrema. It slows gastric emptying and suppresses post-meal glucagon secretion. Cagrilintide is engineered with prolonged action through reversible albumin binding, enabling once-weekly dosing.

Semaglutide (2.4 mg) is the same GLP-1 agonist in Wegovy/Ozempic — the most well-established obesity drug on the market.

The combination targets appetite through two complementary brain pathways (amylin + GLP-1), producing additive weight loss beyond what either component achieves alone. In REDEFINE 1, CagriSema (-22.7%) significantly outperformed both cagrilintide alone (-11.8%) and semaglutide alone (-16.1%).

The Key Difference

Retatrutide includes glucagon receptor agonism, which increases energy expenditure — your body burns more calories at rest. CagriSema does not increase energy expenditure. Instead, it stacks two different appetite suppression pathways (amylin + GLP-1).

This likely explains why retatrutide produces greater maximum weight loss (-28.7% vs -22.7%) — the glucagon component adds thermogenic effects on top of appetite reduction.

Cagrilintide vs Retatrutide vs Tirzepatide: Receptor Targets

Receptor	Retatrutide	CagriSema	Tirzepatide (Zepbound)
GLP-1	Yes	Yes (via semaglutide)	Yes
GIP	Yes	No	Yes
Glucagon	Yes	No	No
Amylin	No	Yes (via cagrilintide)	No
Total pathways	3	2	2
Max weight loss	-28.7%	-22.7%	-22.5%

Retatrutide and CagriSema each cover pathways the other does not. Retatrutide has GIP and glucagon but no amylin agonism. CagriSema has amylin agonism but no GIP or glucagon. Tirzepatide overlaps with retatrutide on GLP-1 and GIP but lacks both glucagon and amylin.

Weight Loss Comparison

Phase 3 Results

Drug	Trial	Duration	Weight Loss	Participants
Retatrutide 12 mg	TRIUMPH-4	68 weeks	-28.7%	445
Retatrutide 9 mg	TRIUMPH-4	68 weeks	-26.4%	445
CagriSema	REDEFINE 1	68 weeks	-22.7%	3,417
Semaglutide 2.4 mg alone	REDEFINE 1	68 weeks	-16.1%	3,417
Cagrilintide 2.4 mg alone	REDEFINE 1	68 weeks	-11.8%	3,417

Weight Loss Thresholds (CagriSema, REDEFINE 1)

Threshold	CagriSema	Semaglutide Alone
Lost at least 5%	91.9%	—
Lost at least 20%	~60%	—
Lost at least 25%	34.7%	—
Lost at least 30%	~23%	—

CagriSema in Type 2 Diabetes (REDEFINE 2)

In adults with type 2 diabetes, CagriSema produced -15.7% weight loss at 68 weeks vs -3.1% for placebo. Weight loss is consistently lower in diabetic populations across all GLP-1 class drugs. Retatrutide's dedicated T2D Phase 3 program (TRANSCEND) has not yet reported results.

Important Caveat

These results come from different trials with different patient populations. TRIUMPH-4 enrolled patients with obesity and knee osteoarthritis (445 participants). REDEFINE 1 enrolled a broader obesity population (3,417 participants). The only definitive comparison would be a randomized head-to-head trial, which does not exist.

Side Effects and Tolerability

	Retatrutide (TRIUMPH-4)	CagriSema (REDEFINE 1)
Most common	Nausea, diarrhea, constipation, vomiting	Nausea, vomiting, diarrhea, constipation, abdominal pain
GI event rate	Consistent with GLP-1 class	~80% (vs ~40% placebo)
Severity	Mostly mild-moderate	Mostly mild-moderate, transient
Discontinuation (AEs)	12-18%	~6% (vs 3.7% placebo)
Unique signal	Dysesthesia (tingling/burning) in 8.8-20.9%	None beyond GI class effects

CagriSema's lower discontinuation rate (~6%) compared to retatrutide (12-18%) is notable. Retatrutide's unique dysesthesia signal — tingling, burning, or prickling sensations on the skin — occurred in up to 20.9% of participants on the 12 mg dose and is being monitored in ongoing trials. This is likely related to the glucagon receptor and is not seen with CagriSema or other GLP-1 drugs.

Regulatory Timeline

Milestone	CagriSema	Retatrutide
Phase 3 program	REDEFINE (multiple trials completed)	TRIUMPH (first readout Dec 2025)
NDA filed	December 18, 2025	Not yet filed
FDA review	Under review, decision expected 2026	—
Expected approval	Late 2026	2027 at earliest
Head-to-head trial	REDEFINE 4: CagriSema vs tirzepatide (results pending)	None against CagriSema

CagriSema is approximately one year ahead of retatrutide in the regulatory timeline. If approved in 2026, it would be the first amylin + GLP-1 combination therapy on the market.

Can You Combine Cagrilintide With Retatrutide?

People searching for "cagrilintide with retatrutide" or "cagrilintide and retatrutide together" are asking about stacking these two peptides. Here is what the evidence says.

The Scientific Rationale

There is a plausible theoretical basis for combining them. Cagrilintide activates amylin receptors — a pathway that retatrutide does not touch. Together, they would cover four distinct receptor systems (GLP-1, GIP, glucagon, and amylin), potentially producing greater appetite suppression and weight loss than either drug alone.

This rationale is supported by CagriSema's own clinical data. In REDEFINE 1, adding cagrilintide to semaglutide produced 22.7% weight loss compared to 16.1% for semaglutide alone — demonstrating that amylin agonism meaningfully enhances GLP-1-based weight loss. In principle, the same additive effect could apply to retatrutide.

Eli Lilly appears to recognize this logic. The company is studying eloralintide, its own amylin receptor agonist, in combination with tirzepatide in a Phase 2 trial — suggesting that amylin + incretin combinations are an active area of pharmaceutical development.

What the Data Actually Shows

No clinical trial has studied cagrilintide and retatrutide together. Zero published safety or efficacy data exists for this combination. The two drugs are made by competing companies (Novo Nordisk and Eli Lilly), making a formal combination study unlikely.

Safety Concerns

Without clinical data, safety risks can only be inferred:

Additive GI side effects — both drugs slow gastric emptying through different mechanisms. Combining them could increase nausea, vomiting, and gastroparesis risk beyond what either drug causes alone.
Excessive appetite suppression — amylin agonism is a potent appetite suppressant. Combined with retatrutide's triple mechanism, caloric intake could drop to levels that promote muscle loss and nutritional deficiencies.
No long-term safety data — neither drug has multi-year safety data on its own, let alone in combination.

The Bottom Line

The scientific rationale for combining amylin agonism with incretin-based therapy is real and supported by CagriSema's clinical results. However, no data exists for the specific cagrilintide + retatrutide combination. Anyone considering this combination should discuss it with their physician.

Frequently Asked Questions

Which produces more weight loss — retatrutide or CagriSema?

Based on Phase 3 data, retatrutide produces greater maximum weight loss (-28.7% vs -22.7% at 68 weeks). However, these results come from different trials with different populations. A head-to-head comparison has not been conducted.

Is CagriSema just Wegovy plus another drug?

Essentially, yes. CagriSema combines semaglutide (the active ingredient in Wegovy) with cagrilintide, a long-acting amylin analog. The combination produces about 6-7 percentage points more weight loss than semaglutide alone.

What is amylin and why does it help with weight loss?

Amylin is a hormone co-secreted with insulin from pancreatic beta cells after meals. It promotes satiety by acting on brain regions involved in both hunger signaling (homeostatic) and food reward/craving (hedonic). It also slows gastric emptying and suppresses post-meal glucagon. Cagrilintide is an engineered long-acting version of amylin.

Will CagriSema be available before retatrutide?

Most likely, yes. Novo Nordisk filed an NDA for CagriSema in December 2025, with FDA approval expected in 2026. Retatrutide has not yet been filed and is expected to reach the market in 2027 at the earliest.

Can you take CagriSema while waiting for retatrutide?

This would be a decision for your doctor. CagriSema, if approved, would be an option for patients who cannot wait for retatrutide. Switching protocols between the two drugs have not been studied.

Can you stack cagrilintide with retatrutide?

There is a plausible scientific rationale — cagrilintide targets amylin receptors, which retatrutide does not — but no clinical trial has studied this combination. The two drugs are made by competing companies (Novo Nordisk vs Eli Lilly). Safety data for combining them does not exist, and additive GI side effects are a concern. Discuss any combination therapy with your physician.

How does cagrilintide compare to retatrutide for weight loss?

Cagrilintide alone produced 11.8% weight loss at 68 weeks in REDEFINE 1. Retatrutide produced 28.7% at 68 weeks in TRIUMPH-4. However, cagrilintide is designed to work in combination with semaglutide (as CagriSema, 22.7% weight loss), not as a standalone drug. The comparison is retatrutide (one triple agonist molecule) vs CagriSema (two drugs combined).

Is cagrilintide a GLP-1 drug?

No. Cagrilintide is an amylin analog, not a GLP-1 agonist. Amylin is a separate hormone co-secreted with insulin from pancreatic beta cells. Cagrilintide works through amylin and calcitonin receptors, which are distinct from the GLP-1, GIP, and glucagon receptors that retatrutide targets.

Sources

Novo Nordisk. (2025). Novo Nordisk files for FDA approval of CagriSema. Press release.
Aronne, L.J., et al. (2025). Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. DOI: 10.1056/NEJMoa2502081
Novo Nordisk. (2025). REDEFINE 2 results. GlobeNewsWire.
Eli Lilly. (2025). TRIUMPH-4 results. Press release.
Sonne, N., et al. (2025). Amylin — mode of action, from bench side to clinical potential. Diabetologia. PMC12085449
Chung, J.S., et al. (2025). Triple agonism based therapies for obesity. Springer. PMC12304053

How we keep this honest

What this is: Educational information, not medical advice. It reports published research — it doesn’t recommend that you use, obtain, or supply anything.
Regulatory status: Retatrutide and similar peptides are investigational — not approved by the FDA or any regulator. Semaglutide and tirzepatide are prescription-only medicines, available only through a licensed prescriber.
Our standard: Every claim traces to a primary source. We label the strength of evidence and flag estimates as estimates — never as clinical fact.
No commercial ties: We don’t sell, supply, or link to suppliers of any medicine, and aren’t affiliated with any manufacturer.

Do not make decisions about your health without consulting a qualified healthcare provider. For trial enrolment, see ClinicalTrials.gov. More on how we review.

Sources