Retatrutide vs CagriSema
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: LY3437943, Triple G
Retatrutide is the heavy hitter of the new weight-loss drugs: a once-weekly injectable peptide that hits three receptors at once - GIP, GLP-1, and glucagon - earning it the nickname triple-G agonist. In a phase 2 trial it produced some of the largest weight loss ever recorded for a drug, up to roughly 24 percent of body weight at the top dose. It is investigational, made by Eli Lilly, and not yet FDA approved as of 2026.
Also: Semaglutide + Cagrilintide
CagriSema is a once-weekly injectable that pairs two drugs in one shot: semaglutide (a GLP-1 receptor agonist, the molecule behind Ozempic and Wegovy) and cagrilintide (a long-acting amylin analog). It is being developed by Novo Nordisk for obesity and type 2 diabetes, and in 2025 it cleared its phase 3 REDEFINE trials. It is not yet approved by the FDA, though regulatory filings are underway.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | Retatrutide | CagriSema |
|---|---|---|
| Category | Weight Loss | Weight Loss |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | Retatrutide combines three hormone signals into one molecule. The GLP-1 component curbs appetite and slows stomach emptying, the GIP component supports insulin response and may improve how fat tissue handles nutrients, and the added glucagon receptor activity is the novel piece: glucagon can increase energy expenditure and fat burning in the liver. The idea is that two arms cut how much you eat while the third raises how much you burn, which is why retatrutide is thought to push weight loss further than GLP-1-only drugs like semaglutide or even the dual GIP/GLP-1 agonist tirzepatide. The exact contribution of each receptor in humans is still being worked out, so consider the glucagon-driven energy-expenditure story a strong hypothesis rather than fully nailed down. | The combination works on two different appetite systems at once. Semaglutide mimics GLP-1, a gut hormone that boosts insulin after meals, slows stomach emptying, and signals fullness to the brain. Cagrilintide is a synthetic version of amylin, a hormone co-secreted with insulin from the pancreas, which reduces food intake and reinforces satiety through separate brain circuits in the hindbrain and hypothalamus. The idea, still being characterized, is that hitting GLP-1 and amylin pathways together produces more appetite suppression than either alone. Both components are engineered for slow release so a single weekly dose maintains steady drug levels. |
| Common Dosing | 4-12 mg weekly Once weekly, same day each week | Limited community data available See research protocols |
| Administration | Subcutaneous injection weekly | Subcutaneous injection weekly |
| Typical Duration | Long-term use expected | Long-term use expected |
| Best Time to Take | Morning, same day each week | Before bed or morning (fasted) |
Possible Side Effects May vary by individual |
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| Research Summary | The key human evidence is the phase 2 trial by Jastreboff and colleagues, published in the New England Journal of Medicine in 2023, which randomized 338 adults with obesity (without type 2 diabetes) over 48 weeks. Mean weight reduction reached about 24 percent at the 12 mg dose, and weight loss had not clearly plateaued by week 48, hinting the ceiling could be even higher. Among participants with prediabetes at baseline, a large majority returned to normal blood sugar. Side effects were dominated by gastrointestinal issues like nausea, vomiting, and diarrhea, the familiar pattern for this drug class, and were mostly dose-dependent. These are genuinely strong phase 2 results, but they are phase 2: larger and longer phase 3 trials are underway to confirm safety and durability, and retatrutide sold outside of trials is not an approved, quality-controlled medicine. | This is one of the better-tested experimental obesity drugs because it went straight into large human phase 3 trials rather than living only in animal data. In REDEFINE 1, about 3,400 adults with overweight or obesity but without diabetes were randomized over 68 weeks; CagriSema produced roughly 20.4% average body weight loss versus 14.9% for semaglutide alone, 11.5% for cagrilintide alone, and 3.0% for placebo, with results published in the New England Journal of Medicine in 2025. REDEFINE 2 tested it in adults with type 2 diabetes and also met its endpoints, showing meaningful weight loss and HbA1c improvement compared with placebo. Notably, the headline 20% figure landed below Novo Nordisk's own 25% target, which disappointed investors even though the drug clearly worked. The most common side effects were gastrointestinal: nausea, vomiting, diarrhea, and constipation, consistent with the GLP-1 plus amylin class. CagriSema is not FDA-approved as of mid-2026, so anything sold under that name outside a clinical setting is unregulated. |
Frequently Asked Questions: Retatrutide vs CagriSema
What is the difference between Retatrutide and CagriSema?
Retatrutide is a weight loss peptide that retatrutide is the heavy hitter of the new weight-loss drugs: a once-weekly injectable peptide that hits three receptors at once - gip, glp-1, and glucagon - earning it the nickname triple-g agonist. in a phase 2 trial it produced some of the largest weight loss ever recorded for a drug, up to roughly 24 percent of body weight at the top dose. it is investigational, made by eli lilly, and not yet fda approved as of 2026. CagriSema is a weight loss peptide that cagrisema is a once-weekly injectable that pairs two drugs in one shot: semaglutide (a glp-1 receptor agonist, the molecule behind ozempic and wegovy) and cagrilintide (a long-acting amylin analog). it is being developed by novo nordisk for obesity and type 2 diabetes, and in 2025 it cleared its phase 3 redefine trials. it is not yet approved by the fda, though regulatory filings are underway. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Retatrutide or CagriSema?
Neither is universally "better" - the choice depends on your specific goals. Retatrutide is typically used for weight loss purposes, while CagriSema is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Retatrutide and CagriSema be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Retatrutide and CagriSema together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.