Retatrutide's Phase 3 Data Just Set a New Bar — And CagriSema Isn't Far Behind

Why this matters

For the last few years, the GLP-1 conversation has centered on two approved drugs: semaglutide and tirzepatide. This year brought the first real Phase 3 evidence that the next generation of these drugs may go meaningfully further. On May 21, 2026, Eli Lilly announced topline results from TRIUMPH-1, the first completed pivotal trial for its investigational triple agonist retatrutide — and the weight-loss numbers were the highest reported for any drug in this class to date. Separately, Novo Nordisk's CagriSema (cagrilintide plus semaglutide) has finished its own pivotal obesity program and is already sitting with the FDA, awaiting a decision.

Neither drug is approved. Both are still investigational. But both now have real, randomized, placebo-controlled Phase 3 data behind them instead of early-phase signals — which is the point where "promising" starts to become "worth tracking closely."

What retatrutide's TRIUMPH-1 trial found

Retatrutide is a first-in-class triple hormone receptor agonist, activating receptors for GIP, GLP-1, and glucagon at once — one more mechanism than tirzepatide (GIP/GLP-1) and two more than semaglutide (GLP-1 only). TRIUMPH-1 was an 80-week, randomized, double-blind, placebo-controlled trial of 2,339 adults with obesity or overweight and at least one weight-related condition, without diabetes.

All three tested doses met the trial's primary and key secondary endpoints:

• 12 mg (highest dose): average weight loss of 70.3 lb, or 28.3%, at 80 weeks — from an average starting weight of 248.5 lb. 45.3% of participants on this dose lost 30% or more of their body weight, a threshold historically associated with bariatric surgery. 65.3% brought their BMI below the threshold for obesity by week 80.
• 9 mg: average loss of 64.4 lb, or 25.9%.
• 4 mg (reached with a single dose-escalation step): average loss of 47.2 lb, or 19.0%.

A prespecified extension followed 532 participants with a baseline BMI of 35 or higher out to 104 weeks. Those who started on the 12 mg arm reached an average total loss of 85.0 lb — 30.3% of their starting body weight — with no clear plateau in sight. The 12 mg group also saw an average waist circumference reduction of 24.1 cm (about 9.5 inches), alongside improvements in triglycerides, non-HDL cholesterol, systolic blood pressure, and a marker of inflammation (high-sensitivity C-reactive protein).

Where CagriSema's pivotal program stands

CagriSema is a fixed-dose combination of cagrilintide (an amylin receptor agonist) and semaglutide (the GLP-1 already sold as Ozempic and Wegovy) — a different strategy from retatrutide's triple-receptor approach, pairing two established mechanisms instead of adding a third. Its obesity program, REDEFINE, has already completed its two pivotal trials.

REDEFINE 1, published in The New England Journal of Medicine, enrolled 3,417 adults with obesity or overweight (without type 2 diabetes) and ran 68 weeks. On the trial-product estimand — the analysis that reflects treatment effect while participants stayed on assigned therapy — CagriSema produced an average weight loss of 22.7%, compared with 16.1% for semaglutide 2.4 mg alone, 11.8% for cagrilintide 2.4 mg alone, and 2.3% for placebo. Among participants who stayed on treatment, 60.2% lost 20% or more of their body weight, and 23.1% lost 30% or more.

A second pivotal trial, REDEFINE 2, tested CagriSema in adults with obesity and type 2 diabetes, reporting roughly 15.7% weight loss at 68 weeks — a smaller number than REDEFINE 1, consistent with the pattern seen across this drug class, in which weight loss tends to be more modest in people who also have diabetes.

Novo Nordisk submitted CagriSema to the FDA for chronic weight management in December 2025, based on the REDEFINE 1 and REDEFINE 2 pivotal data. A standard FDA review cycle runs about ten months from filing, which would put a decision in the back half of 2026 — though the agency has not published a confirmed target action date, so that timing is an estimate, not a commitment.

How the two compare — and what the comparison can't tell you

Side by side, retatrutide's 12 mg dose produced a larger average weight loss (28.3% at 80 weeks) than CagriSema's 22.7% at 68 weeks. But the two numbers come from separate trials, run in different participant populations, on different timelines, without a head-to-head design. Nothing here proves retatrutide "beats" CagriSema for an individual patient — cross-trial comparisons in obesity medicine have a long history of not holding up once drugs are finally tested against each other directly.

What it can't say yet

• Neither drug is approved. Retatrutide has not been submitted for weight management yet; Lilly says a regulatory filing is expected before year-end. CagriSema is under review, not cleared.
• No head-to-head trial exists between retatrutide and CagriSema. The percentages above cannot be read as a direct competition.
• Retatrutide's full program isn't finished. TRIUMPH-2 (obesity plus type 2 diabetes) and TRIUMPH-3 (obesity plus established cardiovascular disease) haven't reported yet, and those populations often see different results than the general obesity population studied in TRIUMPH-1.
• Longer-term safety is still being established for both drugs — the discontinuation and side-effect data above reflect the trial period only.

Why it matters for this audience

Weight management gets harder to talk about honestly in perimenopause and menopause, when hormonal shifts change body composition independent of diet and exercise. Bigger average weight-loss numbers in trials are genuinely notable for women weighing their options with a doctor — but bigger numbers also mean bigger average side-effect burden, which matters more for anyone already managing menopause-related GI sensitivity, bone density concerns, or muscle loss. None of that is a reason to avoid these drugs; it's a reason to have the conversation with a clinician who knows the full picture, not just the headline percentage.

What's next

Lilly plans to present detailed TRIUMPH-1 data at the American Diabetes Association's Scientific Sessions, with TRIUMPH-2 and TRIUMPH-3 results expected later in 2026 and a regulatory filing for retatrutide anticipated before year-end. On the CagriSema side, the FDA's decision on the December 2025 filing is the next concrete milestone — we'll update this story once either agency action lands.