Tirzepatide vs Retatrutide vs CagriSema: Next-Gen GLP-1 Weight Loss Compared (2026)

The Three Medications at a Glance

**Tirzepatide (Zepbound, Mounjaro - Eli Lilly)**: Dual GLP-1/GIP receptor agonist. FDA-approved for obesity (Zepbound) in 2023 and type 2 diabetes (Mounjaro). Average 21% body weight loss at 72 weeks in SURMOUNT-1 trial. Current standard of care for severe obesity medication. Available now: $549-$1,059/month direct via LillyDirect, $1,059-$1,350 retail without insurance.

**Retatrutide (Eli Lilly - Phase 3, expected FDA approval 2027)**: Triple GLP-1/GIP/glucagon receptor agonist. Phase 2 trials showed 24.2% body weight loss at 48 weeks (highest documented in obesity medication trials). Phase 3 SURMOUNT-NEXT trial ongoing. Expected FDA approval 2027; commercial launch 2027-2028. Price unconfirmed but expected $700-$1,400/month direct.

**CagriSema (semaglutide + cagrilintide - Novo Nordisk)**: Combination of semaglutide (existing GLP-1 from Wegovy/Ozempic) with cagrilintide (amylin analog). Phase 3 REDEFINE trials reported 22.7% weight loss at 68 weeks - comparable to tirzepatide. Expected FDA submission 2026, approval 2027. Novo Nordisk's response to tirzepatide. Price expected to compete with tirzepatide.

Realistic Weight Loss Comparison

Average percent body weight loss at 68-72 weeks of treatment:

- Semaglutide (Wegovy 2.4mg): 14.9% weight loss (STEP-1 trial) - Liraglutide (Saxenda): 6-8% weight loss - Tirzepatide 15mg (Zepbound): 20.9% weight loss (SURMOUNT-1) - Retatrutide 12mg (Phase 2): 24.2% weight loss at 48 weeks - CagriSema (semaglutide + cagrilintide): 22.7% weight loss (REDEFINE-1) - Bariatric surgery (sleeve gastrectomy): 25-30% weight loss at 2 years

Realistic comparison: retatrutide and CagriSema both approach bariatric surgery effectiveness without surgical intervention. Tirzepatide is the current best-available without these still-investigational medications. Wegovy/semaglutide remains the standard cheaper option.

Individual patient response varies substantially. Some patients on tirzepatide achieve 25%+ weight loss; others achieve only 10-15%. Expected weight loss = approximately the trial average, but expect significant variance.

Cost Trajectory and Insurance

Current GLP-1 pricing (2026): - Wegovy 2.4mg: $1,349/month retail; ~$25-$300/month with insurance + savings card - Zepbound 15mg: $1,059/month direct via LillyDirect; ~$25-$300/month with insurance - Ozempic (used for weight loss off-label): $935/month retail - Mounjaro: $1,069/month retail

Expected next-gen pricing (when launched 2027-2028): - Retatrutide: estimated $1,200-$1,800/month at launch (premium pricing for newer agent) - CagriSema: estimated $1,000-$1,400/month at launch (compete with tirzepatide)

Insurance coverage evolving: - 30-40% of large employer commercial plans cover GLP-1 for obesity in 2026 (up from 5% in 2022) - Most plans require BMI 35+ with comorbidity or BMI 40+ alone - Some plans require failure of less-aggressive interventions first - Most plans require ongoing engagement with comprehensive lifestyle program

By 2028, expect competitive pressure from retatrutide + CagriSema to drive prices down 20-30% for current tirzepatide and semaglutide options.

When Each Medication Fits

**Tirzepatide (Zepbound) now**: Best current option for patients with BMI 30+ who want maximum-effectiveness FDA-approved obesity medication. Stronger evidence base, established safety profile, available through LillyDirect for cash-pay patients at $549-$1,059/month.

**Wait for retatrutide**: Patients with BMI 40+ seeking maximum non-surgical weight loss who can tolerate waiting 18-24 months for expected 2027 FDA approval. Retatrutide may approach bariatric surgery effectiveness, making it the best-available pharmacologic option.

**Wait for CagriSema**: Patients who responded well to semaglutide previously - CagriSema enhances semaglutide with cagrilintide for additional 8-10 percentage points of weight loss. Patients with established semaglutide tolerance may prefer continuing with this family of medications.

**Semaglutide (Wegovy) for cost reasons**: Patients who cannot afford tirzepatide but have insurance coverage for Wegovy. Wegovy is more commonly covered in early stages of insurance GLP-1 inclusion.

**Compounded GLP-1 (where legal)**: Limited availability post-shortage delisting. May provide cost-savings but quality and legal status concerns documented in detail in our compounded semaglutide guide.

For most patients seeking maximum weight loss in 2026 with current available options, tirzepatide is the right answer. Reconsider in 12-18 months when retatrutide approval becomes likely.

Bottom Line

For US patients seeking weight loss medication in 2026, tirzepatide (Zepbound) is the best-available option with established FDA approval, 21% average weight loss, and accessible pricing via LillyDirect at $549-$1,059/month. Patients with BMI 40+ should consider whether to wait 18-24 months for retatrutide (expected 2027) which may approach bariatric surgery effectiveness at 24%+ weight loss. CagriSema is Novo Nordisk's competitive response and will reach market simultaneously with retatrutide. By 2028, expect 3-4 highly effective GLP-1 options with price competition driving costs down 20-30% from 2026 levels. For now, start with tirzepatide and reassess in 18 months.

Sources

1. Jastreboff AM et al. Tirzepatide Once Weekly for Treatment of Obesity (SURMOUNT-1). NEJM, 2022. (Tirzepatide trial data)
2. Jastreboff AM et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity (Phase 2). NEJM, 2023. (Retatrutide phase 2 data)
3. Garvey WT et al. CagriSema for Obesity (REDEFINE-1). Manuscripts in publication 2025-2026. (CagriSema trial data)