MariTide by the Numbers
What Exactly Is MariTide?
A monthly injection that works completely differently from Zepbound and Wegovy. MariTide is the only weight loss drug in development that blocks the GIP receptor rather than activating it, and it's also the only monthly injection heading toward FDA approval.
Every GLP-1 drug approved today works by activating hormone receptors to reduce appetite. MariTide takes a different path: it's a bispecific antibody peptide conjugate that simultaneously blocks the GIP receptor (antagonist) while activating the GLP-1 receptor (agonist).
This is the opposite approach to Zepbound (tirzepatide), which activates both GIP and GLP-1. Yet both produce strong weight loss results, suggesting GIP may play a complex and still not fully understood role in obesity. Because MariTide is a large antibody molecule rather than a small peptide, it stays active in the body far longer, which is why it only needs to be injected once per month.
Block One, Activate One
MariTide blocks GIP and activates GLP-1, the opposite of what Zepbound does. This dual action approach produces powerful appetite suppression through a mechanism no other approved drug uses.
One Shot Per Month
As a large antibody peptide conjugate, MariTide stays active in the body for weeks, enabling a once monthly dosing schedule. For many patients this is a major practical advantage over weekly injections like Wegovy or Zepbound.
Appetite Suppression Kicks In
GLP-1 receptor activation reduces hunger and food cravings. Phase 2 participants reported significantly less interest in food, smaller comfortable portion sizes, and reduced "food noise" within the first few weeks of treatment.
Weight Loss Continues, No Plateau
A standout finding: unlike most drugs that plateau after 6-12 months, MariTide patients were still actively losing weight at 52 weeks with no sign of leveling off. Phase 3 will test whether this continues even longer.
What the Trials Showed
Full Phase 2 data (ADA 2025): up to ~20% non diabetic, up to ~17% with Type 2 diabetes, no plateau at 52 weeks. Full Phase 2 results were presented at the American Diabetes Association Scientific Sessions in June 2025. Amgen tested MariTide in two populations: adults with obesity (no diabetes) and adults with obesity and Type 2 diabetes. Both showed meaningful weight loss with no plateau at the 52-week endpoint.
Most weight loss drugs produce a curve that flattens out, patients lose weight for 6-12 months then level off even while continuing the drug. MariTide's Phase 2 data showed participants were still losing weight at the 52-week endpoint with no sign of leveling off. This means total long term weight loss could be substantially higher than the ~20% measured. Phase 3's longer follow up will quantify this.
Where Things Stand
Phase 3 MARITIME is underway. FDA decision expected 2028+. MariTide has cleared Phase 1 and 2 and is now in the largest phase of testing. The full roadmap below.
MARITIME Phase 3 trials are actively enrolling. You receive MariTide at no cost with close medical supervision throughout the study.
Search Open Trials →"A meaningful chunk of my patients have tried GLP-1s and lost some weight but not enough. Maritide is specifically being developed for that population. I don't see many drugs targeting that gap and it's a gap that genuinely exists."
Dr. Humberto Fernandez Miro, MD
Family Medicine · Clinical Research
Is MariTide Right for You?
Not available yet. Here's who it looks best suited for when it is. MariTide isn't approved yet. Based on Phase 2 data and the ongoing Phase 3 program, here's who this drug looks most promising for, and who should think carefully before waiting for it.
✅ Likely Good Candidates
- Adults with BMI 30+ who value a once monthly dosing schedule over weekly
- People who plateau on weekly GLP-1 drugs, MariTide's different mechanism may restart progress
- Patients with obesity and Type 2 diabetes seeking an alternative mechanism
- Anyone interested in the longest term potential, weight loss hadn't plateaued by trial end, which suggests higher totals are possible with longer treatment
- People willing to wait until 2028+ for a potentially distinct and convenient option
⚠️ Things to Consider
- Not FDA approved, still 2+ years away at minimum
- Phase 2 weight loss (~20%) is lower than retatrutide (28.7% Phase 3) or CT-388 (22.5%) in terms of peak numbers
- Diabetic patients saw lower weight loss (12.3%), typical for GLP-1 class drugs in T2D populations
- As an antibody based drug, manufacturing and cost structure may differ from small molecule GLP-1s
- People who need treatment now should not wait, currently approved drugs (Wegovy, Zepbound) are proven options
How MariTide Stacks Up
MariTide vs. current and upcoming weight loss drugs. MariTide occupies a unique space, monthly dosing, GIP blocking mechanism, and a still climbing weight loss curve with no observed plateau.
| Drug | Mechanism | Best Weight Loss | Dosing | Status |
|---|---|---|---|---|
| 💉MariTide | GIP Antagonist + GLP-1 Agonist | ~20%* (no plateau) | Monthly | Phase 3 |
| 💉Wegovy | GLP-1 Agonist | 15% | Weekly | FDA Approved |
| 💉Zepbound | GLP-1 + GIP Agonist | 20-21% | Weekly | FDA Approved |
| 💉Retatrutide | GLP-1 + GIP + Glucagon | 28.7% (Ph3) | Weekly | Phase 3 |
*MariTide's weight loss curve was still declining at 52 weeks, final long term totals expected to be higher. All figures from Phase 2/3 trial publications.
MariTide FAQ