MariTide vs Tirzepatide
A monthly GIP-antagonist vs the weekly GIP-agonist
MariTide (Amgen’s AMG133) is unusual twice over: it blocks the GIP receptor instead of activating it, and it is dosed as infrequently as once a month. Tirzepatide (Mounjaro/Zepbound) activates GIP and is dosed weekly. Here is how the two opposite GIP strategies compare.
The GIP paradox — and a monthly dose
Here is the twist that makes this comparison interesting: tirzepatide is a GLP-1/GIP dual agonist (it activates GIP), while MariTide is a GLP-1 agonist combined with a GIP antagonist (it blocks GIP). Both approaches have produced strong weight loss in trials, which is part of why GIP biology is so debated.
The other big difference is convenience: MariTide is a peptide-antibody conjugate designed for very infrequent dosing — as little as once monthly or less — versus tirzepatide’s weekly injection. MariTide reported roughly 20% weight loss in its Phase 2 program; tirzepatide reported about 22.5% in SURMOUNT-1.
Tirzepatide is approved and available; MariTide is investigational. Cross-trial numbers are not directly comparable.
MariTide vs Tirzepatide at a glance
- ⚡Mechanism: GLP-1 agonist + GIP receptor ANTAGONIST
- ⚡Dosing: designed for monthly (or less frequent) injection
- ⚡Phase 2: about 20% mean weight loss
- ⚡Peptide-antibody conjugate for a long duration of action
- ⚡Status: investigational — not FDA approved
- ✓Mechanism: GLP-1 + GIP dual AGONIST (activates GIP)
- ✓Dosing: once-weekly subcutaneous pen
- ✓SURMOUNT-1: about 22.5% mean weight loss at 72 weeks
- ✓FDA approved for obesity and type 2 diabetes
- ✓Years of real-world safety and efficacy data
Which appeals to you?
If you want proven, approved weight loss now, tirzepatide is the option you can start — weekly dosing, extensive data. MariTide’s headline appeal is convenience: a monthly (or less frequent) shot would be a meaningful lifestyle difference for many, and its opposite GIP strategy is scientifically intriguing.
MariTide cannot be prescribed yet and its data is earlier, so it is a "watch closely" candidate rather than an option available today. Tolerability at monthly dosing is one of the things later trials are characterizing.
Track now, compare later
There is no head-to-head trial of MariTide and tirzepatide, so the figures come from separate studies. Logging your own response in Shotlee — weight, appetite, side effects, and labs — gives you an objective baseline so a future switch is evidence-based.
Use this comparison as a framework and confirm specifics with your healthcare provider.
MariTide vs Tirzepatide: Frequently Asked Questions
Not proven — there is no head-to-head trial. Tirzepatide has deeper, approved data (about 22.5%) and is available now; MariTide’s draw is monthly dosing and its novel GIP-antagonist mechanism, at about 20% in Phase 2. MariTide is investigational.
This is the "GIP paradox" — both activating and blocking the GIP receptor (alongside GLP-1) have produced weight loss in trials. The biology is still debated, and MariTide and tirzepatide represent the two opposite strategies.
MariTide (AMG133) is designed for infrequent dosing — as little as once a month or less — versus tirzepatide’s weekly injection. That convenience is a key reason it is closely watched.
No. MariTide (Amgen’s AMG133) is investigational and in clinical trials for obesity. Tirzepatide is approved and available.
Yes. Shotlee logs doses, weight, side effects, and labs for your current protocol, free — and handles weekly or monthly dosing schedules.
Track Your Protocol in Shotlee
Free dose logging, weight trends, and side effect tracking — weekly or monthly.
