MariTide (maridebart cafraglutide) is an investigational, once-monthly injectable bispecific molecule from Amgen that combines a GIP receptor antagonist antibody with two GLP-1 receptor agonist peptides. A Phase 2 trial reported up to 20% weight loss at 52 weeks. It is not currently FDA approved.

What is the recommended dose of MariTide?

The typical research dose of MariTide is 140-420 mg once monthly (Phase 2 fixed-dose and escalation arms), administered Once monthly (or every 8 weeks at the highest dose arm tested) via Subcutaneous injection. Use the ASCEND calculator for exact syringe draw volumes based on your vial size.

How is MariTide administered?

MariTide is typically administered Subcutaneous injection, Once monthly (or every 8 weeks at the highest dose arm tested), in research cycles of Phase 2 trial duration 52 weeks (Part 1), extension ongoing. Approximate half-life: ~21 days (reported ~3x longer than semaglutide).

What is the research status of MariTide?

MariTide is at the Phase 3 (MARITIME program) stage of research. FDA status: Not approved. WADA status: Not listed.

MariTide: Mechanism, Dosing & Research Data

Storage Stability

Lyophilized

~1 year

Reconstituted

~30 days (2-8°C)

Room temp

Avoid

Mechanism of Action

Bispecific GIPR Antagonism + GLP-1R Agonism

MariTide pairs a monoclonal antibody that antagonizes (blocks) the GIP receptor with two GLP-1 receptor agonist peptides conjugated to that same antibody. This is mechanistically the opposite of tirzepatide's GIP receptor agonism, but Amgen's data suggests chronic GIP receptor antagonism combined with GLP-1 agonism also produces substantial weight loss, through a pathway still being characterized. The antibody component gives the molecule a long half-life (~21 days), enabling once-monthly dosing.

Research Summary

Phase 2 (NCT05669599)

Phase 2 Complete

Two cohorts: 465 adults with obesity/overweight without type 2 diabetes, and 127 adults with obesity/overweight and type 2 diabetes, 52 weeks (Part 1), once-monthly subcutaneous. Fixed-dose arms of 140 mg, 280 mg, and 420 mg, plus 4-week and 12-week escalation arms to a 420 mg target, and a 420 mg every-8-week arm. Non-diabetic cohort: up to ~20% mean weight loss. Diabetic cohort: up to ~17% mean weight loss. No weight-loss plateau observed at 52 weeks. Published in The New England Journal of Medicine (2025).

Phase 3 (MARITIME program)

Active Research

Amgen's Phase 3 MARITIME program is enrolling multiple trials in obesity, type 2 diabetes, and related conditions including elevated liver fat, heart disease, and sleep apnea.

Research Protocols

Goal	Dose	Frequency	Route
Phase 2 fixed-dose reference	140 mg, 280 mg, or 420 mg once monthly	Monthly	Subcutaneous
Phase 2 escalation reference	4-week or 12-week escalation to a 420 mg target	Monthly	Subcutaneous

Not yet approved, and not a calculator candidate: MariTide is manufactured as a monoclonal antibody-peptide conjugate, not a lyophilized peptide powder sold in a vial. There is no realistic "reconstitute with BAC water" product format for a biologic like this, unlike every other entry on this site, it is included here for research reference only.

Interactions

Safety Profile

The most common side effects reported were gastrointestinal: nausea, vomiting, and constipation, reduced with dose escalation. No long-term human safety data exists yet; MariTide remains in Phase 3 trials.

References

[1]Once-Monthly Maridebart Cafraglutide for the Treatment of Obesity, A Phase 2 Trial. N Engl J Med. 2025.

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Categories: Weight Management Metabolic Phase 3 GIP Agonist GLP-1 Agonist Antibody Conjugate

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5-Amino-1MQ Adipotide Adropin AgRP AICAR Amycretin Amylin Angiotensin (1-7)

Verified Scientific Data Last audited: October 5, 2026

Data Sources & External References

⬡ PubMed / NCBI, Research Literature ⬡ NCBI, Full-Text Articles ⬡ PubChem, Chemical Database

Source: peer-reviewed literature · Domain: ascendpeptide.org

Evidence	B+ · Phase 3
Mol. weight	Not publicly disclosed (monoclonal antibody conjugate, substantially larger than a typical peptide)
Half-life	~21 days (reported ~3x longer than semaglutide)
Peak time	Unknown
Route(s)	Subcutaneous injection
Typical dose	140-420 mg once monthly (Phase 2 fixed-dose and escalation arms)
Frequency	Once monthly (or every 8 weeks at the highest dose arm tested)
Cycle	Phase 2 trial duration 52 weeks (Part 1), extension ongoing
Storage	Unknown for human dosing
WADA	Not listed Not on WADA Prohibited List as of 2026; investigational, not commercially available
FDA	Not approved Investigational (Amgen). Phase 2 results published in The New England Journal of Medicine (2025). Phase 3 MARITIME program underway.
Research	Phase 3 (MARITIME program)

MariTide