Maridebart Cafraglutide Reference

Plain English

What it is

Maridebart cafraglutide (brand name MariTide, formerly called AMG 133) is an experimental obesity medicine being developed by the drugmaker Amgen. It is an antibody-peptide conjugate, which is a lab-built molecule that does two things at once: it turns on the GLP-1 hormone pathway (which curbs appetite) and it blocks the GIP hormone pathway (which is tied to fat storage and insulin signals). It is given as a shot under the skin, and its design aims for a monthly shot rather than a weekly one.

What people use it for

It is being studied for weight loss in adults with obesity, including some who also have type 2 diabetes. Because it is still experimental, it is not approved and is not legally available outside of clinical trials. Anything sold online that claims to be this drug is not the real trial medicine and carries no maker quality guarantee.

What the science shows

A mid-stage (Phase 2) trial published in a major medical journal found it led to meaningful weight loss compared with a placebo (a dummy shot). Stomach and gut side effects such as nausea were common in that trial. Larger, final-stage (Phase 3) trials are still running, with main results expected around 2027, so the long-term picture is not settled yet.

The catch

This drug has not been approved by the FDA, and the only legitimate way to get it is by joining an official trial. The strongest evidence so far is from a mid-stage study, and the big confirming trials have not finished. Products sold online as MariTide do not come from the maker and cannot be trusted to be the real thing or to be safe.

Reference summary

The Phase 1 first-in-human report (Veniant et al. 2024 Nature Metabolism) characterized single-dose pharmacokinetics, tolerability, and exploratory body-weight signals consistent with the monthly subcutaneous dosing rationale. The Phase 2 obesity readout via Amgen sponsor disclosure reported placebo-adjusted body-weight reductions over the trial period. The Phase 2 obesity trial was published in the New England Journal of Medicine in 2025 (Jastreboff et al., PMID 40549887), reporting substantial weight reduction versus placebo with common gastrointestinal adverse events. The Phase 3 MARITIME program (MARITIME-1 and MARITIME-2) is enrolling, with pivotal readouts expected in 2027.

Regulatory and posture

Categories

GLP-1, Fat Loss, Metabolic

Aliases

MariTide, AMG 133, Amgen GLP-1R agonist + GIPR antagonist, Monthly subcutaneous antibody-peptide conjugate

Evidence posture

human - Investigational. The monthly cadence and GIP-antagonist (rather than agonist) arm differentiate this compound from the approved weekly GLP-1 / GIP agonist class. The Phase 3 MARITIME program is underway but has not read out. Do not present as available, approved, or compoundable.

Regulatory status

Investigational. Amgen's maridebart cafraglutide (MariTide / AMG 133) is an antibody-peptide conjugate combining a GLP-1 receptor agonist arm with a GIP receptor antagonist arm. There is no FDA-approved drug label. Phase 1 first-in-human results were published in Nature Metabolism in 2024 (Veniant et al.); Amgen's Phase 2 obesity study read out via sponsor disclosure in 2024 / 2025, and the Phase 3 MARITIME program (MARITIME-1 in obesity, MARITIME-2 in type 2 diabetes plus obesity) is now underway with pivotal readouts expected in 2027. Maridebart cafraglutide is not on FDA's approved bulk-substances list for traditional 503A compounding.

Content review status

investigational verified

Related tools

• Tirzepatide dose calculator - Run tirzepatide-focused vial draw math.
• GLP-1 conversion calculator - Convert a GLP-1 mg dose to U-100 units and ml.
• GLP-1 ramp planner - Preview a linear educational dose-step table.
• Peptide half-life calculator - Estimate single-dose decay from cited half-life constants.
• PK simulator overview - Public overview of the Pro pharmacokinetic simulator.
• GLP-1 taper planner overview - Public overview of the Pro GLP-1 taper planner.