# MariTide (Maridebart Cafraglutide): Results, Dosing, Approval

Source: https://www.dietglp.com/blog/maritide/
Published: 2026-11-09
Keywords: maritide, maritide amgen, maritide dosing, maritide vs mounjaro, maritide vs tirzepatide, maritide nejm, maritide clinical trial results, maritide approval, maritide fda approval, maritide release date, maritide generic name, maritide phase 3, maritide side effects, what is maritide amgen, is maritide a pill

**TL;DR:** MariTide (maridebart cafraglutide, AMG 133) is Amgen's experimental obesity shot, given once a month or less often. In its Phase 2 trial published in NEJM, people without diabetes lost 12.3% to 16.2% of their weight at 52 weeks versus 2.5% on placebo (up to about 20% in people who stayed on the drug). It is not FDA approved and has no price yet; Phase 3 MARITIME trials are still running as of November 2026. Whatever shot you end up on, keeping muscle is the part you control, and [Sharpy](https://apps.apple.com/us/app/glp-diet-app-sharpy/id6762084138) gives you one protein target and one 20-minute workout a day.

What is MariTide, and is it worth waiting for? **MariTide is Amgen's experimental weight-loss shot, generic name maridebart cafraglutide (code AMG 133). It is designed to be taken once a month, and Amgen is testing doses as rare as every 8 weeks or every 3 months.** In its Phase 2 trial, people without diabetes lost up to 16.2% of their body weight in a year. It is not approved, and it has no price.

MariTide is back in the news because Amgen's third-quarter 2026 report (November 3) listed a long run of Phase 3 trials, and coverage on November 8 focused on the idea of "fewer shots": 4 to 12 a year instead of 52.

## What is MariTide? The basics

| Question | Answer |
|---|---|
| Full name | Maridebart cafraglutide (AMG 133) |
| Maker | Amgen |
| What it is | An antibody linked to two GLP-1 peptides |
| How it works | Turns on the GLP-1 receptor, blocks the GIP receptor |
| How it is taken | Shot under the skin, monthly or less often |
| Pill version? | No |
| FDA status (Nov 2026) | Not approved; in Phase 3 |
| Price | None. It is not for sale |

The odd part is the GIP piece. Zepbound and Mounjaro (tirzepatide) *turn on* the GIP receptor. MariTide *blocks* it. Both approaches led to weight loss in trials, and scientists are still debating why. The antibody is what lets the drug last so long in the body, which is how monthly dosing works.

## MariTide clinical trial results (Phase 2, NEJM)

The Phase 2 study enrolled 592 adults and ran 52 weeks. It was published in the *New England Journal of Medicine* in 2025 (Jastreboff and colleagues). There are two ways to count results. "Everyone who started" includes people who quit. "People who stayed on the drug" shows the effect when taken as planned.

| Group | Weight change, everyone who started | Weight change, people who stayed on drug | Placebo |
|---|---|---|---|
| Obesity, no diabetes | -12.3% to -16.2% | -16.3% to about -20% | -2.5% |
| Obesity with type 2 diabetes | -8.4% to -12.3% | -12.1% to -17% | -1.7% |

The best results came with the 420 mg monthly dose. In the diabetes group, A1C fell by up to 2.2 percentage points (Amgen figure). Amgen also said weight loss had not plateaued at week 52, which suggests longer trials may show more.

When the headline "20%" came out in November 2024, Amgen's stock fell. Investors had hoped for more, since Lilly's retatrutide reached higher numbers. For a patient, 12% to 16% in a year is still a large and meaningful loss. See our [retatrutide guide](/blog/retatrutide-guide/) for how that drug compares.

## MariTide dosing: why monthly matters

Weekly shots like Wegovy and Zepbound mean 52 injections a year. MariTide's Phase 2 tested fixed monthly doses of 140, 280 and 420 mg, an every-8-weeks arm, and arms that started low and stepped up. That step-up detail matters for side effects (more below).

Phase 3 is now testing even longer gaps. Per Amgen's Q3 2026 report:
- **MARITIME-SWITCH**: people moving from weekly semaglutide or tirzepatide to MariTide every 8 weeks or every 3 months.
- **MARITIME-1 extension**: keeping weight off with monthly, every-8-week or every-3-month doses.

These are trial doses, not instructions. No one should try to space out a weekly drug to mimic this; that decision belongs to your prescriber.

## MariTide side effects

In Phase 2, the side effects looked like the rest of the GLP-1 class:
- **Most common:** nausea, vomiting and constipation.
- **Timing:** Amgen said they were mostly mild, short-lived and tied to the first dose.
- **Step-up dosing helped:** Quitting because of stomach side effects happened in 12% to 27% of groups that started at full dose, but only about 8% of groups that stepped up (AJMC summary of NEJM data).
- **Gallbladder:** gallbladder events were more common on the drug than on placebo.
- **Overall:** 90% to 99% of people on MariTide had at least one side effect of any kind, versus 68% on placebo.

Amgen reported no link to bone mineral density changes in Phase 2.

## MariTide vs Mounjaro, Zepbound and Wegovy

No head-to-head trial exists against tirzepatide. Amgen has started MARITIME-T2D-3, which compares MariTide with semaglutide in people with type 2 diabetes. Until then, this table shows the separate trials side by side. Durations differ, so treat it as a rough guide only.

| | MariTide | Zepbound / Mounjaro | Wegovy |
|---|---|---|---|
| Generic | Maridebart cafraglutide | Tirzepatide | Semaglutide |
| Maker | Amgen | Eli Lilly | Novo Nordisk |
| GIP receptor | Blocks it | Turns it on | Not targeted |
| Shot schedule | Monthly or less (in trials) | Weekly | Weekly (pill also available) |
| Key trial | Phase 2, 52 weeks | SURMOUNT-1, 72 weeks | STEP 1, 68 weeks |
| Average loss (everyone who started) | Up to 16.2% | 20.9% (15 mg) | 14.9% |
| Status | Not approved | FDA approved | FDA approved |

For the approved options, read [semaglutide vs tirzepatide](/blog/semaglutide-vs-tirzepatide/). Another long-acting shot in development is [bofanglutide](/blog/bofanglutide/), a once-monthly GLP-1 from China.

## Bigger, slower doses still mean muscle risk

A monthly shot does not change one basic fact: fast weight loss takes some muscle with it unless you eat enough protein and lift something. Fewer injections may even make it easier to forget the daily habits. [Sharpy](https://apps.apple.com/us/app/glp-diet-app-sharpy/id6762084138) sets one daily protein target, gives you one 20-minute strength workout and tracks a Shape Score, so the weight you lose is mostly fat. Our [protein target guide](/blog/protein-target-on-glp1/) explains how much you likely need.

## When will MariTide be available?

There is no release date. Here is what is known in November 2026:
- MARITIME-1 (no diabetes) and MARITIME-2 (type 2 diabetes): ongoing.
- MARITIME-CV (heart outcomes), MARITIME-OSA-1 and OSA-2 (sleep apnea): enrollment complete.
- MARITIME-HF (heart failure): enrolling.
- Two more type 2 diabetes studies: due to start in Q4 2026.

An analyst quoted by TheStreet expects Phase 3 results in 2027. After that, an FDA review usually takes about a year. Anything sold online today as "MariTide" is not the approved drug and should be avoided.

## The bottom line

MariTide is a promising once-a-month shot that is still years from a pharmacy, with Phase 2 weight loss in the same range as today's weekly drugs. If you need treatment now, ask your prescriber about approved options. While you wait or while you start, protect your muscle with protein and strength work. [Sharpy](https://apps.apple.com/us/app/glp-diet-app-sharpy/id6762084138) makes that one simple daily routine.

## Sources

- [Amgen: Phase 2 MariTide 52-week results, Nov 26 2024](https://www.amgen.com/newsroom/press-releases/2024/11/amgen-announces-robust-weight-loss-with-maritide-in-people-living-with-obesity-or-overweight-at-52-weeks-in-a-phase-2-study)
- [Jastreboff et al., Once-Monthly Maridebart Cafraglutide for the Treatment of Obesity, NEJM 2025](https://www.nejm.org/doi/full/10.1056/NEJMoa2504214)
- [AJMC summary of the NEJM Phase 2 trial, Dec 2025](https://www.ajmc.com/view/once-monthly-maridebart-cafraglutide-shows-up-to-16-weight-loss)
- [Amgen third-quarter 2026 financial results, Nov 3 2026](https://prnewswire.com/news-releases/amgen-reports-third-quarter-2026-financial-results-302928131.html)
- [TheStreet via Yahoo Finance: Amgen's new drug could mean fewer shots, Nov 8 2026](https://finance.yahoo.com/healthcare/articles/amgens-drug-could-mean-fewer-224700612.html)
- [Jastreboff et al., SURMOUNT-1, NEJM 2022](https://www.nejm.org/doi/full/10.1056/NEJMoa2206038)
- [Wilding et al., STEP 1, NEJM 2021](https://www.nejm.org/doi/full/10.1056/NEJMoa2032183)


## Frequently asked questions

**Q: What is MariTide?**

A: MariTide is the nickname for maridebart cafraglutide (code AMG 133), an experimental obesity medicine from Amgen. It is an antibody joined to two GLP-1 peptides. It turns on the GLP-1 receptor and blocks the GIP receptor. It is given as a shot under the skin once a month or less often.

**Q: Is MariTide FDA approved?**

A: No. As of November 2026, MariTide is in Phase 3 trials (the MARITIME program) and has not been approved by the FDA or any other regulator. Amgen has not announced a filing date.

**Q: How much weight do you lose on MariTide?**

A: In the Phase 2 trial (Jastreboff et al., NEJM 2025), adults with obesity and no diabetes lost 12.3% to 16.2% of body weight at 52 weeks versus 2.5% on placebo, counting everyone who started. Among people who stayed on treatment, loss reached up to about 20%. People with type 2 diabetes lost 8.4% to 12.3% versus 1.7% on placebo.

**Q: What are the side effects of MariTide?**

A: In Phase 2, the most common side effects were nausea, vomiting and constipation. Amgen said they were mostly mild, short-lived and tied to the first dose, and much less common when the dose was raised step by step. Gallbladder events happened more often on the drug than on placebo.

**Q: Is MariTide a pill?**

A: No. MariTide is an injection. Amgen says it expects to deliver it as a single dose in a handheld autoinjector. If you want a GLP-1 pill, the approved options in the US are the Wegovy pill and Foundayo.

**Q: When will MariTide be available?**

A: There is no release date. Phase 3 trials are ongoing, and an analyst quoted by TheStreet in November 2026 expects Phase 3 results in 2027. After results, Amgen would still need to file with the FDA and wait for a decision.

**Q: MariTide vs Mounjaro: which works better?**

A: Nobody knows yet, because they have never been tested against each other. Tirzepatide (Mounjaro, Zepbound) produced about 20.9% loss at 72 weeks in SURMOUNT-1. MariTide produced up to 16.2% at 52 weeks in Phase 2, counting everyone. Different trial lengths and designs make a direct comparison unreliable.