Retatrutide vs MariTide: Two Next-Generation Shots Compared

Retatrutide and MariTide are two of the most closely watched weight-loss drugs still in development, and they differ in both power and convenience. Retatrutide, a weekly injection, has produced some of the largest weight loss numbers ever recorded in trials (around 24% or more), while MariTide stands out for once-monthly dosing with roughly 20% weight loss and no plateau in early data. Both are investigational, meaning neither is FDA-approved or available to prescribe. Here’s how they stack up and what you can actually use today.

Different Engines Under the Hood

These two drugs chase weight loss through different hormone combinations. Retatrutide is a triple agonist, activating three receptors at once: GLP-1, GIP, and glucagon. That third target, glucagon, appears to boost energy expenditure on top of appetite suppression, which may explain its unusually high results.

MariTide takes a different route. It activates the GLP-1 receptor while blocking the GIP receptor, and it’s built as a long-acting antibody conjugate that stays in the body for weeks. That design is what allows once-monthly dosing, roughly a dozen injections a year instead of about 52.

How They Compare on Results

Retatrutide’s numbers have driven much of its attention. In its phase 2 trial published in the New England Journal of Medicine in 2023, retatrutide produced up to about 24% average weight loss at 48 weeks, and later phase 3 readouts have pointed to similar or higher figures. MariTide’s phase 2 data showed up to roughly 20% weight loss at 52 weeks, with the notable feature that weight loss had not plateaued by the end of the study.

Where Each One Stands

Retatrutide is further along. Its phase 3 program is well underway, with a regulatory submission expected around the end of 2026, which could put approval sometime after that. MariTide’s phase 3 MARITIME program is still enrolling, with major readouts expected in 2027, so it sits a step or two behind on the timeline.

The trade-off between them is efficacy versus convenience. Retatrutide currently shows larger weight loss but requires a weekly shot. MariTide offers the ease of a monthly injection at somewhat lower (though still substantial) weight loss. Which matters more would come down to personal preference, but that’s a decision for the future, since neither can be prescribed today.

Consider a hypothetical patient tracking these drugs while deciding whether to wait. Because both are investigational and years from routine availability, waiting means going untreated in the meantime. The practical move for most people is to start an effective, available option now rather than hold out for a launch that may be a long way off. TrimRx prescribes injectable semaglutide and tirzepatide, in compounded and brand-name forms, which produce meaningful weight loss today, and you can explore what fits you through the TrimRx quiz.

Frequently Asked Questions

Is retatrutide or MariTide better?

In trials, retatrutide has produced larger weight loss (around 24% or more versus roughly 20% for MariTide), but MariTide offers once-monthly dosing instead of weekly. Both are investigational, so neither is available to compare in real-world use yet.

When will retatrutide or MariTide be available?

Retatrutide is further along, with an FDA submission expected around the end of 2026, while MariTide’s phase 3 readouts are expected in 2027. Actual availability would follow later, assuming the trials succeed and the FDA approves them.

Can I get either drug now?

No. Both retatrutide and MariTide are investigational and not FDA-approved. For an effective option you can start today, injectable semaglutide and tirzepatide are available through providers like TrimRx.

To explore the weight-loss options available to you now, you can take the TrimRx quiz for a licensed provider’s review.

This article is for educational purposes and is not medical advice. Retatrutide and MariTide are investigational and not FDA-approved or available for prescription. Trial figures are preliminary and may change. Consult a qualified healthcare provider. Individual results vary.