Retatrutide might be the most effective weight loss medication we've seen yet. In clinical trials, people lost up to 28.7% of their body weight after 68 weeks. That's significantly more than typically seen with current treatments like Wegovy or Mounjaro.
But here's the catch: retatrutide isn't approved yet. It's still undergoing clinical trials, which means we don't know exactly what doses it'll be available in once it reaches the market, or what the official dosing schedule will be.
That said, clinical research gives us a fairly clear picture of how retatrutide dosing works. Here's everything we know so far.
Key takeaways
- Retatrutide isn't approved yet and isn't expected to launch in the UK until at least mid-2026
- In clinical trials, target doses ranged from 0.5mg to 12mg weekly, with the most common being 4mg, 8mg, 9mg and 12mg
- Different dosing schedules were tested, with most people starting at 2mg and escalating every 4 weeks
- The 12mg dose produced the most weight loss (up to 28.7% after 68 weeks)
- Starting at 2mg rather than 4mg helped reduce side effects during escalation
What is retatrutide?
Retatrutide is an investigational weight loss injection given once weekly. Like Wegovy and Mounjaro, it works by making you feel fuller for longer, so you naturally eat less.
What makes retatrutide different is how it works. Wegovy mimics a single hunger hormone called GLP-1, whilst Mounjaro mimics two hormones: GLP-1 and GIP. Retatrutide takes this a step further by activating three hormones: GLP-1, GIP, and glucagon.
This triple action appears to make it more potent than existing treatments, though we're yet to see head-to-head comparison studies.
FYI: Retatrutide is also being studied as a type 2 diabetes treatment, where it's shown impressive results for both blood sugar control and weight loss.
Want to know more? Check out our guide to retatrutide, tirzepatide, and semaglutide.
¹
