How Does Retatrutide Compare With Tirzepatide?

Retatrutide showed higher average weight loss in its trials than tirzepatide showed in its own, and researchers think the extra glucagon action helps explain the gap. The two drugs were tested in separate studies with different people and timelines. Tirzepatide is FDA approved and available by prescription now while retatrutide remains trial only.

How do they work differently?

Tirzepatide copies two gut hormones, GIP and GLP-1. They slow digestion and tell your brain you feel full, so you eat less and your blood sugar stays steadier. Retatrutide copies those same two hormones and adds glucagon, a hormone that prompts your body to release and burn stored fat. The idea is appetite control plus higher energy use (GoodRx comparison).

How much weight have people lost on each?

On the highest studied doses, people taking 12 mg retatrutide lost up to 28.7% of body weight on average at 68 weeks. People taking 15 mg tirzepatide lost up to 20.9% on average at 72 weeks in SURMOUNT-1 (Ro comparison). Researchers ran these as separate trials, so the gap does not show what would happen for the same person choosing between them.

Which one can you get today?

You can get tirzepatide now as Zepbound or Mounjaro with a prescription filled at a licensed pharmacy (Drugs.com comparison). Retatrutide is available only in clinical trials, with approval estimates pointing to late 2026 to 2027 (Midi explainer). Any website offering to ship retatrutide now is not a safe source. If you want weight loss support now, you can check whether a tirzepatide plan fits through /quiz.