Retatrutide vs Mazdutide
Verdict: On raw effect size retatrutide leads: ~24% weight loss at 48 weeks in phase 2 versus ~15% for mazdutide at 6 mg in GLORY-1. But mazdutide is the only one of the two that is actually approved anywhere (China, 2025), which means real-world pharmacovigilance data exist for it and not for retatrutide. If the question is 'which is stronger', retatrutide; if it is 'which has cleared a regulator', mazdutide — and the 9 mg mazdutide dose now in trials may narrow the gap.
Side by side
| Retatrutide | Mazdutide | |
|---|---|---|
| Typical dose | 1 mg–12 mg | 3 mg–9 mg |
| Frequency | 1x weekly, titrated up | 1x weekly, titrated up |
| Administration | subcutaneous injection | subcutaneous injection |
| Common vials | 5 mg, 10 mg, 20 mg, 30 mg | 5 mg, 10 mg |
| Typical mix | 10 mg + 2 ml water | 10 mg + 2 ml water |
| Units for typical dose | 40 units (2 mg) | 80 units (4 mg) |
Three receptors vs two
Both add glucagon agonism to GLP-1 — glucagon raises energy expenditure and pulls fat out of the liver, which is why both show unusually strong liver-fat results. Retatrutide layers GIP on top, the same receptor that gives tirzepatide its edge over semaglutide. Mechanistically, retatrutide is tirzepatide plus glucagon; mazdutide is semaglutide plus glucagon.
Dosing scales are not interchangeable
Retatrutide's phase 2 arms ran 1 to 12 mg weekly; mazdutide's approved range is 3 to 6 mg with 9 mg under study. The milligram numbers overlap but the potencies do not — 6 mg of one is not 6 mg of the other. Both are titrated slowly because the glucagon component amplifies nausea when steps are rushed.
What the trials actually showed
Retatrutide phase 2 (obesity, 48 weeks): 17.5% at 4 mg, 22.8% at 8 mg, 24.2% at 12 mg, curves still falling at the end. Mazdutide GLORY-1 (48 weeks): ~12% at 4 mg and ~15% at 6 mg, with meaningful drops in liver fat and uric acid. Mazdutide's numbers sit close to semaglutide's; retatrutide's sit above tirzepatide's.
Can you stack them?
Neither is combined with other GLP-1-class drugs in any protocol — they already occupy the same receptors. Discussion of stacking with either centers on protein intake and resistance training to protect lean mass during rapid weight loss.
More comparisons
Educational comparison based on commonly published research protocols — not medical advice or an endorsement of any compound.