Mazdutide and Retatrutide are supplied strictly as laboratory research materials. They are not approved, intended or authorised for human consumption or any therapeutic use in this context. This article is written for qualified researchers and is not medical advice.
Two paths to the glucagon arm
The last few years of incretin research have been an exercise in adding receptors. Mazdutide and Retatrutide both sit beyond the single-target GLP-1 benchmark, and both incorporate a glucagon-receptor arm that is studied for raising energy expenditure and mobilising hepatic lipid. Where they part ways is the rest of the receptor set: Mazdutide pairs glucagon with GLP-1 and stops there, while Retatrutide adds a third target — the GIP receptor — to become the only triple agonist of the two. If you want the mechanistic background on what each receptor does, our explainer on GLP-1 vs GIP vs glucagon agonists unpacks it; here we put the two molecules directly against each other. It is essentially a question of dual versus triple.
| Mazdutide | Retatrutide | |
|---|---|---|
| Class / peptide type | Dual agonist · oxyntomodulin analogue | Triple agonist · "GGG" tri-agonist |
| Receptor targets | GLP-1 + glucagon | GIP + GLP-1 + glucagon |
| Structure / MW note | Fatty-acid-conjugated long-acting peptide | 39-aa peptide, C20 fatty-acid tail, ~4,731 Da |
| Half-life / duration | Long-acting; once-weekly | ~6 days; once-weekly |
| Main research focus | Weight management, liver fat, T2D (GLORY / DREAMS) | Weight management, T2D, MASLD (TRIUMPH) |
| Developer | Innovent / Eli Lilly (IBI362 · LY3305677) | Eli Lilly (LY3437943) |
| Regulatory status | Investigational · first NDA under NMPA (China) review | Investigational · Phase 3 |
Mazdutide: the GLP-1/glucagon dual agonist
Mazdutide (developer codes IBI362 and LY3305677) is a synthetic, fatty-acid-conjugated long-acting peptide advanced by Innovent under licence from Eli Lilly. It is built on the scaffold of oxyntomodulin — a naturally occurring gut hormone that engages the GLP-1 and glucagon receptors together — and engineered for a once-weekly duration of action. The GLP-1 arm reduces energy intake through appetite suppression, slowed gastric emptying and glucose-dependent insulin secretion, while the glucagon arm is studied for increasing energy expenditure and shifting hepatic lipid. That combination has drawn particular attention to its liver-fat effects.
In the Phase 3 GLORY-1 trial in Chinese adults with overweight or obesity, Mazdutide produced roughly 14.3% mean body-weight reduction at 48 weeks at its higher doses, with a notably large proportion of participants achieving substantial liver-fat reductions. It has also been studied in type 2 diabetes through the DREAMS programme. On the strength of the GLORY data, Innovent submitted Mazdutide's first NDA for chronic weight management to China's NMPA — so it is further along the regulatory path in one jurisdiction than most of the class, though it remains investigational everywhere else. Its full profile lives on our Mazdutide knowledgebase page, and research-grade material is available to buy Mazdutide UK.
Retatrutide: the GIP/GLP-1/glucagon triple agonist
Retatrutide (Eli Lilly, code LY3437943) takes the same glucagon arm and builds a broader molecule around it. It is a synthetic 39-amino-acid peptide with a C20 fatty-acid tail (~4,731 Da) engineered to activate three receptors at once: GIP, GLP-1 and glucagon. That extra GIP arm is the whole difference between the two compounds — it contributes complementary insulinotropic and adipose-tissue activity that a GLP-1/glucagon dual agonist simply does not have. The result is the first-in-class "GGG" triple agonist, and the most metabolically active compound in the incretin class studied to date.
The data reflect that reach. In the Phase 2 TRIUMPH-1 obesity trial, Retatrutide reached approximately 24.2% mean body-weight reduction at 48 weeks at the top dose — the largest figure reported for any incretin-class compound — and, notably, the curve had not plateaued at study end. A Phase 2a MASLD study saw liver fat fall by roughly 82% at the higher doses. Retatrutide carries a ~6-day half-life and is now in Phase 3 development, but it remains investigational and is supplied only as a research reagent. See the Retatrutide knowledgebase page for the complete profile, or buy Retatrutide UK for research-grade material.
What the differences mean in a research context
Read the two profiles side by side and the structural story is clean: both add glucagon to the incretin mix, but Retatrutide adds GIP on top. That single extra receptor is the difference between a dual and a triple agonist, and it tracks with the difference in reported effect size — Mazdutide's ~14.3% in Phase 3 against Retatrutide's ~24.2% in Phase 2. For the same reason, both compounds show a pronounced liver-fat signal: the shared glucagon arm is the one most associated with hepatic lipid mobilisation, which is why each has attracted MASLD/liver-fat research alongside weight management.
But the headline percentages carry the usual caveat researchers should hold onto. GLORY-1 and TRIUMPH-1 were different trials — different populations, durations and protocols — and were never designed to be compared head-to-head, so the numbers describe a trend rather than a controlled ranking. There is also an asymmetry in maturity: Mazdutide's first NDA is already under NMPA review, giving it a late-stage regulatory footing in one market, whereas Retatrutide's larger effect comes from Phase 2 data and its profile is still being written in ongoing Phase 3 work. In short, one is the further-progressed dual agonist, the other the higher-ceiling triple. For where the triple sits against the rest of the field, our Semaglutide vs Tirzepatide vs Retatrutide piece maps the whole incretin ladder.
For research purposes the pair is best understood as a controlled contrast in receptor count: hold the glucagon arm constant, add or remove GIP, and watch what changes downstream. That is precisely why dual and triple agonists are studied alongside one another rather than in isolation.
The bottom line
Mazdutide and Retatrutide both bring glucagon into play, but Mazdutide is a two-receptor dual agonist while Retatrutide is a three-receptor triple — and that extra GIP arm is what separates their mechanisms and their trial numbers. Mazdutide is the more regulatorily advanced of the two; Retatrutide posted the larger effect. For research-grade material, see our dedicated pages to buy Mazdutide UK and buy Retatrutide UK, each ≥99% purity with a COA.