Mazdutide
Dual GLP-1 / glucagon receptor agonist
An experimental peptide based on a natural gut hormone. Researchers studied it mainly in phase 2 and phase 3 trials in China.
Retatrutide
Also cited in the literature as LY3437943
An experimental peptide that acts on three hormone receptors. Researchers studied it in phase 2 trials involving weight and blood sugar.
Regulatory status: Not licensed as a medicine in the United Kingdom. It holds no MHRA marketing authorisation, has no approved indication, and is not approved for human or animal use.
Hormone & signalling research
Research stage: Phase 2 results published; phase 3 trials under way
Cells
Animal studies
Human trials
The research pathway — not every compound has reached human trials. Illustrations are simplified, not study results.
What it is
Retatrutide is a laboratory-made peptide. Researchers also called it LY3437943 in published studies.
It copies some effects of hormones made in the gut. These hormones help the body control blood sugar and energy use.
How researchers think it works
Laboratory studies found that retatrutide activated three targets: GIP, GLP-1 and glucagon receptors. These receptors help regulate blood sugar, appetite and energy use.
Researchers suggested that its effect on the glucagon receptor may set it apart from peptides that act on only one or two targets. Trials also recorded changes in how the body used energy.
What has research seen in people?
In people, this is one of the better-studied newer peptides. Mid-stage trials in adults with obesity reported large average falls in body weight over 48 weeks compared with a placebo group.
A separate trial in adults with type 2 diabetes reported lower average blood sugar readings than placebo.
The most commonly reported downsides were stomach and bowel effects — nausea, diarrhoea and constipation — usually described as mild or moderate.
Those results came from supervised trials using pharmaceutical-grade material in selected participants. They say nothing about outcomes outside that setting, and no regulator has licensed it.
Where this material is listed
For laboratory research use only. Not a medicine and not for human or animal use.
Veritide does not sell or supply anything. This links to a third-party UK laboratory supplier; we may earn a commission if you buy through it, at no extra cost to you. Materials are sold for laboratory research use only and are not licensed medicines.
What studies have found
- A 2023 phase 2 trial published in the New England Journal of Medicine studied adults with obesity. Over 48 weeks, researchers reported greater weight loss in the study groups than in the placebo group.
- A separate phase 2 trial studied adults with type 2 diabetes. Researchers reported changes in HbA1c, a measure of average blood sugar, compared with placebo and another treatment.
- Across the published trials, nausea, diarrhoea and constipation were the most common side effects. Researchers described most of these events as mild or moderate.
- Phase 3 trials were under way at the time of writing. Their results had not yet appeared in peer-reviewed journals.
What we still do not know
- The published trials were fairly short phase 2 studies. They were not designed to show long-term health outcomes.
- The studies included carefully selected groups of people, so the findings may not apply to everyone.
- No regulator had approved retatrutide as a medicine at the time of writing.
Sources
Related profiles
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