What it is
Retatrutide (LY3437943) is a synthetic single-chain peptide that activates three receptors at once: GLP-1, GIP, and glucagon. It was developed by Eli Lilly and is described in the literature as a triple hormone-receptor agonist. It appears in obesity, type 2 diabetes, and fatty liver research, and has reached randomised Phase 2 trials.
How it works
It binds the GLP-1, GIP, and glucagon receptors, with the incretin arms studied for appetite and glucose signalling. The glucagon receptor component is thought to add energy expenditure and hepatic fat mobilisation, though the relative contribution of each arm is not established.
Regulatory status
- Cosmetic ingredient
- Research compound
- In clinical trials
- Approved medicine
In human clinical trials and not yet approved by the FDA or the EMA. Results to date are from trial populations under medical supervision.
What published research is studying
- Weight reduction in adults with obesity or overweight (Phase 2)
- Glycaemic control and body weight in adults with type 2 diabetes (Phase 2)
- Liver fat in metabolic dysfunction-associated steatotic liver disease (Phase 2a substudy)
- Gastrointestinal tolerability across escalating trial arms
Key findings
In a 48-week Phase 2 trial in 338 adults with obesity, the 12 mg group showed a mean weight reduction of 24.2%.
Jastreboff AM et al., N Engl J Med 2023In a 36-week Phase 2 trial in 281 adults with type 2 diabetes, HbA1c fell 2.02% at 24 weeks in the 12 mg group, against 0.01% with placebo.
Rosenstock J et al., Lancet 2023In a Phase 2a substudy of 98 participants with liver fat of at least 10%, mean liver fat fell 82.4% at 24 weeks in the 12 mg group.
Sanyal AJ et al., Nat Med 2024
What the studies measured
Study durations
- Phase 2 obesity trial: 48 weeks (NCT04881760).
- Phase 2 type 2 diabetes trial: 36 weeks, with the primary glycaemic readout at 24 weeks (NCT04867785).
- Liver fat substudy readout: 24 weeks within the 48-week obesity trial.
Endpoints
- Percent change in body weight
- Proportion reaching 5%, 10%, or 15% weight reduction
- Change in HbA1c from baseline
- Liver fat content by MRI
- Gastrointestinal adverse events and discontinuation
How strong is the evidence?
Human evidence is at the Phase 2 stage: randomised and placebo-controlled, but without published Phase 3 or long-term outcome results.
Common questions
Is Retatrutide an approved medicine?
In clinical trials. In human clinical trials and not yet approved by the FDA or the EMA. Results to date are from trial populations under medical supervision.
How much human research is there on Retatrutide?
Human evidence is at the Phase 2 stage: randomised and placebo-controlled, but without published Phase 3 or long-term outcome results.
Does UU supply Retatrutide?
Yes, as premium-grade research material for laboratory use. Every batch is tested by an independent lab and the certificate of analysis is published.