Tirzepatide: The Dual GIP / GLP-1 Agonist
A dual incretin receptor agonist
Tirzepatide (development code LY3298176) is a dual receptor agonist, a single peptide that activates both the GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptors. It sits one step beyond single-incretin compounds like semaglutide, and one step short of the triple agonist retatrutide.
The two pathways
- GLP-1 receptor: an incretin target tied in research to glucose-dependent insulin signaling and satiety pathways, the same receptor semaglutide acts on alone.
- GIP receptor: a second incretin target. Combining it with GLP-1 in one molecule is what defines tirzepatide as a dual agonist.
Where it sits in the family
The research progression runs single-target (semaglutide to GLP-1) to dual (tirzepatide to GIP + GLP-1) to triple (retatrutide to adds glucagon). Tirzepatide was the first multi-receptor incretin agonist to reach broad clinical study.
What the research has examined
Tirzepatide has been studied across large clinical programs for metabolic endpoints. A 72-week phase 3 obesity trial (Jastreboff et al., *NEJM* 2022, SURMOUNT-1) examined its effect on body weight, and a head-to-head phase 3 trial in type 2 diabetes (Frías et al., *NEJM* 2021, SURPASS-2) compared it against semaglutide on glycemic endpoints. These are findings from controlled research trials, not a description of any outcome outside a study.
Limitations and open questions
- Investigational supply. Material here is a research compound, not an approved product, and is not for human use.
- Class-typical adverse events. Gastrointestinal effects (nausea, diarrhea) were the most commonly reported events in trials.
- Long-term data still accruing. Durability and safety beyond trial windows remain active research questions.
Supplied lyophilized for laboratory research use only. Not for human consumption.