Tirzepatide is a dual GIP/GLP-1 receptor agonist peptide developed by Eli Lilly. Unlike most compounds in this index, it is an approved medicine, sold as Mounjaro (type 2 diabetes) and Zepbound (weight management), which makes its gray-market “research peptide” form a very different proposition from unapproved compounds.
It activates both the GIP and GLP-1 receptors, combining appetite suppression, slowed gastric emptying, and improved insulin response. In its pivotal weight-management trial (SURMOUNT-1), the highest dose averaged roughly 21% body-weight reduction at 72 weeks.
The pharmacy product is manufactured under pharmaceutical GMP with verified contents. Research-grade tirzepatide is lyophilized powder from unregulated suppliers, its quality proven only by whatever third-party testing a vendor publishes. Regulators in the US and Canada have moved against unauthorized sellers, and enforcement is stricter for compounds with an approved counterpart. That gap is exactly what published batch testing exists to measure.
Working out reconstitution or syringe units? Use the free peptide calculator, then check your batch’s published test result before trusting the label: in 2024, roughly 43% of research peptides submitted to Janoshik Analytical missed their label claims.
Vendor rankings on PeptideCensus are computed only from publicly published third-party lab results; see the vendor index and how scoring works.
Gastrointestinal effects are the most commonly reported in the approved product’s labeling (nausea, vomiting, constipation, diarrhea), typically dose-related and worst during escalation. Gray-market vials add unverified content risk on top.
Yes: a synthetic 39-amino-acid peptide engineered to activate two incretin receptors.
It is sold “for research use only.” Because approved versions exist, unauthorized sales and imports face stricter enforcement than unapproved compounds, including FDA action against sellers and border seizures in Canada.
Both are approved GLP-1-class drugs; tirzepatide adds GIP activity and posted larger average weight reductions in its trials. See the semaglutide hub.
Price and access: pharmacy list prices run high without coverage. The trade-off is unverified contents, which is what batch testing measures.
PeptideCensus aggregates publicly published third-party lab results and links every number to its source. Nothing on this page is medical advice; research compounds are not for human use.