UBT251 (Vistrutide): GLP-1/GIP/Glucagon Triple Agonist Research Overview

UBT251 belongs to the triple agonist class: single peptides engineered to activate three related hormone receptors. These are the receptors for glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon. Its developer describes it as a long-acting triple agonist, meaning the peptide is modified to circulate far longer than the native hormones, which are cleared within minutes.

Triple agonists build on two earlier generations of incretin research peptides. Single agonists act on the GLP-1 receptor alone. Dual agonists, such as tirzepatide, act on GLP-1 and GIP receptors. Adding glucagon receptor activity makes UBT251 a tool for studying how all three pathways interact when engaged by one molecule. That question is also central to research on retatrutide, the best-known triple agonist.

For background on the class, see what a triple agonist research peptide is.

The developer and its partner refer to the molecule only as UBT251. We have not found the name “Vistrutide” in any developer announcement, trial registration or journal article. It appears to be a name used by research suppliers. You may see both names on product listings and certificates of analysis. If an official nonproprietary name (INN) is assigned, it will appear in the WHO International Nonproprietary Names lists.

Because the names vary, the reliable way to confirm what a vial contains is its batch documentation. A certificate of analysis should report the observed molecular mass by mass spectrometry and match it to the expected value for the batch.

All three UBT251 targets are class B1 (secretin-family) G protein-coupled receptors. They share a two-domain binding mechanism. The C-terminal part of the peptide is captured by the receptor’s large extracellular domain, and the N-terminal part then inserts into the transmembrane core to activate the receptor.

• GLP-1 receptor (GLP-1R): activated by the incretin hormone GLP-1; studied in pancreatic beta-cell, gut and central nervous system models.
• GIP receptor (GIPR): activated by the second incretin hormone, GIP; studied in pancreatic islet and adipose tissue models.
• Glucagon receptor (GCGR): activated by glucagon; expressed mainly in the liver and studied in models of hepatic glucose output and lipid metabolism.

All three receptors couple mainly to G_s, raising intracellular cAMP. They can also recruit β-arrestins and activate downstream kinases such as ERK1/2. For a single multi-receptor peptide, the key research question is the balance of its activity across the three receptors. Small changes in that balance can shift the overall pharmacological profile, which is why triple agonists from different developers are compared receptor by receptor.

In vitro, UBT251 is used as a tool compound in incretin and glucagon receptor pharmacology. Typical approaches include:

• cAMP accumulation assays (HTRF, luminescence or reporter-gene formats) in cell lines expressing human GLP-1R, GIPR or GCGR one at a time
• Potency and efficacy comparison across the three receptors, reporting EC₅₀ and E_max side by side against the native hormones
• β-arrestin recruitment and receptor internalization assays to profile signaling bias
• Ligand binding studies to estimate affinity at each receptor
• Comparator studies alongside other single, dual and triple agonists, such as tirzepatide and retatrutide, to place UBT251’s receptor balance in context
• Stability studies in buffer and plasma to examine the modifications that extend its half-life

When comparing data across studies, keep cell line, receptor expression level and assay format the same. Potency at class B1 receptors is sensitive to all three.

UBT251 and retatrutide share the same three targets but are separate molecules from separate discovery programs. Their receptor balance, structure and pharmacokinetics should not be assumed to match. For amylin-pathway peptides, which act on a different receptor system, see the Eloralintide research overview. For a wider view of metabolic receptor targets, see the metabolic peptide receptor overview.

UBT251 is an investigational molecule and is not an authorized product for any use. Public milestones so far:

• Phase 1 in China. TUL reported an early Phase 1 study with linear pharmacokinetics and a mean half-life of roughly 137 to 170 hours (about six to seven days), consistent with its long-acting design.
• License to Novo Nordisk (March 2025). On 24 March 2025, TUL and Novo Nordisk announced an exclusive license. Novo Nordisk takes the rights to develop, manufacture and commercialize UBT251 worldwide outside mainland China, Hong Kong, Macau and Taiwan. TUL’s subsidiary keeps those territories. The announced terms were a US$200 million upfront payment, up to US$1.8 billion in milestone payments, and tiered royalties.
• Phase 2 in China. TUL has reported topline results from two Phase 2 studies in China in metabolic indications.
• Global Phase 1b/2a study. Novo Nordisk is running a study of around 330 participants lasting up to 28 weeks, which examines safety, tolerability, pharmacokinetics and pharmacodynamics. Topline data are expected in 2027.

For current study designs, search ClinicalTrials.gov for UBT251. For peer-reviewed literature, see PubMed. Clinical findings are reported by the developers and should be read in the original sources. This page doesn’t summarize them.

Research-grade UBT251 is supplied as a lyophilized peptide. Supplier names for the molecule vary, so batch documentation matters more than the label. A complete certificate of analysis should include:

• Identity by mass spectrometry (ESI-MS or MALDI-TOF): the observed mass compared with the expected molecular weight
• Purity by reversed-phase HPLC with UV detection, reported as percent area of the main peak
• Lot number and test date, so every result traces to the vial in hand
• Endotoxin results (LAL) where material is intended for cell-based assays
• Appearance and net peptide content, which matter for preparing accurate stock concentrations

Learn how to read one in our guide to the peptide certificate of analysis, and see HPLC testing for peptides and endotoxin testing. NuRev publishes batch certificates in its COA library.

Long-acting incretin peptides are larger and more hydrophobic than many short research peptides. Handle them with care to limit aggregation and adsorption to plastics. General practice for lyophilized peptides applies:

• Store the sealed vial at −20 °C, protected from light and moisture. Short-term storage at 2–8 °C is acceptable.
• Let the vial reach room temperature before opening to limit condensation.
• Dissolve in a solvent suited to the assay, mix gently rather than vortexing hard, and divide solutions into single-use aliquots.
• Avoid repeated freezing and thawing, and use low-binding tubes and tips at low concentrations.

More detail is in peptide storage best practices and preparing lyophilized peptide solutions for laboratory assays.

NuRev supplies research peptides for laboratory and in-vitro research use only. They are not for human or veterinary use.