What does VK2735 target?

The GIP and GLP-1 receptors — the same pair as tirzepatide.

How long did the Phase 2 run?

Thirteen weeks, in the randomised VENTURE study published in Obesity in March 2026.

Can its result be compared with tirzepatide's?

Not directly. Weight curves have not flattened at 13 weeks, so comparing against a 72-week figure understates the shorter trial.

GLP-1 & Incretin Science

A Second Entrant to Tirzepatide's Mechanism

JMWritten & reviewed by Jack Muncaster · Founder, UK PeptidesLast reviewed 2026-08-233 cited sources

VK2735 is a dual agonist of the GIP and GLP-1 receptors, the same receptor pair tirzepatide engages. Bays and colleagues published the Phase 2 randomised VENTURE study of weekly subcutaneous VK2735 over 13 weeks in Obesity in March 2026.

Key facts

Class: GIP/GLP-1 receptor dual agonist
Administration: Weekly subcutaneous
Trial: VENTURE, Phase 2, randomised
Duration: 13 weeks
Published: Obesity, March 2026 (PMID 41508550)
Same targets as: Tirzepatide
Authorisation: None — investigational

What it is

A dual agonist engaging both the GIP and GLP-1 receptors — the combination tirzepatide established. Entering a mechanism another compound has already validated is a different proposition from opening a new one: the biology is settled, and the question becomes whether this molecule does it better, more tolerably, or more cheaply.

Why 13 weeks is short, and why that is appropriate

Phase 3 obesity trials run 68 to 80 weeks because weight reduction continues accumulating over that period. Thirteen weeks cannot capture a plateau. It can establish whether the compound is tolerated, whether it produces the expected direction and rough magnitude of effect, and whether to commit to a much larger programme — which is what Phase 2 is for.

Research material referenced

Retatrutide 10mg — third-party HPLC tested

View — £59.99

How to read an early figure against a late one

Weight reduction curves have not flattened at three months. A 13-week figure compared against tirzepatide's 72-week result understates the shorter trial, and comparing them directly is the cross-trial error this site keeps returning to. Duration is one of the variables that must match before two numbers mean the same thing.

Why a second GIP/GLP-1 agonist is worth developing

A validated mechanism removes the largest risk in drug development — that the target does not work. What remains is molecular: potency ratio between the two receptors, half-life, tolerability profile, manufacturing cost. Those are real differences, and they are where a second entrant either finds a position or does not.

What Phase 2 does not establish

Durability, cardiovascular or other outcome benefit, or performance against an active comparator. Almost every compound in this class has looked promising at Phase 2. The site has already documented what happens next — programmes withdrawn, non-inferiority missed, hepatic signals emerging — and Phase 3 is where those appear.

Regulatory position

VK2735 holds no marketing authorisation from the MHRA, EMA or FDA and is available only within registered clinical trials. Nothing supplied on this site is related to it or is an alternative to any licensed weight-management medicine.

Extended research context

The GLP-1 & Incretin Science deep dive

Deep dive: the two routes to a bigger effect

Every compound trying to beat GLP-1 alone has taken one of two routes. The first adds more receptors from the same hormone family — GIP in tirzepatide, GIP and glucagon in retatrutide. The second adds a non-incretin satiety hormone, which in practice means amylin: CagriSema combines cagrilintide with semaglutide, and amycretin engages both receptors from one molecule. Both routes work, because they recruit signalling pathways that do not fully overlap. Neither has escaped the constraint that binds all of them, which is that gastrointestinal tolerability worsens as effect size grows.

Deep dive: why a percentage is not a result

The most-quoted numbers in this field are the least comparable. REDEFINE 1 reported 22.7% and 20.4% for the same compound in the same trial — the first among participants who adhered to treatment, the second across everyone randomised. TRIUMPH-1 reported 28.3% in an uncomplicated obesity population while TRIUMPH-3 reported up to 22.6% in adults with established cardiovascular disease, using the same compound. Before any two figures can be compared they have to match on estimand, population, duration, comparator and whether the number is placebo-adjusted. Most published comparisons match on none of them.

Deep dive: what happens after the trial stops

Every headline figure describes weight while treatment continues. The STEP-1 extension found that a year after semaglutide was stopped, participants had given back roughly two-thirds of what they lost, moving from 17.3% mean reduction to a net 5.6% — though average weight remained below baseline and nearly half stayed at least 5% down. Meta-analysis puts regain at around 0.8 kg per month. This is why maintenance studies such as TRIUMPH-6 matter more to the field's future than another two points of peak reduction.

Research applications

▸Comparing incretin and amylin compounds on a like-for-like basis
▸Interpreting estimands, thresholds and placebo-adjusted figures in trial reports
▸Tracking the obesity pipeline across sponsors and jurisdictions
▸Understanding receptor pharmacology behind GLP-1, GIP, glucagon and amylin
▸Distinguishing licensed medicines from investigational compounds

Handling checklist

✓Identify which estimand a quoted percentage comes from before citing it
✓Check the trial population and baseline BMI against the comparison you are making
✓Confirm the duration and whether the reduction curve had plateaued
✓Read discontinuation rates alongside efficacy figures
✓Verify every NCT identifier against ClinicalTrials.gov rather than secondary reporting

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Comparing headline percentages across different trials

Fix: Population, duration, estimand and comparator all differ; the numbers are not interchangeable.

✗ Quoting the larger of two figures from the same trial

Fix: Name the estimand. Efficacy and treatment-policy answer different questions.

✗ Treating peak reduction as a durable outcome

Fix: Substantial regain follows cessation across the class; peak figures describe a maintained state.

✗ Assuming an oral route means a weaker mechanism

Fix: Route and receptor count are independent. Orforglipron is weaker because it hits one receptor, not because it is a tablet.

✗ Reading investigational compounds as available treatments

Fix: Most of this pipeline holds no authorisation anywhere; mazdutide is approved only in China.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Frequently asked questions

What does VK2735 target?: The GIP and GLP-1 receptors — the same pair as tirzepatide.
How long did the Phase 2 run?: Thirteen weeks, in the randomised VENTURE study published in Obesity in March 2026.
Can its result be compared with tirzepatide's?: Not directly. Weight curves have not flattened at 13 weeks, so comparing against a 72-week figure understates the shorter trial.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

Written and reviewed by

Jack Muncaster · Founder, UK Peptides

Jack founded UK Peptides in Manchester after repeatedly receiving research compounds with missing or recycled paperwork. He is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate.

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