VK2735 vs Semaglutide (2026): Phase 3 Dual GLP-1/GIP Agonist vs the GLP-1 Benchmark
VK2735 showed up to 14.7% weight loss at 13 weeks in Phase 2; semaglutide showed 14.9% at 68 weeks in STEP 1. See how mechanisms, dosing and status compare.
Research reference only. The information in this article is a summary of peer-reviewed scientific literature. It does not constitute medical advice and is not intended to guide human use. See our full disclaimer.
VK2735 vs semaglutide is the comparison researchers reach for when they want to know how far a next-generation dual incretin agonist has moved beyond the compound that defined the GLP-1 receptor agonist category. VK2735, developed by Viking Therapeutics, activates both the GLP-1 and GIP receptors and is in Phase 3 testing in the VANQUISH programme. Semaglutide, developed by Novo Nordisk, is a selective GLP-1 receptor agonist that is already approved for type 2 diabetes and chronic weight management and has the deepest outcomes dataset in the class. The two sit at opposite ends of the development timeline, so the useful question is what each dataset can and cannot tell researchers today.
Research reference only. All information on this page is a summary of peer-reviewed scientific literature and does not constitute medical advice. See individual library profiles for full compound data.
Quick Answer: VK2735 is an investigational dual GLP-1/GIP receptor agonist that produced up to 14.7% mean weight loss at 13 weeks in Phase 2 VENTURE, while semaglutide is an approved selective GLP-1 receptor agonist that produced 14.9% mean weight loss at 68 weeks in STEP 1. The figures come from trials of very different length and phase, so they are not directly comparable until VK2735's 78-week Phase 3 VANQUISH data report in 2027.
TL;DR:
- VK2735 targets two receptors (GLP-1 and GIP); semaglutide targets one (GLP-1).
- VK2735's longest reported data are 33 weeks from a September 2026 maintenance study; semaglutide has 68-week STEP 1 data and cardiovascular outcomes trials.
- Early VK2735 data suggest weight loss is largely retained on every-other-week or monthly maintenance dosing, an area where semaglutide is studied only weekly (injectable) or daily (oral).
- Semaglutide is FDA-approved; VK2735 remains investigational with Phase 3 topline data expected in the second half of 2027.
At a glance
| Feature | VK2735 | Semaglutide |
|---|---|---|
| Developer | Viking Therapeutics | Novo Nordisk |
| Receptor targets | GLP-1 + GIP (dual) | GLP-1 (selective) |
| Most advanced stage | Phase 3 (VANQUISH-1, VANQUISH-2) | Approved (FDA, EMA) |
| Headline weight-loss figure | Up to 14.7% at 13 weeks (Phase 2 VENTURE) | 14.9% at 68 weeks (Phase 3 STEP 1) |
| Dosing interval studied | Weekly induction; every-other-week and monthly maintenance explored | Weekly subcutaneous; daily oral |
| Oral formulation | Phase 2 complete; Phase 3 planned | Approved oral formulations |
VK2735: Mechanism and evidence base
VK2735 is a synthetic peptide engineered to activate both the glucagon-like peptide-1 receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor. GLP-1 receptor signalling in the hypothalamus and brainstem is associated with satiety and slowed gastric emptying, while GIP receptor engagement contributes glucose-dependent insulin secretion and has been studied for effects on adipocyte lipid handling and on the tolerability of GLP-1 agonism. This places VK2735 in the same mechanistic class as tirzepatide, although the two are distinct molecules with different receptor balance and pharmacokinetics. Full chemistry and trial details are on the VK2735 library profile.
The primary peer-reviewed dataset is the Phase 2 VENTURE study (PMID 41508550), a 13-week, randomized, double-blind, placebo-controlled trial in adults with obesity. Weekly subcutaneous VK2735 produced dose-dependent weight loss of up to 14.7% from baseline versus placebo, with gastrointestinal adverse events that became less frequent with continued dosing. A separate Phase 2 trial of an oral tablet formulation (NCT06828055) reported up to 12.2% mean weight loss at 13 weeks.
In September 2026, Viking reported topline results from an exploratory maintenance dosing study in 180 adults. After a 21-week weekly induction period at doses of 15–22.5 mg, mean weight loss ranged from approximately 16% to 19%. Participants who remained on weekly dosing through week 33 reached 21.7% mean weight loss, and the company reported no plateau at that point. Participants switched to every-other-week dosing retained 83–97% of their initial weight loss, and those switched to monthly dosing retained 82–90%, compared with 61% in the group switched to placebo. These are company-reported topline figures that have not yet been peer reviewed.
The pivotal programme consists of VANQUISH-1 (NCT07104500, about 4,500 participants with obesity or overweight) and VANQUISH-2 (NCT07104383, about 1,000 participants with type 2 diabetes and obesity or overweight). Both are 78-week placebo-controlled trials with enrollment complete and topline data expected in the second half of 2027.
Semaglutide: Mechanism and evidence base
Semaglutide is a GLP-1 analogue with two structural changes that underpin its long half-life: an Aib substitution at position 8 that resists DPP-4 degradation, and a C18 fatty diacid side chain that binds albumin. Together these give a half-life of roughly one week, which supports once-weekly subcutaneous administration. Because it is selective for the GLP-1 receptor, semaglutide is the standard reference compound against which dual and triple agonists are benchmarked. Mechanism detail, including cAMP/PKA/Epac2 signalling, is covered on the semaglutide library profile.
The obesity dataset centres on STEP 1 (PMID 33567185), a 68-week randomized, double-blind, placebo-controlled trial in 1,961 adults with overweight or obesity without diabetes. Once-weekly subcutaneous semaglutide 2.4 mg produced 14.9% mean weight loss versus 2.4% with placebo, with 86% of participants reaching at least 5% loss. The cardiovascular dataset began with SUSTAIN-6 (PMID 27633186) in type 2 diabetes and was extended to people without diabetes in the SELECT trial.
The long post-approval record also means semaglutide has a more detailed safety literature than any pipeline compound. One example is a 2026 case report (PMID 42027588) describing reversible central hypercapnia after dose escalation, a type of rare signal that only appears once a compound has been used widely. Investigational compounds such as VK2735 have not yet had enough exposure to generate comparable post-marketing data.
Side-by-side comparison
| Parameter | VK2735 | Semaglutide |
|---|---|---|
| Molecular class | Synthetic dual incretin peptide | Acylated GLP-1 analogue |
| Receptor activity | GLP-1R and GIPR agonist | GLP-1R agonist |
| Half-life extension | Extended half-life reported by sponsor; supports sub-weekly maintenance exploration | Albumin binding via C18 diacid; ~1 week |
| Routes studied | Subcutaneous; oral tablet | Subcutaneous; oral tablet |
| Longest reported efficacy data | 33 weeks (maintenance study, topline) | 68 weeks (STEP 1); multi-year outcomes trials |
| Peer-reviewed obesity trial | VENTURE, Obesity 2026 | STEP 1, NEJM 2021 |
| Cardiovascular outcomes data | None yet | SUSTAIN-6, SELECT |
| Regulatory status (US) | Investigational | FDA-approved |
| Primary research applications | Dual-agonist pharmacology, dosing-interval studies | GLP-1R reference agonist, outcomes and safety research |
Half-life values and study durations for a wider set of incretin compounds can be compared on the peptide half-life chart.
Differential research applications
Researchers typically select semaglutide when they need a well-characterised GLP-1 receptor reference. Its receptor selectivity, published pharmacokinetics and large outcomes literature make it the default comparator for isolating the contribution of GLP-1 signalling alone. Studies that ask whether a second receptor adds anything are usually designed with semaglutide or liraglutide as the single-agonist arm.
VK2735 is of interest for different questions. The first is whether adding GIP receptor agonism to GLP-1 agonism increases weight-loss magnitude or improves tolerability, a question first raised by tirzepatide and now being tested across several molecules. The second, specific to VK2735, is dosing frequency: the September 2026 maintenance data are among the first to test monthly administration of an incretin agonist after weekly induction. The third is formulation, since VK2735 is one of a small number of dual agonists with both injectable and oral versions in development.
For researchers placing VK2735 in the wider pipeline, the closest comparisons are to retatrutide, which adds glucagon receptor activity, and to tirzepatide, which shares the same receptor pair. Registered trial status for all of these compounds can be tracked in the clinical trial tracker.
The main limitation for any head-to-head interpretation is that no trial has compared VK2735 and semaglutide directly. Cross-trial comparisons are affected by differences in duration, baseline BMI, titration schedules, and whether results are reported as treatment-policy or on-treatment estimates.
Regulatory and compounding status
Semaglutide is FDA-approved for type 2 diabetes and chronic weight management and is authorised by the EMA. It was removed from the FDA drug shortage list in 2025, which ended the shortage-based allowance for large-scale compounding of copies. Semaglutide is not a named substance on the WADA Prohibited List.
VK2735 has no regulatory approval in any jurisdiction. As an investigational compound, it is not eligible for 503A or 503B compounding, and access is limited to registered clinical trials. Under WADA's S0 category, which covers pharmacological substances without approval for human therapeutic use, VK2735 is prohibited at all times in sport. Viking has stated that it is awaiting FDA feedback on dose selection and frequency for planned VANQUISH extension studies, expected to begin in late 2026 or early 2027.
Cited studies
- PMID 41508550 — "Weekly Subcutaneous VK2735, a GIP/GLP-1 Receptor Dual Agonist, for Weight Management: Phase 2, Randomized, 13-Week VENTURE Study" (Obesity, 2026). https://doi.org/10.1002/oby.70106
- PMID 33567185 — "Once-Weekly Semaglutide in Adults with Overweight or Obesity" (New England Journal of Medicine, 2021). https://doi.org/10.1056/NEJMoa2032183
- PMID 27633186 — "Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes" (New England Journal of Medicine, 2016). https://doi.org/10.1056/NEJMoa1607141
- PMID 42027588 — "Unexplained hypercapnia with normal pulmonary evaluation in a patient receiving semaglutide: a diagnostic challenge" (2026).
- Viking Therapeutics VK2735 maintenance dosing study topline results, as reported by MarketBeat, September 22, 2026: https://www.marketbeat.com/instant-alerts/event-viking-therapeutics-vk2735-shows-strong-weight-loss-retention-with-monthly-dosing-2026-09-22/
Frequently asked questions
Q: Is VK2735 more effective than semaglutide?
A: No head-to-head trial has been conducted, so relative efficacy has not been established. VK2735 reported up to 14.7% weight loss at 13 weeks in Phase 2, while semaglutide reported 14.9% at 68 weeks in Phase 3 STEP 1. Differences in trial length and design mean these figures cannot be compared directly.
Q: What is the difference between VK2735 and semaglutide?
A: VK2735 is a dual agonist of the GLP-1 and GIP receptors, while semaglutide is selective for the GLP-1 receptor. Semaglutide is approved and has multi-year outcomes data; VK2735 is investigational and in Phase 3.
Q: When will VK2735 Phase 3 results be available?
A: Viking Therapeutics has stated that topline data from VANQUISH-1 and VANQUISH-2 are expected in the second half of 2027. Both are 78-week placebo-controlled trials with enrollment already complete.
Q: Can VK2735 be dosed monthly?
A: An exploratory maintenance study reported in September 2026 found that participants switched from weekly to monthly dosing retained 82–90% of their initial weight loss over 12 weeks, compared with 61% after switching to placebo. These are preliminary company-reported results, and monthly dosing has not been tested in a pivotal trial.
Q: Is VK2735 similar to tirzepatide?
A: Both activate the GLP-1 and GIP receptors, so they belong to the same mechanistic class. They are different molecules from different developers, and tirzepatide is approved while VK2735 remains investigational.
See also:
- VK2735 vs Retatrutide: Which Investigational Incretin Agonist Leads the Injectable Obesity Pipeline? — compares VK2735 against the leading triple agonist.
- How Tirzepatide Differs from Semaglutide: Dual Agonist Mechanism — the established dual-versus-single agonist comparison that frames this one.
- Semaglutide Mechanism of Action: Complete GLP-1 Receptor Pharmacology and Clinical Evidence Reference — detailed receptor pharmacology for the GLP-1 benchmark compound.
For laboratory research purposes only. Not for human or animal consumption. Compounds described are not approved by the FDA for human or veterinary use unless explicitly stated.