What is VK2735, and how does Viking's GLP-1/GIP drug compare?

The short answer

VK2735 is Viking Therapeutics' investigational obesity drug — a dual GLP-1/GIP receptor agonist (the same receptor combination as tirzepatide) being developed in both injectable and oral forms. In Phase 2 trials, the weekly injection produced up to about 14.7% weight loss at 13 weeks and the daily pill up to about 12.2%. It is not approved; Phase 3 is being planned.

Evidence tier: Tier 1 for the published/announced trial results; Tier 2 for cross-trial comparisons. Educational content, not medical advice.

The key points:

• Same mechanism as tirzepatide: dual GLP-1 + GIP receptor agonist
• Two formats: weekly injectable and daily oral tablet
• Phase 2: up to ~14.7% (injectable) and ~12.2% (oral) at 13 weeks
• Not approved — Phase 3 in planning; tolerability/dropout is the watch item

For the drug-class background, see the GLP-1 complete guide.

What is VK2735?

Evidence tier: 2 — established pharmacology.

VK2735 is an investigational metabolic drug from Viking Therapeutics, a dual agonist of the GLP-1 and GIP receptors — the same two-receptor combination used by tirzepatide (Mounjaro/Zepbound). The GLP-1 component reduces appetite and slows gastric emptying; the GIP component adds complementary metabolic effects. What makes VK2735 notable isn't a novel mechanism — it's that Viking is advancing it in both a weekly subcutaneous injection and a once-daily oral tablet, positioning it to compete on delivery format as well as efficacy.

That dual-format strategy is the strategic heart of the program. The injectable aims to compete head-on with established GLP-1/GIP therapy, while the oral tablet targets the large group of patients who would prefer a pill — a segment where options are currently limited and absorption is technically hard (the same challenge covered in oral GLP-1 absorption and CYP3A4). Because the mechanism is well-trodden, VK2735's case rests less on "does this pathway work" — it clearly does — and more on whether Viking can deliver competitive efficacy, acceptable tolerability, and a viable oral option as a smaller challenger to the incumbents.

It's worth being clear about why "same mechanism as tirzepatide" is not a criticism. Reusing a validated pathway lowers the scientific risk: the GLP-1/GIP combination is already proven in humans to drive large weight loss, so the question for VK2735 is execution, not whether the biology works. That's actually a more favorable starting point than a first-in-class mechanism whose human effects are unknown. The flip side is that a me-too-mechanism drug has to win on something other than novelty — efficacy at least matching the incumbents, a genuinely usable oral form, tolerability, manufacturing, and price. Viking's bet is that it can compete on that combination, particularly the oral tablet, rather than on a unique receptor story.

How much weight loss does VK2735 cause?

Evidence tier: 1 — Phase 2 trials (injectable peer-reviewed).

The strongest data come from the subcutaneous Phase 2 VENTURE trial, a 13-week randomized study published in the peer-reviewed journal Obesity (Bays et al. 2026, doi:10.1002/oby.70106; trial NCT06068946). Participants on weekly injectable VK2735 lost up to about 14.7% of body weight from baseline at 13 weeks, with no sign of plateau — a steep trajectory over a short window that suggested more weight loss would follow with longer treatment. That's a competitive Phase 2 result for the injectable.

The oral tablet then delivered its own Phase 2 readout from the VENTURE-Oral trial (NCT06828055), with once-daily dosing producing up to about 12.2% mean weight loss at 13 weeks and a clear dose-response, meeting its primary and secondary endpoints. Earlier, a Phase 1 oral study had shown up to roughly 8.2% by day 28. Taken together, the picture is consistent: VK2735 produces meaningful weight loss in both formats, with the injectable somewhat ahead of the pill — as you'd expect given the absorption limits of oral peptides. As always, these are 13-week Phase 2 results, and the durability and magnitude over a full Phase 3 course remain to be confirmed.

Is the oral version as good as the injection?

Evidence tier: 1–2 — trial data plus interpretation.

Not quite, and that's the expected pattern. Across the GLP-1 class, oral peptide formulations generally deliver somewhat less than their injectable counterparts because only a fraction of an oral peptide dose survives digestion and is absorbed. VK2735's ~12.2% oral versus ~14.7% injectable at the same 13-week mark fits that pattern — the pill is clearly effective, just a step behind the shot. For many people, a convenient daily pill that delivers double-digit weight loss is an attractive trade even if it's not the absolute maximum.

The genuine open question for the oral program is tolerability and adherence. Viking's oral readouts drew some investor concern over discontinuation and dropout rates in trial participants — a reminder that a pill is only useful if people can take it consistently without GI side effects driving them off it. So the oral story isn't simply "smaller number than the injection"; it's whether the daily-dosing experience is comfortable enough for real-world persistence. That's exactly the kind of question short Phase 2 trials can hint at but only larger, longer studies can answer, and it's worth watching as the program advances.

How does VK2735 compare to tirzepatide and the pipeline?

Evidence tier: 2 — cross-trial comparison, not head-to-head.

Mechanistically, VK2735 is the closest pipeline analogue to tirzepatide — both are GLP-1/GIP dual agonists — so its differentiation is about format and competition rather than a new pathway. Against the broader next-generation field, the receptor combinations now span: GLP-1/GIP (tirzepatide, VK2735), GLP-1/glucagon (survodutide), GLP-1/amylin (amycretin), GLP-1 + GIP-antagonist (MariTide), and the GLP-1/GIP/glucagon triple agonist (retatrutide) (next-gen multi-agonists overview; survodutide; amycretin).

The essential caveat applies in full: these are cross-trial comparisons, not head-to-head. VK2735's ~14.7% came from a 13-week study; tirzepatide's headline figures come from much longer Phase 3 trials, so the numbers aren't directly rankable. What's fair to say is that VK2735's Phase 2 efficacy is competitive for its class and stage, and that its real significance is as a credible challenger with a viable oral option from a smaller company — a dynamic that could matter for pricing and access if it reaches the market. Whether it gets there depends on Phase 3 confirming both the efficacy and the tolerability.

What's the status, and should you wait for it?

Evidence tier: 2 — regulatory status plus practical reasoning.

VK2735 is investigational and not approved anywhere, with Phase 3 in planning following the Phase 2 readouts. In practical terms, that means it is years — not months — from any possible pharmacy availability, assuming the Phase 3 program succeeds and clears regulatory review. Anyone hoping to "get VK2735" today cannot do so legitimately, and products marketed online under that name are gray-market research chemicals with no guarantee they contain the actual compound, at the stated dose, free of contamination — the same authenticity problems detailed in spotting counterfeit peptides.

So is it worth waiting for? For most people the honest answer is that there's no reason to wait for VK2735 specifically when effective, approved options already exist. VK2735's interest is competitive and structural: a credible challenger with an oral option could, if approved, expand choice and pressure pricing in a market dominated by a few players. That's a reason to follow the program with interest, not a reason to delay evidence-based treatment now. The drug's value to a prospective patient is entirely contingent on Phase 3 success and approval — neither of which is guaranteed, however good the Phase 2 numbers look. Treat it as a promising name on the horizon, and make current decisions based on what's actually available and proven today, with a clinician.

Limitations

This is educational content, not medical advice.

• Efficacy data are 13-week Phase 2 — promising, but durability and full magnitude await Phase 3.
• The oral version trails the injectable modestly, consistent with oral peptide absorption limits.
• Tolerability/adherence is the key oral-program question — discontinuation rates warrant attention.
• Cross-trial comparisons aren't head-to-head — don't directly rank VK2735 vs tirzepatide numbers.
• Not approved anywhere — online "VK2735" is gray-market and not genuine.
• Marko Maal, MSc Pharmacy reviewed this article. Reviewer attribution does not constitute a doctor-patient relationship.

The bottom line

VK2735 is Viking Therapeutics' dual GLP-1/GIP agonist — mechanistically similar to tirzepatide, but advancing in both weekly injectable and daily oral forms. Phase 2 trials showed up to ~14.7% weight loss with the injection and ~12.2% with the pill over 13 weeks, both with strong dose-response. Its significance is less about a novel mechanism and more about being a credible challenger with a viable oral option, which could matter for competition and access. It's investigational and not approved, so any "VK2735" sold online is fake. The efficacy looks competitive; the open questions are oral-program tolerability and whether Phase 3 confirms the early trajectory.

Related on this site

• GLP-1 complete guide
• Next-gen multi-agonists overview
• Survodutide (glucagon/GLP-1) explained
• Amycretin (GLP-1/amylin) explained
• Oral GLP-1 absorption & CYP3A4
• Our evidence-tier framework

References

• Bays HE, et al. 2026. Weekly Subcutaneous VK2735, a GIP/GLP-1 Receptor Dual Agonist, for Weight Management: Phase 2, Randomized, 13-Week VENTURE Study. Obesity. doi:10.1002/oby.70106 — subcutaneous Phase 2 efficacy.
• VENTURE-Oral Dosing Trial of VK2735 in obesity (Phase 2). ClinicalTrials.gov NCT06828055 — oral tablet Phase 2.
• Phase 1 study of VK2735 safety and tolerability. ClinicalTrials.gov NCT05203237 — first-in-human safety and dosing.