VK2735
Viking Therapeutics' GLP-1 and GIP dual agonist, with both a weekly injection and a daily tablet in late-stage trials and unusually fast early weight loss.
Also known as Viking dual agonist, VK2735
Human RCT — Randomised controlled trials in humans, but not an approved product for this use.
Phase 2 VENTURE showed about 14.7% weight loss at 13 weeks subcutaneously, and phase 3 VANQUISH-1 (roughly 4,650 participants) and VANQUISH-2 have completed enrolment with results pending. Promising but unfinished, and it is one of the most commonly counterfeited peptides in the grey market.
How it works
VK2735 activates both the GLP-1 and GIP receptors, combining incretin-driven insulin secretion, delayed gastric emptying and central satiety with the GIP-mediated effects on adipose lipid handling and nausea tolerance. Its distinguishing feature is not novel pharmacology but formulation breadth: the same molecule has been advanced as both a once-weekly subcutaneous injection now in two phase 3 trials, and as an oral tablet, which is technically difficult for a peptide of this class. Phase 2 VENTURE data showed unusually rapid early weight loss - about 14.7% by 13 weeks - though short trials flatter fast-acting agents.
Targets: GLP-1 receptor, GIP receptor
Dosing
| Protocol | Dose | Frequency | Route |
|---|---|---|---|
| VENTURE phase 2 subcutaneous dosingSame day each week. | 2.5 mg – 15 mg | once weekly | subcutaneous |
| VENTURE-Oral phase 2 dosingDaily tablet. | — | once daily | oral |
- · Phase 2 escalated from 2.5 mg weekly through 5, 10 and 15 mg. Phase 3 VANQUISH-1 and VANQUISH-2 use weekly subcutaneous dosing over 78 weeks.
- · The oral programme escalates over 13 weeks; published dose arms are reported inconsistently in secondary sources so no milligram figure is given here.
Titration
Four-weekly steps in the subcutaneous programme, mirroring tirzepatide.
Cycling
Chronic therapy in design.
Pharmacology
- Half-life
- The subcutaneous form supports once-weekly dosing; the oral form is dosed daily.
- Onset
- Weight loss was evident within the first few weeks in phase 2.
- Routes
- subcutaneous, oral
- Molecule
- Dual GLP-1/GIP receptor agonist peptide
Handling
- Diluent
- Bacteriostatic water for research-grade material
- Typical mix
- 1 or 2 mL
- Lyophilised
- Refrigerate at 2-8 C.
- Reconstituted
- Refrigerated, use within about 28 days.
- Light sensitive
- Yes — keep it out of the light
Mixing
VK2735 is heavily counterfeited in the grey market; there is no reference standard available to consumers.
Side effects
- very commonNausea— Standard incretin profile; higher in the oral formulation in early trials.
- commonVomiting
- commonDiarrhoea and constipation
- commonLoss of lean mass— Expected given the rate of weight loss.
Do not use if
- Pregnancy.
- History of pancreatitis - class caution.
- Personal or family history of medullary thyroid carcinoma or MEN2 - class caution.
- Long-term safety unknown; phase 3 is ongoing.
Combining it
- redundanttirzepatide — Same dual-receptor mechanism.
- redundantsemaglutide — GLP-1 agonism already present.
- cautioninsulin-analogues — Hypoglycaemia risk in combination.
What to monitor
- · Weight and body composition.
- · HbA1c.
- · Heart rate.
- · Liver enzymes - the oral programme has been watched closely for hepatic signals.
Legal status
Investigational; not approved anywhere. Any consumer-facing supply is unregulated research material.
References
- Viking Therapeutics 2024, VENTURE phase 2 subcutaneous trial results (trial)
- Viking Therapeutics 2026, VENTURE-Oral phase 2 data presented at ECO (trial)
- VANQUISH-1 and VANQUISH-2 phase 3 trial designs (trial)
Mechanism in depth
VK2735 is mechanistically the same idea as tirzepatide - simultaneous GLP-1 and GIP receptor agonism - with a different molecule and a different receptor balance that the sponsor has not disclosed in detail. What is distinctive is the speed of the early weight-loss curve: the VENTURE phase 2 study reported about 14.7% mean weight loss at 13 weeks, which is faster than tirzepatide's early trajectory. Fast early loss is not automatically good news. It correlates with larger lean-mass loss, and it is also the signature of trials with aggressive escalation and short duration, where the curve has not had time to flatten. The other genuinely interesting element is the oral tablet, which is a peptide rather than a small molecule and therefore faces the same absorption problem oral semaglutide does. Phase 3 VANQUISH-1, with roughly 4,650 participants, and VANQUISH-2 completed enrolment with results pending as of mid-2026, so the picture is incomplete. Practically, VK2735 has a specific problem that has nothing to do with its pharmacology: it is among the most frequently counterfeited peptides in the grey market, precisely because it is well known, unavailable and expensive to synthesise correctly.
What usually goes wrong
Product identity is the dominant failure mode here, more than for almost any other compound in this class. VK2735 has no legitimate consumer supply, high name recognition and a complex synthesis, which is exactly the profile that attracts substitution - most commonly with cheaper tirzepatide or with nothing at all. Beyond that, the 13-week phase 2 design encourages people to expect 14.7% in three months and to escalate accordingly, which is a lean-mass and tolerability problem.
Bloodwork worth running
| Marker | When | Why it matters |
|---|---|---|
| Body composition by DEXA | Baseline and every 3 months. | Fast early weight loss is the pattern most associated with disproportionate lean-mass loss.Act if: No established threshold; treat lean loss above a third of total as a signal to slow escalation. |
| HbA1c and fasting glucose | Baseline and 3-monthly. | Dual incretin agonism lowers glucose substantially.Act if: Hypoglycaemia on background insulin or sulfonylurea means cut that agent. |
| Creatinine and eGFR | Baseline and after prolonged vomiting. | Rapid weight loss with significant gastrointestinal side effects is a dehydration setup.Act if: A 30% rise means stop and rehydrate. |
| ALT and AST | Baseline and 3 months. | Liver fat falls with effective incretin therapy; a rise is unexpected and, on unregulated material, could reflect what else is in the vial.Act if: Any unexplained rise on grey-market material means stop and question the product. |
Pharmacokinetics
- Crosses blood-brain barrier
- partial
- Accumulates
- Yes — doses stack before steady state
- Metabolism
- Presumed proteolytic degradation plus beta-oxidation of the acyl chain.
- Elimination
- Presumed catabolic.
Receptor targets
- GLP-1 receptor (GLP1R) — Not verified; the receptor balance has not been publicly disclosed in detail
Appetite suppression, delayed gastric emptying, glucose-dependent insulin secretion.
- GIP receptor (GIPR) — Not verified
Insulin sensitisation, adipose lipid buffering, and probable central contribution to tolerability, as with tirzepatide.
Trials
- VENTURE Phase 2 · n=176 · 13 weeks · 2026
Mean weight reduction of approximately 14.7% at 13 weeks with weekly subcutaneous VK2735 at the top dose.
What to expect, and when
Weight loss was evident within the first few weeks in phase 2 and reached about 14.7% by 13 weeks. Longer-term trajectory is unknown because the phase 3 results had not published as of mid-2026.
Stacking and comparisons
Contains full GLP-1 and GIP agonism, so it is redundant with tirzepatide, semaglutide and retatrutide. An amylin analogue would be the mechanistically non-overlapping addition and there is no data for it. Given the counterfeiting problem, the single most valuable thing you can add to a VK2735 protocol is a third-party mass-spec identity test on the actual vial you intend to use.
Against tirzepatide: the same two receptors, faster early loss in a much shorter trial, and no approval. Tirzepatide has 72-week phase 3 data and a supply chain; VK2735 has a 13-week phase 2 and a counterfeiting problem. Against orforglipron: both are chasing the oral market, but orforglipron is a small molecule that is genuinely orally bioavailable and approved, while VK2735's oral form is a peptide facing the same absorption ceiling as oral semaglutide.
Rough cost
$80–$300/month. Grey market only; no legitimate supply exists. Market observation, not verified pricing, and the counterfeiting rate makes price a poor signal of what you are getting.
Genuinely uncertain
- No verifiable pharmacokinetic parameters.
- The GLP1R-to-GIPR potency ratio has not been publicly disclosed in verifiable detail.
- No published titration ladder could be verified.
- VANQUISH-1 and VANQUISH-2 phase 3 results had not published in a form that could be verified as of this session.
- The 176-participant figure for VENTURE was not individually re-verified against the paper.
- Cost figures are market observations, not verified pricing.
Papers
- Weekly Subcutaneous VK2735, a GIP/GLP-1 Receptor Dual Agonist, for Weight Management: Phase 2, Randomized, 13-Week VENTURE Study Bays HE et al., Obesity (Silver Spring), 2026 · PMID 41508550
The peer-reviewed VENTURE phase 2 result.