2026-08-21 · VK2735, Viking Therapeutics, GLP-1, GIP, dual agonist, oral GLP-1, next-generation obesity drug, obesity pipeline

What is VK2735?

VK2735 is Viking Therapeutics' investigational small-molecule dual GLP-1 and GIP receptor agonist, developed in parallel as a weekly subcutaneous injection and a daily oral tablet. It activates the same two receptors as tirzepatide (Zepbound) but is being built in both injectable and pill formulations to give patients a choice between a weekly shot and a daily oral. VK2735 is not FDA-approved and is not available through any legitimate pharmacy or compounding channel in 2026.

How does VK2735 compare to tirzepatide (Zepbound)?

VK2735 and tirzepatide target the same two receptors — GLP-1 and GIP. Tirzepatide is a peptide given as a weekly subcutaneous injection and has produced roughly 20.9 percent weight loss at 72 weeks in SURMOUNT-1 (Jastreboff 2022 NEJM). VK2735 is a small molecule (non-peptide) in parallel injectable and oral development. Its VENTURE-1 Phase 2 SC readout showed roughly 14.7 percent placebo-adjusted weight loss at just 13 weeks at the 5 mg dose — the largest short-window Phase 2 obesity signal reported so far — but the direct head-to-head against tirzepatide does not exist and the 52-week magnitude will not be known until Phase 3 reads out.

When will VK2735 be FDA-approved?

The realistic earliest FDA availability is 2028 to 2029 for the subcutaneous formulation and 2030 or later for the oral tablet. Viking Therapeutics has publicly guided VK2735 SC into a Phase 3 obesity program with enrollment starting late 2025 into 2026 and a primary readout targeted for 2027 to 2028. A standard 12 to 18 month FDA review after a 2028 submission puts the SC form on US pharmacy shelves in 2028 or 2029 at the earliest. The oral tablet is two to three years behind.

Is VK2735 an oral pill or an injection?

Both, in parallel development. VK2735 SC is a once-weekly subcutaneous injection currently in Phase 2 and Phase 3, and VK2735 oral is a once-daily tablet in Phase 1. It is the only small-molecule GLP-1/GIP dual agonist being developed in both formulations at the same time — every other post-tirzepatide next-generation drug is single-formulation. The oral bioavailability and any fasting-water dosing rule for the tablet have not been finalized because the Phase 1 oral study is still running.

How much weight did people lose on VK2735 in Phase 2?

In the VENTURE-1 Phase 2 subcutaneous obesity trial (Viking Therapeutics topline, March 2024), 176 adults with obesity received placebo or weekly VK2735 SC for 13 weeks. At the 5 mg dose, mean placebo-adjusted weight loss was roughly 14.7 percent at week 13. That number is the largest short-timeframe weight loss ever reported for a Phase 2 obesity trial — semaglutide reached about 6 percent and tirzepatide about 8 percent in equivalent early 12-week windows. The 13-week timeframe is short, so the 52-week Phase 3 magnitude is genuinely unknown.

Is compounded VK2735 available?

No. VK2735 is a small-molecule non-peptide, has never been on the FDA drug-shortage list, and has no legitimate 503A or 503B compounding pathway. No compounding pharmacy, telehealth clinic, or research-chemical vendor has legal or reliable access to the Viking Therapeutics investigational product. Anything sold in 2026 under the name 'VK2735' is mislabeled, an unrelated compound, or counterfeit and should not be injected or swallowed. Read our compounded semaglutide and tirzepatide safety guide for the 2026 enforcement landscape.

How is VK2735 different from orforglipron?

Both are small-molecule non-peptide oral drugs in the next-generation pipeline, but the receptor targets differ. Orforglipron (Eli Lilly) is a pure GLP-1 receptor agonist — one receptor, oral daily tablet with no fasting-water rule, Phase 3 ATTAIN complete and FDA action expected 2026 to 2027. VK2735 oral is a dual GLP-1 and GIP agonist — two receptors, still in Phase 1 for the oral form. If both approve, orforglipron becomes the first true daily oral GLP-1 without a fasting window and VK2735 oral becomes the first daily oral tirzepatide-class dual agonist, roughly two to three years behind.

Should I wait for VK2735 or start Wegovy or Zepbound now?

For most adults with obesity who are candidates for pharmacotherapy in 2026, waiting is not the right answer. VK2735 SC is realistically three years away and the oral form is five or more. During that wait, untreated obesity accumulates cardiovascular, metabolic, joint, and psychological burden. Wegovy (semaglutide 2.4 mg, roughly 15 percent at 68 weeks) and Zepbound (tirzepatide 15 mg, roughly 21 percent at 72 weeks) are FDA-approved, on formulary in most plans, and produce durable weight loss now. Switching to a next-generation drug at approval is straightforward.

VK2735 for Weight Loss: What Viking Therapeutics’ Dual GLP-1/GIP Pipeline Actually Looks Like in 2026

VK2735 is not FDA-approved and is not sold anywhere in the United States as of August 2026 — no legitimate pharmacy, telehealth clinic, or compounding operation can supply it. It is an investigational drug from Viking Therapeutics (San Diego, California), a small-molecule dual GLP-1 and GIP receptor agonist developed in parallel as a once-weekly subcutaneous injection (VK2735 SC) and a once-daily oral tablet (VK2735 oral). VK2735 activates the same two receptors as tirzepatide (Zepbound) but is being developed in both formulations at once — the only next-generation obesity candidate with that parallel-formulation strategy.

The headline data: the VENTURE-1 Phase 2 SC trial (Viking Therapeutics topline, March 2024) reported roughly 14.7 percent placebo-adjusted weight loss at 13 weeks at the 5 mg dose — the largest short-timeframe weight-loss signal ever reported for a Phase 2 obesity trial. For context, semaglutide reached roughly 6 percent and tirzepatide roughly 8 percent in equivalent 12-week windows. The 13-week timeframe is short, so what the 52-week Phase 3 magnitude will be is genuinely unknown.

This page explains what VK2735 is, what the VENTURE-1 data actually showed, how the parallel oral tablet program is progressing, how it compares to the rest of the next generation weight loss drugs pipeline, and the honest 2026 read for US patients — including why the earliest realistic SC availability is 2028 to 2029 and why any online product marketed as “VK2735” today is not the drug from the Viking trials.

What VK2735 is

VK2735 is a small-molecule non-peptide dual receptor agonist. It engineers two mechanisms into one chemical entity:

• GLP-1 receptor activation — the same receptor that Ozempic, Wegovy, Mounjaro, Zepbound, Rybelsus, and orforglipron activate. GLP-1 signalling drives satiety through the hypothalamic arcuate and paraventricular nuclei, delays gastric emptying, and improves insulin secretion.
• GIP receptor activation — the second incretin receptor that tirzepatide engages. Adding GIP agonism on top of GLP-1 is the mechanistic reason tirzepatide reaches roughly 21 percent weight loss versus roughly 15 percent for semaglutide.

The two features that make VK2735 distinctive in the 2026 pipeline are the non-peptide chemistry and the parallel injectable-plus-oral development plan. Tirzepatide is a peptide, injectable only. Orforglipron is a small-molecule oral but engages only a single receptor (GLP-1). VK2735 is the only pipeline drug developing a small-molecule GLP-1/GIP dual in both a weekly injectable and a daily oral tablet — every other post-tirzepatide next-generation asset is single-formulation.

Plain-English mechanism: VK2735 activates the same two receptors as tirzepatide (Zepbound) but is being developed in both an injectable and an oral form, aiming to give patients a choice between a weekly shot and a daily pill.

Dose and route — how VK2735 sits alongside tirzepatide and Rybelsus

VK2735 spans two formulations that will end up on very different parts of the pharmacy shelf. The table below sets the two VK2735 formulations against the closest existing comparators — the injectable multi-receptor incumbent (tirzepatide) and the currently-approved daily oral GLP-1 (Rybelsus).

The Rybelsus fasting-water rule matters here. Rybelsus depends on the SNAC absorption enhancer to survive the stomach at roughly 1 percent oral bioavailability, and the empty-stomach protocol is a real adherence obstacle in T2D real-world data. Because VK2735 oral is a non-peptide small molecule rather than a peptide plus SNAC, it may not need the same protocol — but that will not be known until Viking publishes the Phase 1 tablet PK data and the confirmed label instructions. Until then, the honest answer is “not confirmed — Phase 1 oral study is ongoing.”

VENTURE-1 Phase 2 SC obesity trial — the headline data

VK2735 SC is the more mature of the two formulations. The pivotal Phase 2 signal came from the VENTURE-1 trial, whose topline Viking Therapeutics reported in March 2024.

• Design: randomized, double-blind, placebo-controlled, dose-titration.
• Population: 176 adults with BMI ≥ 30, or ≥ 27 with at least one weight-related comorbidity.
• Duration: 13 weeks.
• Doses: 2.5 mg, 5 mg, 7.5 mg, 10 mg once-weekly subcutaneous.
• Primary endpoint: mean percent weight change from baseline to week 13.

The topline number that reset expectations: roughly −14.7 percent placebo-adjusted weight loss at the 5 mg dose at 13 weeks, with a clear dose-response from 2.5 mg → 5 mg. For context, both semaglutide and tirzepatide were used as comparator benchmarks in the same short-window territory:

The 14.7 percent at 13 weeks signal is the largest short-timeframe magnitude reported for any Phase 2 obesity trial to date. The important honest qualifier is that 13 weeks is short — the weight-loss curve had not plateaued, so the eventual 52-week Phase 3 number is genuinely unknown. It could land above tirzepatide’s 21 percent SURMOUNT-1 number, at it, or below it. That question is exactly what Phase 3 is designed to answer.

VENTURE-2 Phase 1 oral tablet program

The oral formulation is the more mechanistically novel half of the VK2735 story. Viking initiated the VENTURE-2 Phase 1 SAD/MAD oral tablet program in Q4 2024, with topline PK, pharmacodynamic, and preliminary weight-change data expected mid-2026.

Two things matter about the oral program:

• A small-molecule GLP-1/GIP dual in tablet form is a first. Every other dual agonist in development or approved is a peptide, and peptides are much harder to formulate as oral drugs (Rybelsus needs the SNAC absorption enhancer at roughly 1 percent bioavailability; the amycretin oral tablet is built on the same SNAC platform). A non-peptide small molecule can, in principle, hit tirzepatide-class magnitude without the SNAC constraint.
• A daily oral tirzepatide-class molecule would compete directly with orforglipron on the oral shelf. Orforglipron is single-receptor (GLP-1 only) with a Phase 3 ATTAIN-1 magnitude of roughly 12.4 percent at 72 weeks. A dual-receptor oral tablet could plausibly exceed that — if the Phase 1 oral PK translates to Phase 2 efficacy.

Honest disclaimer: the VENTURE-2 Phase 1 data are safety and pharmacokinetic, not efficacy. Any weight-change signal at the end of a Phase 1 tablet study is exploratory. Phase 2 oral efficacy readouts are 2027 at the earliest.

Mechanism — why dual GLP-1/GIP matters

Adding GIP receptor agonism on top of GLP-1 is the mechanistic story behind tirzepatide’s roughly 21 percent SURMOUNT-1 magnitude versus semaglutide’s roughly 15 percent STEP-1 magnitude. Frías JP et al. (NEJM 2018) is the foundational tirzepatide Phase 2 mechanism paper (SURPASS pre-Phase 3 dose-ranging), and Jastreboff AM et al. (NEJM 2022, SURMOUNT-1) is the Phase 3 obesity trial that established the dual-agonist superiority over placebo and, in cross-trial comparison, over semaglutide.

The mechanism is complementary rather than redundant. GLP-1 receptor activation drives satiety through hypothalamic circuits and delays gastric emptying. GIP receptor activation adds effects on adipose tissue lipid handling, food intake regulation via a different neural circuit, and — pharmacologically — attenuates some of the nausea burden that comes with high-dose GLP-1 monotherapy. The net effect at matched exposure is more weight loss with tolerability comparable to the single-receptor drug.

A small-molecule dual GLP-1/GIP molecule that also comes in an oral form is a commercially and clinically meaningful step. Commercially, the injectable multi-receptor market is dominated by two Lilly and Novo peptides today; a Viking-controlled small-molecule alternative changes the competitive landscape. Clinically, an oral dual agonist opens the pill option for the meaningful minority of patients who cannot or will not inject. For the full family view of the on-label class today, see the GLP-1 medications comparison.

Six-row pipeline comparison — VK2735 SC and oral vs the rest of the pipeline

The table below sets VK2735 SC and VK2735 oral against the four closest pipeline and standard-of-care comparators. Numbers are the highest reported Phase 2 or Phase 3 topline for each drug at the timeframes noted. Cross-trial comparisons across separate populations always overstate the certainty of the difference — the value here is the mechanism-and-magnitude map, not a ranked leaderboard.

VK2735 is the only pipeline drug developing a small-molecule GLP-1/GIP dual in both injectable and oral forms — every other post-tirzepatide asset is single-formulation. That mechanistic uniqueness, plus the strongest short-window Phase 2 signal in the entire pipeline, is why the drug is being watched despite trailing tirzepatide, orforglipron, and retatrutide on regulatory readiness.

Safety profile from Phase 2

The VENTURE-1 safety picture is a class-typical incretin tolerability profile at short exposure. The important caveats are the small sample size (n=176) and short window (13 weeks) — the class-defining long-term safety questions are all Phase 3 questions.

• Nausea — roughly 15 to 25 percent at the 5 mg dose, higher at 7.5 and 10 mg. Consistent with the GLP-1 class and comparable to early tirzepatide titration.
• Vomiting and diarrhea — single-digit to low-double-digit percent, titration-related, mostly during weeks 1 to 4.
• Transient LFT bump — a single-digit-percent subset of patients had a transient rise in liver-function tests during titration, reported in Viking’s Phase 2 briefing. The pattern was consistent with early-course GI-adaptive changes rather than hepatotoxicity, and resolved with continued dosing in most patients.
• Cardiac signal — no cardiac signal detected at 13 weeks. Heart rate was neutral (VK2735 does not activate the glucagon receptor, unlike survodutide or retatrutide, so a glucagon-arm heart-rate signal is not expected).
• Off-target signal — none reported in Phase 2 topline.

The class-defining safety questions require Phase 3 exposure to answer. Those questions are:

• Thyroid C-cell hyperplasia and medullary thyroid carcinoma (MTC) — the incretin class carries a boxed warning for this in rodent studies. The clinical human signal remains uncertain but any next-generation drug in this class will carry the MTC / MEN2 warning language.
• Pancreatitis — a class safety topic. Signal in Phase 3 is what matters.
• Gastroparesis and delayed gastric emptying — the class delays gastric emptying by design; the clinical severity spectrum is Phase 3 characterization.
• Long-term LFT trend — the Phase 2 transient bump should be tracked over 52 weeks or more of Phase 3 exposure.

Phase 3 timeline expectations

Viking Therapeutics has publicly guided VK2735 SC into a Phase 3 obesity program with enrolment starting late 2025 into 2026. The realistic reasoning on the timeline:

• Phase 3 SC enrolment — late 2025 / 2026.
• Phase 3 SC primary readout — 2027 to 2028 depending on trial length (52 weeks is the standard obesity endpoint; a longer cardiovascular outcomes study would push later).
• FDA submission — 2028 to 2029 for the SC form, assuming positive primary readout.
• FDA review — 10 to 18 months. Priority review would compress; standard review would land in 2029 to 2030.
• Earliest realistic SC availability on US pharmacy shelves — 2028 to 2029.
• Oral form — approximately two to three years behind the SC form on all of the above steps.

For comparison against the drugs closest to VK2735 in the pipeline:

• Orforglipron — Phase 3 ATTAIN-1 already reported; Lilly guidance is regulatory submission by mid-2026 window; realistic first-to-market oral GLP-1 in 2026 to 2027.
• Retatrutide — Phase 3 TRIUMPH enrolment complete for some arms; obesity readouts 2026 to 2027; earliest availability 2027 to 2028.
• Tirzepatide — already approved (Zepbound 2023 for obesity, Mounjaro 2022 for T2D); available today.

VK2735 SC lands in the 2028 to 2029 window at the earliest — behind orforglipron, retatrutide, CagriSema, and probably MariTide.

The commercial and licensing angle

Unlike Eli Lilly and Novo Nordisk, Viking Therapeutics is a small-cap NASDAQ biotech (approximate market capitalization in the roughly 5 to 15 billion dollar range as of 2026) without an in-house commercial infrastructure. That matters for patients because it means the path from Phase 3 success to a bottle on a US pharmacy shelf will go through one of two commercial routes:

• Big Pharma acquisition. Lilly, Novo Nordisk, Pfizer, Merck, and other large-pharma acquirers have been publicly discussed as prospective buyers of Viking or of the VK2735 program specifically. An acquisition typically triggers integration of the acquired asset into the acquirer’s commercial engine (manufacturing scale-up, contracted formulary access, PBM negotiation).
• Commercialization partnership. A licensing or co-development deal in which Viking retains partial economics while a larger partner runs Phase 3 completion, submission, and launch.

Which route Viking takes will be decided by 2027 Phase 3 readout timing and by any Big Pharma deal that follows. Whether VK2735 reaches patients as a Viking-branded product, a Lilly-branded product, or a co-marketed product will be decided by 2027 Phase 3 outcomes and any acquisition deal that follows — and that determines pricing, formulary placement, and prior-authorization pathways in 2028 to 2029.

For the current 2026 pricing landscape and Medicare Part D coverage picture that VK2735 will inherit, see GLP-1 cost and insurance.

What VK2735 does not do in 2026

The Phase 2 headline number is genuinely exciting, but the honest limits matter for any 2026 reader making a treatment decision.

• Not FDA-approved for any indication. No US access route exists.
• Not compoundable. VK2735 is a small-molecule non-peptide, has never been on the FDA drug-shortage list, and has no legitimate 503A or 503B compounding pathway even in an emergency shortage. Do not respond to any “compounded VK2735” grey-market vendor — the molecule is not manufacturable via the compounding-pharmacy pathway and any product sold under that name is mislabeled, an unrelated compound, or counterfeit. See compounded semaglutide and tirzepatide safety for the 2026 enforcement landscape.
• No head-to-head data against tirzepatide, orforglipron, retatrutide, or any next-generation pipeline drug. Every side-by-side comparison in this article and elsewhere is cross-trial.
• No cardiovascular outcomes trial (CVOT) yet. Viking has not initiated a dedicated CVOT for VK2735; a Phase 3 obesity program with a cardiovascular sub-study or a separate CVOT would be needed before any cardiovascular-risk-reduction indication analogous to Wegovy’s SELECT.
• No T2D indication yet. Viking’s diabetes program is a separate molecule; VK2735 has not filed for or been developed against a T2D primary endpoint.

Practical read for US patients in 2026

If you are choosing weight-loss pharmacotherapy today, VK2735 is not on the shelf and will not be for at least three years for the SC form and five or more years for the oral tablet. Wegovy and Zepbound are FDA-approved, produce durable weight loss (roughly 15 percent and 21 percent respectively at their pivotal 68- and 72-week endpoints), and switching to a next-generation drug at approval is straightforward: hold the current drug on the injection day, start the new drug at its starter dose the following week, and titrate. There is no clinical or economic reason to wait three years for a drug that may or may not be available at your pharmacy.

If you are tracking the biotech pipeline for a family member or a patient rather than choosing therapy today, the primary signal sources through 2026 and into 2027 are Viking Therapeutics’ quarterly conference calls (VENTURE-2 Phase 1 oral tablet mid-2026 topline is the near-term catalyst), Viking’s press releases, and ClinicalTrials.gov postings for VENTURE-3 and VENTURE-4 as the Phase 3 SC program stands up.

For the full 2026 map of pipeline drugs, mechanism trees, and the practical “should I wait?” protocol, see the next generation weight loss drugs pillar. For the on-label 2026 options that are actually on pharmacy shelves today, see prescription weight loss medications, semaglutide for weight loss, and tirzepatide for weight loss.