What Is UBT251?

1. What is UBT251 and how does it work?

UBT251 is described by its developer as a long-acting synthetic peptide triple agonist of the GLP-1, GIP and glucagon receptors, with potent activity at all three in preclinical studies. In China it is classified as a Class 1 innovative drug (licensing announcement).

Each receptor contributes something different:

• GLP-1 reduces appetite, slows stomach emptying and raises insulin after meals, the effect behind semaglutide.
• GIP is the second incretin hormone. Combined with GLP-1, it underpins tirzepatide.
• Glucagon increases energy use and fat burning in the liver. On its own it raises blood sugar, so triple agonists rely on GLP-1 and GIP to offset that.

The published papers do not disclose UBT251’s full structure or its relative potency at each receptor, which is the main way triple agonists differ from one another. A Phase 1 study found roughly linear pharmacokinetics across 1 to 6 mg after single and repeated doses, consistent with weekly dosing (Yang et al., Diabetes Obes Metab 2026).

2. What is the Novo Nordisk deal?

On March 24, 2025, United Biotechnology and Novo Nordisk signed an exclusive license. Novo received worldwide rights except in mainland China, Hong Kong, Macau and Taiwan, where United Biotechnology kept the rights. United Biotechnology received $200 million upfront, with eligibility for up to $1.8 billion in milestones and tiered royalties on sales in Novo’s territory (licensing announcement).

At signing, UBT251 had trial approvals in China for type 2 diabetes, overweight or obesity, MAFLD (fatty liver disease) and chronic kidney disease, and in the United States for type 2 diabetes, overweight or obesity and chronic kidney disease. Novo’s development head, Martin Holst Lange, said it “will add important optionality to our clinical pipeline.”

The first milestone arrived on July 15, 2026, when United Biotechnology received $13.5 million from Novo for a global Phase 2 trial of UBT251 in overweight or obesity (TUL announcement, July 2026).

3. What did the Phase 1 study show?

The first-in-human study combined a single-dose part (0.1 to 4.5 mg) and a 12-week multiple-dose part in Chinese adults with overweight or obesity but no diabetes. Weekly doses of 1, 3 and 6 mg produced mean weight reductions of 8.96 to 13.48 kg, against a 1.57 kg gain on placebo. UBT251 also lowered fasting glucose, HbA1c and blood lipids. The most common adverse effects were laboratory changes, decreased appetite and gastrointestinal events (Yang et al. 2026).

The licensing announcement gave the same trial’s headline in percentage terms: 36 participants in three dose groups, titrated weekly for 12 weeks, and an average 15.1% weight loss among completers in the highest dose group, versus a 1.5% gain on placebo. Most adverse events were gastrointestinal and mild to moderate (licensing announcement). A completer figure counts only people who finished the trial, which usually flatters the result.

4. What did the Phase 2 obesity trial show?

The Phase 2 obesity trial (NCT07177469) enrolled 205 Chinese adults with overweight or obesity and without type 2 diabetes. They were 59.0% women, aged 18 to 61. Entry required a BMI of at least 28, or 24 to under 28 with a weight-related condition such as prediabetes, high blood pressure, abnormal lipids, fatty liver, joint pain or sleep apnea (registry). Those thresholds are lower than the BMI of 30 that defines obesity in most Western trials.

Participants took weekly UBT251 or placebo for 24 weeks. The arms were 2 mg, 4 mg reached from a 0.5 mg starting dose, 4 mg reached from a 1 mg starting dose, and 6 mg, each escalated every four weeks (registry; Zhou et al., Cell Metab 2026).

All UBT251 arms beat placebo by a wide margin. Least-squares mean weight change ranged from -13.6% to -19.7% on UBT251 versus -2.0% on placebo, placebo-adjusted differences of -11.5 to -17.7 percentage points. UBT251 also improved waist circumference, BMI, blood pressure, lipids and blood sugar measures. The most frequent adverse events were mild-to-moderate gastrointestinal symptoms, and the authors concluded the results support Phase 3 (Zhou et al., Cell Metab 2026).

Novo’s chief scientific officer described the results as suggesting a “differentiated” clinical, safety and tolerability profile, and Novo said the vast majority of gastrointestinal side effects were mild to moderate and faded over time (BioPharma Dive, February 2026).

Two cautions. Twenty-four weeks is short for an obesity drug, so the final plateau is unknown. And the trial enrolled only Chinese adults at a lower average BMI threshold than Western trials, so results may differ elsewhere.

5. What did the Phase 2 diabetes trial show?

The type 2 diabetes trial (NCT07163624) enrolled 211 Chinese adults (mean age 48.4, 131 men) with HbA1c of 7.0% to 10.5% on lifestyle measures or stable metformin. It used the same four UBT251 arms plus two comparators: placebo and semaglutide 1 mg (Ozempic) (registry).

Sources: Zhou et al., Cell Metab 2026; weight figures from Zacks, March 2026. Baseline HbA1c averaged 8.12%.

UBT251 also lowered fasting glucose, two-hour after-meal glucose and waist circumference more than placebo, and weight loss was significantly greater than with both placebo and semaglutide. Gastrointestinal events were the most common side effects (Zhou et al. 2026). The semaglutide arm used the 1 mg diabetes dose, not the 2 mg Ozempic or 2.4 mg Wegovy doses, so this was not a comparison against semaglutide at its strongest.

6. Where is UBT251 in development now?

UBT251 is moving on two tracks. A ClinicalTrials.gov search on November 8, 2026 lists 14 trials.

United Biotechnology’s program in China

A second sleep apnea Phase 3 in people using PAP therapy is also registered (NCT07806851). The obesity Phase 3’s primary outcome is body weight at week 52 (NCT07648225).

The other Chinese trials show where United Biotechnology hopes to take the drug beyond weight:

• Type 2 diabetes. Both UNIGUIDE trials measure HbA1c at week 40. UNIGUIDE-1 compares 2, 4 and 6 mg with placebo in people not on diabetes medicines (NCT07659574). UNIGUIDE-2 compares the same doses with semaglutide 1 mg in people already on metformin, with or without a sulfonylurea or SGLT2 inhibitor, and has the largest enrollment of any UBT251 trial (NCT07653477).
• Sleep apnea. The two sleep apnea Phase 3 trials, one in people using PAP therapy and one without, measure change in the apnea-hypopnea index (the number of breathing pauses per hour of sleep) at week 52 (NCT07767942).
• Liver. The MASH trial uses the standard biopsy endpoint, MASH resolution without worsening of fibrosis, at week 48 (NCT07145151).
• Kidney. The chronic kidney disease trial’s primary outcome is the urine albumin-to-creatinine ratio (UACR), a marker of kidney damage, at 24 weeks, with 2, 4 and 6 mg arms (NCT07134335).

Timeline

Sources: licensing announcement; NCT07177469; NCT07163624; BioPharma Dive; NCT07395687; NCT07668388; TUL announcement; NCT07648225; Zhou et al. obesity; Zhou et al. diabetes.

Novo Nordisk’s global program

Novo is also running drug-interaction studies, including one with oral contraceptives and stomach emptying (NCT07710729). Novo expects initial data from its global Phase 1b/2a obesity study in 2027 (BioPharma Dive; Zacks). A global Phase 3 has not been registered. If the Chinese Phase 3 succeeds, China is the most likely first market, since United Biotechnology holds the rights there and its trials are furthest along.

7. How does UBT251 compare with retatrutide and other triple agonists?

The retatrutide 24-week figure is from BioPharma Dive’s summary of Lilly’s Phase 2 trial (BioPharma Dive). The same article noted that Lilly is ahead in bringing a triple agonist to market, and that a retatrutide Phase 3 trial reported up to 29% weight loss in December 2025.

Retatrutide also has liver data: in its Phase 2 substudy, liver fat fell up to 82.4% at 24 weeks (Sanyal et al., Nat Med 2024). UBT251’s MASH trial is still recruiting. Efocipegtrutide, Hanmi’s triple agonist, is being developed mainly for MASH rather than weight. Separate trials cannot establish which drug works better; populations, durations and analysis methods differ.

Within Novo’s own pipeline, UBT251 sits alongside CagriSema, which combines semaglutide with the amylin analog cagrilintide, and amycretin, a GLP-1/amylin molecule.

8. What does UBT251 mean for people on GLP-1 therapy?

It is not a drug you can switch to. UBT251 exists only in clinical trials. A semaglutide or tirzepatide user cannot legally get it outside a trial, and gray-market “triple agonist” products are unverified.

Side effects should look familiar. The published trials report mainly mild-to-moderate gastrointestinal events, as with every GLP-1-based drug. Novo said these faded over time. Dose escalation every four weeks was used in all Phase 2 arms; the dose titration guide explains why.

Glucagon raises specific questions. Glucagon on its own raises blood sugar, and triple agonists depend on GLP-1 and GIP to outweigh that. The Phase 2 diabetes trial showed strong glucose lowering overall, but long-term cardiovascular safety data for UBT251, including heart rhythm and blood pressure over years, do not yet exist.

Muscle and body composition are not yet reported. Large and fast weight loss raises the question of how much lean mass is lost. No body-composition results for UBT251 have been published. The evidence on GLP-1 drugs and muscle loss is the best guide for now.

Expect a long wait outside China. Novo’s global program is at Phase 2, with first obesity data expected in 2027. A US or European approval would follow a Phase 3 program that has not yet been registered.

9. UBT251 FAQ

• Who makes UBT251?

  It was discovered and is developed in China by The United Bio-Technology (Hengqin) Co., a wholly owned subsidiary of The United Laboratories International Holdings (TUL), listed in Hong Kong. Novo Nordisk holds exclusive rights everywhere except mainland China, Hong Kong, Macau and Taiwan, where United Biotechnology keeps the rights.

• How much weight loss does UBT251 cause?

  In the 24-week Phase 2 trial in Chinese adults with overweight or obesity, least-squares mean weight change ranged from -13.6% to -19.7% across UBT251 doses versus -2.0% on placebo. That is 11.5 to 17.7 percentage points more than placebo. The trial was short and run only in China.

• Is UBT251 better than retatrutide?

  Unknown. Both are GLP-1/GIP/glucagon triple agonists, but no head-to-head trial exists. Retatrutide's earlier Phase 2 trial reported up to 17.5% weight loss at 24 weeks, a similar range to UBT251's 24-week result, but the two trials enrolled different populations. Retatrutide is further ahead, with Phase 3 results already reported.

• Is UBT251 approved?

  No. As of November 8, 2026, it is in Phase 3 in China and Phase 2 in Novo Nordisk's global program. No country has approved it, and no filing has been announced.

• What are the side effects of UBT251?

  In the published trials, the most common adverse events were gastrointestinal, such as nausea, mostly mild to moderate, along with decreased appetite and laboratory changes in the Phase 1 study. Detailed per-dose rates are in the Cell Metabolism papers. Because UBT251 includes glucagon activity, heart rate and blood sugar are among the class questions that larger trials will need to address.

• Why did Novo Nordisk license UBT251?

  Novo's development chief said in March 2025 that UBT251 would add important optionality to its clinical pipeline. It gives Novo a GLP-1/GIP/glucagon triple agonist, the same class as Eli Lilly's retatrutide, alongside its own semaglutide, CagriSema and amycretin programs.

• When could UBT251 be available?

  No date has been announced. The Chinese obesity Phase 3 trial has an estimated primary completion of September 2027, and Novo Nordisk expects initial global Phase 1b/2a obesity data in 2027. Any approval would come after those results and a regulatory review.

10. Sources