UBT251

In plain English

UBT251 (also UBT-251) is a once-weekly injection that switches on three receptors at once. GLP-1 and GIP reduce appetite and help control blood sugar, and glucagon is thought to raise energy use. Eli Lilly's retatrutide acts on the same three targets. The United Laboratories, a drug company based in Zhuhai, China, discovered UBT251, and Novo Nordisk holds exclusive rights everywhere except mainland China, Hong Kong, Macau and Taiwan under a license announced on March 24, 2025.

Two phase 2 trials were published in Cell Metabolism in October 2026, both in Chinese adults and both lasting 24 weeks. In the obesity trial, 205 adults without type 2 diabetes lost an average of 13.6% to 19.7% of their body weight on the four UBT251 groups, versus 2.0% on placebo. The abstract does not say which group lost how much.

In the type 2 diabetes trial, 211 adults received UBT251, semaglutide 1 mg or placebo. HbA1c, a blood sugar measure, fell by 1.98% to 2.16% on UBT251, by 1.77% on semaglutide and by 0.66% on placebo. The authors report greater weight loss on UBT251 than on either comparison. The abstract does not say whether the HbA1c gap against semaglutide was statistically significant, and a phase 2 trial is not a designed head-to-head test. A phase 3 trial against semaglutide, UNIGUIDE-2 (956 people), began recruiting in China in September 2026.

UBT251 is not approved anywhere. Phase 3 trials are registered in China for type 2 diabetes (recruiting), obesity and obstructive sleep apnea (not yet recruiting), and Novo Nordisk is running phase 2 trials in obesity and type 2 diabetes outside China. Results for each group, dropout rates and rates of individual side effects sit in the full papers, which the Atlas has not read.

Further reading

Two PeptideBlog.net write-ups cover UBT251 in more detail: the UBT251 entry, with the full trial registry table, and a news post on the two Cell Metabolism papers.

Two educational articles from another website look at UBT251 from a research angle: UBT251 compared with retatrutide and an overview of the obesity pipeline. Neither is peer reviewed.

Brand names and products

A generic name identifies the drug itself. A brand name identifies one company's product. One drug can come in several products with different forms and approved uses, so the brand name often tells you more about what a prescription is for.

No brand name is recorded for this medicine because there is no approved product.

How it works

UBT251 is a single molecule built to activate three receptors the body uses around meals. GLP-1 and GIP signals reduce appetite and prompt the pancreas to release insulin when blood sugar rises. Glucagon is better known for raising blood sugar, but it also increases energy use. The aim of adding it is more weight loss than a GLP-1 drug alone gives, and whether three signals beat two in practice is what the phase 3 trials are set up to test. The molecule's structure, receptor strength and half-life have not been published in the sources the Atlas reviewed.

Forms and approval status

What the trials found

These are group averages from published trials in adults without diabetes unless stated. See how to read trial numbers before comparing.

Safety

Boxed warning and label notes

• UBT251 injection (investigational): Not applicable. Not approved.

Warnings labels describe

• Not approved, so no official label exists. Safety information comes from two phase 2 papers and trial registry records.
• Both phase 2 trials lasted 24 weeks and enrolled Chinese adults only, so longer-term safety and results in other populations are unknown.
• Both phase 2 trials were run by the developer, and employees of the developer and of Novo Nordisk are among the authors.

Quick answers

What is UBT251?

UBT251 (also UBT-251) is an investigational once-weekly injection that activates the GLP-1, GIP and glucagon receptors. It is being studied for obesity and type 2 diabetes and is not approved anywhere.

Is UBT251 the same as retatrutide?

No. Both act on the GLP-1, GIP and glucagon receptors, but they are different molecules from different companies. Retatrutide is Eli Lilly's and is in phase 3. No trial has compared the two.

Who is developing UBT251?

The United Laboratories, a Chinese company, discovered it, and its subsidiary The United Bio-Technology (Hengqin) runs the China program. Novo Nordisk holds exclusive rights outside mainland China, Hong Kong, Macau and Taiwan under a license announced on March 24, 2025.

How much weight did people lose in the UBT251 trials?

In the 24-week phase 2 obesity trial, average weight change was -13.6% to -19.7% across the four UBT251 groups and -2.0% on placebo. These are group averages in Chinese adults. In the type 2 diabetes trial the authors report greater weight loss on UBT251 than on placebo or semaglutide 1 mg, without a figure in the abstract.

How does UBT251 compare with semaglutide?

In the 211-person type 2 diabetes trial, HbA1c fell by 1.98% to 2.16% on UBT251 and by 1.77% on semaglutide 1 mg. It was a phase 2 trial, so the formal comparison is the phase 3 trial UNIGUIDE-2, which has not reported.

What amounts of UBT251 were studied?

The phase 2 trials used 2 mg, 4 mg and 6 mg once weekly, with the 4 mg group reached from either a 0.5 mg or a 1 mg starting amount, for 24 weeks. These are trial amounts, not a recommendation, and there is no approved dose.

Is UBT251 approved?

No. It is not approved by any regulator. Phase 3 trials are registered in China, and the first registered primary completions are in September 2027.

What is still unknown

• Which amount produced which result. The abstracts give ranges across the four groups.
• Rates of nausea, vomiting and diarrhea, and how many people stopped treatment because of side effects.
• Results outside China and beyond 24 weeks. Novo Nordisk's phase 2 trials are the first source, with the first registered primary completion in January 2027.
• Phase 3 results. The first registered primary completions run from September 2027.
• How it compares with retatrutide or tirzepatide. No head-to-head trial exists.
• The molecule's structure, receptor strength and half-life, which the developer has not published.

Related medicines

Compare UBT251 with other medicines

Open the comparison tool with UBT251 selected. It puts forms, brand names, approval status and trial figures in one table. The figures come from different studies, so they are not head-to-head results unless the table says so.