UBT251 is an investigational once-weekly GLP-1/GIP/glucagon triple agonist peptide. What the 2026 Cell Metabolism phase 2 obesity and type 2 diabetes trials showed, and what they don't.
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What Is UBT251?
UBT251 is an investigational peptide that activates three hormone receptors at once: GLP-1, GIP and glucagon. That puts it in the same "triple agonist" class as Lilly's retatrutide. It is given as a once-weekly subcutaneous injection in trials.
The registered sponsor of its trials is The United Bio-Technology (Hengqin) Co., Ltd., a company in China. Novo Nordisk employees are listed as co-authors on both 2026 phase 2 papers, which signals Novo's involvement in the program.
UBT251 is not approved by FDA or any other regulator we found. The phase 2 authors say their results support phase 3 evaluation, which means more testing, not approval. This page explains the research. It is not dosing guidance.
If you searched for "UBT251" after seeing a weight-loss chart on social media, read the section on cross-trial comparisons before anything else.
How a Triple Agonist Works, in Plain Terms
GLP-1 signalling reduces appetite and slows stomach emptying. Semaglutide works here.
GIP is a second gut hormone. Adding it to GLP-1 is the idea behind tirzepatide.
Glucagon receptor activity is thought to raise energy use and affect liver fat. Adding it is what makes a drug "triple."
That is the design logic. Whether a given molecule delivers each effect in people has to be shown in trials. For a side-by-side of the approved and late-stage drugs in this family, see our semaglutide vs tirzepatide vs retatrutide mechanisms guide.
The Evidence So Far
UBT251 has three published human studies. All were run in China.
Study
Who
Design
Main finding
Phase 1a/1b (Diabetes Obes Metab, 2026)
Healthy volunteers, then adults with overweight or obesity
Single and multiple ascending dose, placebo-controlled, 12 weeks in the obesity part
Safety and tolerability were the primary endpoints; GI events and decreased appetite were the most common adverse effects
Phase 2 obesity (Cell Metab, Oct 2026)
205 adults with overweight or obesity, without type 2 diabetes
Randomized, double-blind, placebo only, 24 weeks
Body weight fell 13.6% to 19.7% vs 2.0% with placebo
Phase 2 type 2 diabetes (Cell Metab, Oct 2026)
211 adults with type 2 diabetes
Randomized, double-blind, placebo and semaglutide 1 mg arms, 24 weeks
HbA1c fell 1.98 to 2.16 points vs 1.77 with semaglutide and 0.66 with placebo
Phase 2 obesity trial (NCT07177469)
The trial enrolled 205 adults (59% women) at multiple centres in China. Nobody had type 2 diabetes. Participants were randomized to one of four UBT251 regimens or placebo for 24 weeks. The primary endpoint was the percentage change in body weight at week 24.
Results, as published:
Least-squares mean weight change ranged from -13.6% to -19.7% across UBT251 arms, versus -2.0% with placebo.
Placebo-adjusted differences ranged from -11.5% to -17.7% (all p < 0.001).
The paper reports improvements in waist circumference, BMI, blood pressure, lipids and glucose measures. We have not reproduced those values here; read the paper for the exact figures.
The most frequent adverse events were mild-to-moderate gastrointestinal symptoms.
Three things to keep in mind when you read those numbers:
24 weeks is short. Retatrutide, tirzepatide and semaglutide trials usually report their headline results at 48 to 72 weeks. Weight was very likely still falling at week 24.
The arms were small. 205 people were split across four UBT251 regimens and placebo, so each arm's average is imprecise. The results are reported as a range across arms; read the paper for which regimen produced which number.
There was no active comparator. This trial compared UBT251 only against placebo.
This is a separate trial in a different population. It enrolled 211 Chinese adults with type 2 diabetes (mean age 48.4). Arms were four UBT251 regimens, semaglutide 1 mg, or placebo, for 24 weeks. The primary endpoint was the change in HbA1c.
HbA1c fell 1.98 to 2.16 percentage points with UBT251, versus 1.77 with semaglutide and 0.66 with placebo.
Fasting glucose, post-meal glucose and waist circumference fell more than with placebo.
The authors report that weight loss with UBT251 was greater than with both placebo and semaglutide (p < 0.05). This is the only head-to-head data against an approved drug. It was in people with diabetes, at the 1 mg semaglutide dose, over 24 weeks.
Gastrointestinal events were the most common adverse events.
Don't merge the two trials. The 13.6% to 19.7% weight-loss range comes from people without diabetes. In other incretin programs, people with type 2 diabetes have tended to lose less weight than people without it, so the two trials' weight results are not interchangeable.
Why You Can't Rank UBT251 Against Retatrutide
Social posts often put UBT251's top number next to retatrutide's phase 2 number. That comparison doesn't hold up:
UBT251 phase 2 obesity
Retatrutide phase 2 obesity
Population
205 adults in China, no diabetes
338 adults in the US, no diabetes
Primary timepoint
24 weeks
24 weeks (48-week result was secondary)
Comparator
Placebo
Placebo
Headline
-19.7% top arm mean at 24 weeks
-17.5% at 24 weeks and -24.2% at 48 weeks in the top arm
Different countries, populations, baseline weights, dose schedules and trial sites all affect results. Neither trial included the other drug. The only fair conclusion is that both produced large placebo-adjusted weight loss in phase 2. Whether one is better can only be answered by a head-to-head trial, and none exists.
Durability. No published data beyond 24 weeks in phase 2.
Body composition. The published abstracts don't report DXA lean-mass results. We don't know how much of the weight lost was fat versus lean tissue.
Diverse populations. All published trials ran in China.
Long-term safety. Six months of data can't show rare or slow-developing effects. Longer, larger trials are needed, including a close look at heart rate, which has risen with other drugs in this class.
Phase 3 timing and regulatory plans. The authors recommend phase 3. We did not find a registered UBT251 phase 3 trial or a filing with FDA when we checked.
Is UBT251 Available?
No. UBT251 is an investigational drug available only inside clinical trials. Anything sold online as "UBT251" is not the trial product, and there is no approved label, dose or quality standard for it. If you are thinking about weight-loss medicine, approved GLP-1 options exist. Talk with a licensed clinician about those.
Track What You Actually Take
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Frequently Asked Questions
Q: What is UBT251?
A: UBT251 is an investigational once-weekly peptide that activates GLP-1, GIP and glucagon receptors. Its trials are sponsored by The United Bio-Technology (Hengqin) Co., Ltd.
Q: Is UBT251 FDA approved?
A: No. It has completed phase 2 trials in China. The authors say the results support phase 3, which is a further testing stage.
Q: How much weight did people lose on UBT251?
A: In the 24-week obesity trial, average weight change was -13.6% to -19.7% across UBT251 arms, versus -2.0% with placebo. Results varied by dose arm and are group averages.
Q: Is UBT251 better than retatrutide?
A: That can't be determined. They have never been compared in the same trial, and their phase 2 trials enrolled different populations.
Q: Was UBT251 compared with semaglutide?
A: Yes, in the separate type 2 diabetes trial. UBT251 lowered HbA1c by 1.98 to 2.16 points versus 1.77 for semaglutide 1 mg, and weight loss was greater than with semaglutide.
Q: Is UBT251 a peptide?
A: Yes. The phase 1 paper describes it as a triple agonist peptide.
This article is educational content from PeptIQ. It is not medical advice. Talk with a licensed clinician before starting, stopping, or changing any peptide, medication, or injection practice.
