Mazdutide
Dual GLP-1 and glucagon receptor agonist · Xinermei in China. Development codes IBI362 and LY3305677
- UK status
- Not licensed in the UK
- Availability
- Licensed in China only
- Evidence base
- Human RCT, phase 3
- Controlled drug
- No
Sequence
A modified peptide based on glucagon. Sequence not published in a form worth reproducing.
The short version
What it does
Reduces appetite and body weight, and controls blood sugar. Approved for both in China.
How it does it
Copies your gut's after-meal fullness signal, and also activates a second hormone system that increases the rate you burn energy. Eat less and spend more.
The catch
It is a proper approved medicine, in China. Not here. An approval in one country does not transfer, and anything sold to a UK buyer as mazdutide is unlawful and unverifiable.
Everything below goes into the detail, with sources.
Mazdutide is the first drug in this register approved in China and nowhere else, and that makes it a useful test of what an approval actually tells you. It is real, it went through a real regulator, and none of that makes it available or lawful here.
At a glance
- Compound type
- Peptide, based on glucagon
- Drug class
- Dual glucagon and GLP-1 receptor agonist
- Originator
- Eli Lilly, licensed to Innovent Biologics for China
- Route
- Injection under the skin
- Frequency
- Weekly
- China approval
- June 2025 for weight management, September 2025 for type 2 diabetes
- UK, EU and US status
- Not approved. No UK filing publicly confirmed.
- Notable
- The first dual glucagon and GLP-1 agonist approved anywhere
- In sport
- Unapproved outside China, so would fall under WADA S0. Verify with UKAD.
01What it is
Mazdutide activates two receptors: GLP-1, and glucagon. Survodutide and retatrutide are betting on the same glucagon component, which raises blood glucose by design while also increasing energy expenditure and acting on liver fat.
What separates mazdutide is that it got to a market first. China's National Medical Products Administration approved it in June 2025, making it the world's first approved dual glucagon and GLP-1 receptor agonist.
Eli Lilly developed the molecule and licensed Chinese rights to Innovent Biologics in 2019. Lilly retains rights everywhere else, where it is not approved. So the same company that makes tirzepatide owns this outside China, which is worth knowing when reading about its prospects.
02How it came about
Early phase 1b trials in Chinese adults were published from 2021. The pivotal phase 3 GLORY-1 trial enrolled 610 Chinese adults with overweight or obesity, reporting mean weight reductions around 12 per cent at week 48 against placebo. GLORY-2, at a higher dose, reported larger figures over 60 weeks.
For type 2 diabetes, the DREAMS-1 and DREAMS-2 phase 3 trials reported superiority over placebo and over dulaglutide, leading to a second Chinese approval in September 2025. It is also under evaluation for fatty liver disease, obstructive sleep apnoea and alcohol use disorder.
03UK legal and licensing status
Mazdutide has no MHRA marketing authorisation and no EMA or FDA approval. It cannot lawfully be prescribed or supplied for human use in the UK, and no UK regulatory filing had been publicly confirmed as of mid-2026.
Its Chinese licence covers adults with a BMI of 28 or above, or 24 or above with at least one weight-related condition, alongside diet and activity. Those thresholds are lower than UK criteria, which reflects different population body composition rather than a looser standard.
Grey-market sellers sometimes present Chinese approval as evidence a compound is safe and effective, and it is evidence of exactly that in the population and at the doses the Chinese regulator assessed. It is not a UK licence, and it does not make an unverified vial from an online shop the studied product.
04How it works
- GLP-1 receptor. Reduced appetite, slower gastric emptying, glucose-dependent insulin release.
- Glucagon receptor. Increased energy expenditure, and direct effects on liver fat.
- Weekly injection.
05What it is not
Claims that attach themselves to this compound and do not hold up.
- Not licensed in the UK, the EU or the US. A Chinese approval does not transfer.
- Not verified by a UK regulator. There is no SPC, no MHRA-approved patient information and no Yellow Card coverage here.
- Not the studied product if bought online. The trials used a manufactured, assayed medicine. A grey-market vial is neither.
- Not directly comparable to Mounjaro. No head-to-head trial exists at weight-management doses.
06What the evidence shows
The evidence base is genuine phase 3 data, published in the New England Journal of Medicine among others, and it was sufficient for a national regulator.
The pivotal trials were conducted in Chinese populations. That is appropriate for a Chinese approval and it is a real constraint on generalising. Body composition, baseline BMI distribution and metabolic risk differ between populations, which is why regulators elsewhere want data relevant to their own.
DREAMS-2 beating dulaglutide is the more transferable finding, because a head-to-head against a drug licensed worldwide is easier to interpret than a placebo comparison.
No UK or EU assessment, so no SPC and no MHRA-approved patient information. No head-to-head against tirzepatide or semaglutide at weight-management doses. Long-term glucagon-receptor safety remains the open question across this sub-class.
07Reported harms
Trial reporting describes predominantly mild to moderate gastrointestinal effects, the class pattern. Chinese product information carries the authoritative frequency table; there is no UK SPC and no Yellow Card coverage here.
The glucagon component's effect on blood glucose is the mechanism-level concern, and is why cardiovascular and metabolic safety data matters for this whole sub-class.
08Interactions and cautions
No UK SPC to consult. The class cautions would be expected to apply, and the glucagon component makes combination with diabetes medication a genuine rather than theoretical unknown outside Chinese prescribing guidance.
09Stopping
Appetite suppression ends when the drug does, as across the class. Weight regain would be expected.
10Monitoring
In Chinese clinical use, a prescriber tracks weight, HbA1c and tolerability. Outside that, nobody is monitoring anything.
11Questions worth asking
Take these to a doctor or pharmacist. A good clinician will not mind being asked, and the answers are specific to you in a way nothing on this page can be.
- Is there any lawful route to this in the UK? (There is not, outside a trial.)
- If I am waiting for something better, does a licensed option make sense now?
- Do I understand that a Chinese approval gives me no UK protections at all?
12Common questions
Is mazdutide available in the UK?
No. It has no MHRA authorisation and no EMA or FDA approval. It is approved in China, marketed as Xinermei, and that approval does not transfer.
Is mazdutide as good as Mounjaro?
Unknown. There is no head-to-head trial at weight-management doses. Its phase 3 figures in Chinese populations are substantial but not directly comparable to trials run elsewhere in different populations.
Why is it approved in China but not here?
Its pivotal trials were conducted in Chinese populations and submitted to China's regulator. Regulators want data relevant to their own populations, and no UK filing has been publicly confirmed. Approval is jurisdiction by jurisdiction, not global.
Eli Lilly makes it, so will it come to the UK?
Lilly developed the molecule and holds rights outside China, where it is not approved. Whether it files in the UK is a commercial decision, and Lilly already sells tirzepatide here. Draw your own conclusions, but nothing has been announced.
13Sources
Links go to the authoritative source. Where a document sits behind a paywall or moves around, the full citation is given so you can find it yourself.
- Mazdutide first approval reviewDrugs, Springer, 2025
- Once-weekly mazdutide in Chinese adults with obesityNew England Journal of Medicine, 2025
- GLORY and DREAMS trial recordsClinicalTrials.gov
- Survodutide record/compounds/survodutide/
- Unlicensed medicines guidanceMHRA
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