Library / Peptides / Weight Management / Mazdutide

Emerging evidence · Grade B

Mazdutide

Mazdutide (LY3305677 / IBI362)

Evidence

Emerging

Route

Subcutaneous injection

Frequency

Once weekly

Mechanism.

Mazdutide is a novel dual GLP-1 and glucagon receptor agonist developed by Innovent Biologics (in partnership with Eli Lilly). It is designed to combine the appetite-suppressing and glucose-lowering effects of GLP-1 receptor agonism with the energy expenditure-boosting and lipolytic effects of glucagon receptor agonism. Phase 3 clinical trials have demonstrated significant weight loss, and it received its first approval in China in 2024 for chronic weight management in adults with obesity.

Semaglutide works by telling your body to eat less and absorb food more slowly. Mazdutide does that same thing (GLP-1) but also presses the accelerator on your metabolism (glucagon), telling your body to burn more fat and generate more heat — it's like dieting and boosting your metabolism at the same time.

Mechanism · technical

Mazdutide simultaneously activates two receptors: the GLP-1 receptor, which reduces appetite, slows gastric emptying, and improves insulin secretion; and the glucagon receptor, which promotes hepatic glycogenolysis, increases energy expenditure, and enhances lipolysis (fat breakdown). The glucagon component differentiates mazdutide from pure GLP-1 agonists like semaglutide by adding a thermogenic and fat-mobilizing effect. The dual mechanism aims to produce greater weight loss than GLP-1 agonism alone.

Part 02 · Dosing & administration

How it's taken.

Values below describe how Mazdutide has been administered in published trials and labeling. Provided for educational purposes only — this is not medical advice and not instructions for self-administration. Consult your healthcare provider before making any health decision.

Standard dose

3-6 mg (target dose after titration)

Subcutaneous injection · Once weekly

Duration

Ongoing as prescribed

GLP-1/glucagon receptor dual agonist. Approved in China (2024) for T2DM. Not yet FDA-approved. Titration schedule required to mitigate GI side effects.

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Part 03 · Safety

Side effects, rare serious events, who shouldn't.

Reported side effects

The most common side effects are gastrointestinal: nausea, vomiting, diarrhea, and decreased appetite — similar to other GLP-1 receptor agonists but potentially with additional effects from glucagon activation. Transient increases in heart rate have been observed. The glucagon component may cause mild hyperglycemia in some patients, though this is generally offset by the GLP-1 component. Injection site reactions can occur.

Absolute · do not use

Personal or family history of medullary thyroid carcinoma

Multiple endocrine neoplasia syndrome type 2 (MEN2)

Pregnancy or breastfeeding

Children under 18

Known hypersensitivity to mazdutide or any component

History of pancreatitis

Severe gastrointestinal disease (gastroparesis)

Interactions

Insulin

Increased risk of hypoglycemia; dose adjustment of insulin likely required

Major

Sulfonylureas

Additive hypoglycemic effect; dose reduction may be necessary

Major

Oral medications with narrow therapeutic index (warfarin, levothyroxine, oral contraceptives)

GLP-1/glucagon dual agonism delays gastric emptying, potentially altering absorption of oral medications

Moderate

Other GLP-1 receptor agonists

Additive GI and pancreatic effects; should not be combined

Major

Labs to monitor

HbA1c

Baseline and every 3 months

GLP-1/glucagon dual agonist — monitor glycemic control

Fasting Glucose & Insulin

Baseline and monthly

Track glucose homeostasis

Lipase & Amylase

Baseline and every 3 months

Pancreatitis screening (GLP-1 class concern)

CMP (Comprehensive Metabolic Panel)

Baseline and every 3 months

Liver and kidney function

Lipid Panel

Baseline and every 3 months

Glucagon component may affect lipid metabolism

Thyroid Panel (TSH, Free T4)

Baseline and every 6 months

GLP-1 class thyroid C-cell concern

Part 04 · Research log

Every study we cite.

Each study with its published finding and a plain-language note on limitations or funding.

2024

Mazdutide phase 3 for obesity in China

Mazdutide 6 mg achieved ~15% weight loss at 48 weeks vs placebo

Phase 3 RCT; industry-sponsored; Chinese population

2023

Mazdutide for type 2 diabetes: phase 3

Significant HbA1c reduction and weight loss in T2DM patients

Phase 3; industry-sponsored

Part 05 · Cost & access

Where you can get it.

Regulatory status

Mazdutide received its first regulatory approval from China's NMPA in 2024 for chronic weight management in adults with obesity (BMI >= 28 or >= 24 with comorbidities). As of early 2026, it is not yet FDA-approved in the United States. Phase 3 trials are ongoing globally, including studies for type 2 diabetes.

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Part 06 · Your appointment

Questions to bring.

How does mazdutide compare to semaglutide or tirzepatide for my weight loss goals?

What are the unique risks of glucagon receptor activation in addition to GLP-1?

Is mazdutide available in my country, or is it still in clinical trials here?

What GI side effects should I expect, and how do they compare to other GLP-1 drugs?

How will mazdutide affect my blood sugar if I have diabetes?

What monitoring (liver function, lipids, glucose) is recommended during treatment?