Lower numbers = closer to natural. Higher numbers = more enhanced.
Why this rating?
Mazdutide is a dual GLP-1 / glucagon (GCG) receptor agonist based on the mammalian oxyntomodulin (OXM) scaffold. The GLP-1 arm suppresses appetite and improves glycemic control; the glucagon arm increases energy expenditure and improves hepatic fat metabolism. It works through satiety and metabolic-rate pathways, not anabolic ones, and does not affect testosterone or muscle building directly. Rated 3.5: slightly above the pure GLP-1s (3) because the glucagon arm makes it metabolically more aggressive, but below the triple agonist retatrutide (4).
Overview
A dual GLP-1 / glucagon (GCG) receptor agonist, notably developed and first approved in China (Innovent Biologics, co-developed with Eli Lilly). Built on the mammalian oxyntomodulin (OXM) peptide, it combines appetite suppression with increased energy expenditure and improved hepatic fat metabolism. In the pivotal GLORY-1 Phase 3 trial (n=610, 48 weeks), the 4mg and 6mg doses produced ~12% and ~15% weight loss respectively, and GLORY-2 showed up to ~20.1% weight loss at the 9mg dose in participants without diabetes.
Important Warnings
- •GLP-1-class agents are contraindicated with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia type 2 (MEN 2)
- •The glucagon component can increase heart rate and add glucose-management complexity. Monitor, especially in diabetics
- •Higher doses (9-16mg) meaningfully increase GI side effects and discontinuation
- •Rapid weight loss causes lean-mass (muscle) loss unless protein and resistance training are prioritized
- •Rebound weight gain is common after discontinuation without sustained lifestyle change
- •Do not stack with other GLP-1/GIP/glucagon agonists, additive GI, dehydration and muscle-loss risk
- •Approved in China only; not FDA-approved: Western long-term data is limited
Purpose & Use Cases
Weight Loss
GLORY-1 Phase 3 (n=610) showed ~12% weight loss at 4mg and ~15% at 6mg over 48 weeks; GLORY-2 showed up to ~20.1% at the 9mg dose. A Phase 2 dose-finding study (n=177, presented at ObesityWeek 2025) reached ~22.3% at 16mg over 48 weeks.
Type 2 Diabetes / Glycemic Control
Approved by China's NMPA for glycemic control; Phase 3 diabetes data (published in Nature) showed strong HbA1c reduction alongside weight loss.
Metabolic & Hepatic Health
Glucagon activity improves hepatic fat metabolism and energy expenditure; the GLORY-3 program studies mazdutide in overweight/obesity with fatty liver disease.
Benefits
- Strong weight loss (up to ~20% at 9mg; ~22% at 16mg in Phase 2)
- Dual mechanism adds energy expenditure and hepatic fat handling to appetite suppression
- First dual GCG/GLP-1 agonist approved for weight management (China NMPA)
- Once-weekly subcutaneous dosing
- Improves glycemic control, liver fat and other metabolic markers
Good to Know
Developed and first approved in China
Mazdutide (Innovent, co-developed with Eli Lilly) is the first dual GCG/GLP-1 agonist approved for weight management, cleared by China's NMPA in 2025 for both obesity and type 2 diabetes. It is not FDA-approved, so Western availability is via that regulatory route or research-chemical channels.
Oxyntomodulin-based, glucagon-inclusive
It is built on oxyntomodulin (OXM), a natural gut hormone that hits both GLP-1 and glucagon receptors. The glucagon arm adds energy expenditure and hepatic fat handling on top of appetite suppression, more metabolic aggression than a pure GLP-1, at the cost of a bit more heart-rate rise.
Dose scales hard with effect and side effects
Weight loss climbs with dose (~12% at 4mg, ~15% at 6mg, ~20% at 9mg, ~22% at 16mg in Phase 2) but so do nausea, vomiting and dropout. Approved weight-management strengths in China are 4mg and 6mg.
Lean-mass loss during rapid weight loss
As with all satiety agents, weight lost includes muscle if protein and training lapse. High protein plus resistance training is what protects lean tissue, important in a physique context.
No anabolic or hormonal action
Does not raise or suppress testosterone, does not aromatize, no HPTA effect. No AI and no PCT considerations apply: it is a metabolic tool.
Rebound weight is expected
Appetite and energy balance normalize after stopping; weight regain is the default without established diet and training habits.
Dosage Guidelines
| Experience Level | Dosage Range |
|---|---|
| Beginner | 2 – 4 mg/week |
| Intermediate | 4 – 6 mg/week |
| Advanced | 6 – 9 mg/week |
China approved the 4mg and 6mg strengths for weight management, reached via a stepwise titration: 2mg weekly to start, increasing to 4mg after 4 weeks, then optionally to 6mg after at least 4 more weeks. A 9mg strength (used in GLORY-2) is under NMPA review but not yet approved. Phase 2 dose-finding went as high as 16mg (~22.3% loss at 48 weeks) but with more nausea and discontinuation. Slow titration limits GI effects and the glucagon-driven heart-rate rise.
Reported estimates vary by source; the fatty-acid acylation extends the half-life enough to support once-weekly dosing.
Side Effects
Nausea
very commonThe dominant side effect during titration, from GLP-1-driven delayed gastric emptying; worse at higher doses.
Slow titration; smaller meals; avoid fatty foods.
Vomiting
commonMore likely at higher doses (9-16mg) and with rapid titration.
Slow titration; do not overeat.
Diarrhea
commonCommon GI disturbance during dose escalation.
Stay hydrated; slow titration.
Increased Heart Rate
commonGlucagon-receptor activation raised mean heart rate modestly at the approved 4-6mg doses (~2.6 bpm at week 48 in GLORY-1), with larger increases reported at higher investigational doses (9mg+), more than a pure GLP-1 agent.
Monitor heart rate; slow titration keeps it manageable for most.
Decreased Appetite
very commonExpected effect; can be excessive and lead to under-eating protein.
Prioritize protein; do not skip meals entirely.
Constipation
uncommonSlowed GI motility can cause constipation.
Fiber, hydration, movement.
General Mitigation Strategies
GI side effects are dose-dependent and ease with a slow, patient titration; higher doses (9-16mg) carry more nausea, vomiting and discontinuation. Monitor heart rate given the glucagon component. Keep protein high and train with resistance to protect lean mass during rapid loss. Stay hydrated. Discontinue and seek care for severe persistent abdominal pain (pancreatitis concern).
Support Supplements
Ancillary supplements commonly run alongside Mazdutide to manage side effects, support the target tissue, or fill nutrient demands it creates.
High Protein Intake
KeyStrong appetite suppression makes under-eating protein easy, which accelerates lean-mass loss. Adequate protein is the primary lever for preserving muscle during weight loss.
- Dose
- 1.6-2.2 g per kg bodyweight per day
- Timing
- Spread across meals; eat protein first when appetite is low
Resistance Training
KeyThe essential stimulus for retaining lean mass in a caloric deficit; without it a larger share of lost weight is muscle. A companion protocol, not a supplement.
- Timing
- 2-4 sessions per week, progressive overload
Creatine Monohydrate
Supports strength and lean-mass retention during a deficit; well-evidenced and inexpensive.
- Dose
- 3-5 g daily
- Timing
- Any time, daily and consistent
Electrolytes & Hydration
GI losses and reduced intake can cause dehydration and electrolyte depletion; supports the glucagon-related heart-rate response and kidney protection.
- Dose
- Sodium/potassium/magnesium to appetite; deliberate fluid intake
- Timing
- Daily, more around GI episodes
Post Cycle Therapy (PCT)
Not anabolic-hormonal. Does not affect the HPTA. No PCT required. Maintain diet and training habits to limit weight regain after stopping.
How It Works
Mazdutide is an acylated analog of oxyntomodulin (OXM), a gut hormone that naturally activates both the GLP-1 and glucagon receptors. GLP-1 agonism suppresses appetite, slows gastric emptying, drives glucose-dependent insulin secretion and improves glycemic control. Glucagon-receptor agonism increases resting energy expenditure and enhances hepatic lipid metabolism, which can raise the total metabolic effect and improve liver fat, but can also modestly increase heart rate. Fatty-acid acylation extends its half-life to support once-weekly subcutaneous injection.
Fundamentals
Reference on the practices relevant to Mazdutide: how they are done and where they go wrong. Not a recommendation to use it.
Legal Status
Approved in China. China's NMPA approved mazdutide for chronic weight management (June 2025) and glycemic control in type 2 diabetes (September 2025). Not FDA-approved. Developed by Innovent Biologics, co-developed with Eli Lilly.
Legal status varies by country and changes over time. This is a general summary, not legal advice.
WADA Status
Mazdutide is not listed on the WADA Prohibited List. GLP-1-class weight agents were added to WADA's Monitoring Program in 2025 (not banned), with the monitoring data expected to inform a Prohibited List decision before the 2028 Los Angeles Olympics. Verify current status before competition.