Peptide

Mazdutide

Also known as

IBI362 · IBI-362 · LY3305677 · LY-3305677 · OXM3 (development / oxyntomodulin-analog discussions) · Xinermei · 信诺美 (China brand name) · GLP-1/glucagon dual agonist · GCG/GLP-1 dual agonist · mazdutide peptide · Mezdutide (common misspelling in dose lists)

Community talk. May contain inaccuracies. Not medical advice. Not a protocol. Not for human or animal use.

What it is

GLP-1/glucagon peptide	An injected oxyntomodulin-like peptide, also called IBI362 or LY3305677, discussed for hunger control and weight loss.
Different from Tirz or Reta	Tirzepatide targets GLP-1/GIP; Retatrutide adds glucagon. Combining Mazdutide with Tirzepatide does not make an equivalent triple-agonist product.

Notes

Mazdutide is an injected GLP-1/glucagon peptide discussed for appetite, weight loss and extra energy. Some reports describe stronger hunger control than previous incretins; others describe sleepiness, nausea or unwanted mood changes. Trial results and personal experience answer different questions.

One peptide activates two receptors. Also called IBI362 or LY3305677, it mimics oxyntomodulin, a gut hormone. The GLP-1 side helps regulate hunger and glucose; the glucagon side is studied for additional metabolic effects. Feeling energized does not measure calories burned. Whitcomb et al. — Mazdutide high-dose U.S. Phase 1 trial (Official context · Accessed 2026-09-30)

Mazdutide is different from Tirzepatide and Retatrutide. Tirzepatide targets GLP-1/GIP; Retatrutide adds glucagon to those two. Forum talk about combining Mazdutide with Tirzepatide reflects interest in covering all three receptors, but two drugs are not interchangeable with one triple agonist. Whitcomb et al. — Mazdutide high-dose U.S. Phase 1 trial (Official context · Accessed 2026-09-30) · Mazdutide? — combination after a Retatrutide stall (Personal report · Accessed 2026-09-30)

Source context — Whitcomb et al. — Mazdutide high-dose U.S. Phase 1 trial: Deposited primary full text read through API after PMC browser challenge. Small Phase 1 study, 16 mg week-20 PK; not a community standard or personalized medicine-timing rule.

Source context — Mazdutide? — combination after a Retatrutide stall: Two drugs changed, subjective effects, no independent product verification; each drug's exact administration day unspecified. Relative display dates not converted to publication dates.

What people notice

Food noise and energy	Some report stronger hunger control and more energy, including one person changing Mazdutide and Tirzepatide together. The two drugs' contributions cannot be separated.
Scale versus body composition	One combination user reports 32 lb lost in 49 days but lower estimated muscle and no better body-fat percentage on InBody scans. The scans do not prove exact tissue loss.
Sleepiness and mood	Other reports describe nausea, sleepiness or unwanted mood/energy changes. One diary later linked initial fatigue/nausea to missed-prescription withdrawal.

Notes

Quieter food noise can make eating feel less demanding. One combination user described restored hunger control after a Retatrutide stall, alongside more energy and no nausea. Changing two drugs together makes it impossible to assign the improvement to Mazdutide alone. Mazdutide? — combination after a Retatrutide stall (Personal report · Accessed 2026-09-30)

Appetite control and body composition can diverge. A MESO contributor reported 32 lb lost in 49 days after adding Mazdutide to Tirzepatide, yet no body-fat-percentage improvement and about 10 lb less skeletal muscle on InBody scans. Those scans are estimates, not proof of exact tissue loss. MESO-Rx — GLP Non responder's, mixed-results update (Personal report · Accessed 2026-09-30)

Nausea, sleepiness and burping can accompany appetite suppression. A month-long Reddit account describes a rough first week followed by adjustment. The earlier MESO diary also reported fatigue and nausea, then corrected its explanation after discovering missed-prescription withdrawal. Neither improvement nor initial blame establishes causation. Mazdutide — first month and combination discussion (Community discussion · Accessed 2026-09-30) · MESO-Rx — Doodle's Mazdutide diary (Personal report · Accessed 2026-09-30)

Mood can feel worse even when hunger is controlled. One commenter who had tried Mazdutide, Tirzepatide and Retatrutide described similar unwanted mood/energy effects across them. The account gives no dose or timing details, and it challenges the idea of a guaranteed energy lift. Anhedonia/Depression goes away when cycling off RETA (Personal report · Accessed 2026-09-30)

Source context — MESO-Rx — GLP Non responder's, mixed-results update: Concurrent Tirzepatide; no confirmed Mazdutide amount; InBody estimates and mirror impressions, no controlled composition test.

Source context — Mazdutide — first month and combination discussion: Same freeflowofteenspirit author as the switching post. Other drug doses in replies are not Mazdutide doses; inconsistent relative date displays prevent inferred publication date.

Source context — MESO-Rx — Doodle's Mazdutide diary: One author; prior incretin exposure, moving/exertion, missed prescription and unverified product. Same-author updates and quotes are not independent reports.

Source context — Anhedonia/Depression goes away when cycling off RETA: Only this cross-agent reply supports the Mazdutide line; thread-wide Retatrutide cycle amounts and recovery times do not. Mazdutide dose/duration absent.

Doses people talk about

Single-agent diary	3 mg injected once weekly after a long break from earlier incretins. A later 9 mg target was a plan, not a completed diary dose.
Combination account	2 mg Mazdutide with 7.5 mg Tirzepatide, later 4 mg Mazdutide with 10 mg Tirzepatide. Exact injection days for each component were unstated.
Circulated weekly charts	1.5–3 mg starts and 3/6/9 mg tiers with roughly four-week steps appear in guides. The beginner/moderate/aggressive labels do not establish a suitable amount.

Notes

One diary: 3 mg by injection once weekly. Doodle reported this amount after a long break from earlier incretins, initially without a concurrent incretin. The anticipated 9 mg target was a plan, not an achieved diary dose. MESO-Rx — Doodle's Mazdutide diary (Personal report · Accessed 2026-09-30)

Combination report: 2 mg Maz + 7.5 mg Tirz, later 4 mg Maz + 10 mg Tirz. These are separate component amounts in one account comparing weekly treatment changes; each drug's injection day was unstated. A different pen user described a 2 mg Mazdutide starting amount and a final 4 mg injection. Neither report establishes a general dose range. Mazdutide? — combination after a Retatrutide stall (Personal report · Accessed 2026-09-30) · Switching from Mazdutide to Retatrutide — experiences and dosing questions (Personal report · Accessed 2026-09-30)

Circulated charts: 1.5–3 mg starts; 3, 6 and 9 mg weekly tiers. Community charts describe roughly four-week steps. Peptide Schedule repeats that ladder and the “beginner/moderate/aggressive” labels. It borrows clinical schedules; these labels are not evidence that a tier fits a particular person. Peptide Schedule — Mazdutide dosing and timing guide (Community guide · Accessed 2026-09-30)

Source context — Switching from Mazdutide to Retatrutide — experiences and dosing questions: Transition had not happened; no outcome or validated interval. Access motives preserved without procurement details.

Source context — Peptide Schedule — Mazdutide dosing and timing guide: Commercial user guide synthesizing trials and purported community discussion. Unlinked thread count/consensus claim unverified; inconsistent half-life values; trial citation mislabeled GLORY-2 while linking GLORY-1. Not firsthand or reliable kinetics evidence.

Half-life, onset & duration

Felt onset	One diary reports energy in about two hours and appetite change the next day, alongside prior incretin exposure and a busy moving day.
Felt duration	The same diary describes hunger control through the weekly interval, sometimes beyond a week. Post-stop duration is not established by these accounts.
Half-life	Clinical PK reports about eight days at 16 mg weekly, versus 7.3–44.8 days after first 2.5/3 mg doses in small cohorts. Guide estimates of 6–8 or 6–7 days are separate summaries.
Blood peak	Median about 72 hours after a first 2.5 or 3 mg dose in the small Chinese Phase 1b study; observed values ranged 12.1–170.2 hours. This is not the felt onset.

Notes

One diary: energy in about 2 hours; appetite change the next day. Doodle described an evening injection, a rapid energy lift and forgetting to eat the following afternoon. Previous incretin exposure and a busy moving day complicate interpretation. This is a reported onset, not a universal clock. MESO-Rx — Doodle's Mazdutide diary (Personal report · Accessed 2026-09-30)

One diary reports hunger control lasting through the week and sometimes longer. Doodle said suppression remained strong near the next injection and later beyond a week. This reports felt duration, not a measured half-life. The opened accounts do not establish how long appetite or energy effects last after stopping. MESO-Rx — Doodle's Mazdutide diary (Personal report · Accessed 2026-09-30)

Human PK: approximately 8 days at 16 mg weekly. A Chinese first-dose study at 2.5 or 3 mg reported a much wider 7.3–44.8-day range. These small studies used different dose conditions; neither gives a personal clearance time or measures how long appetite control feels noticeable. Whitcomb et al. — Mazdutide high-dose U.S. Phase 1 trial (Official context · Accessed 2026-09-30) · Ji et al. — Mazdutide 9 and 10 mg Chinese Phase 1b trial (Official context · Accessed 2026-09-30)

6–8 days is an affiliate guide's estimate. Peptide Reference lists 144–192 hours without identifying a matching dose-specific measurement. It is a circulated literature summary, not a value measured by users; its approval-year wording is also inconsistent with the sponsor record. Peptide Reference — Mazdutide dosage and half-life guide (Community guide · Accessed 2026-09-30)

6–7 days is another guide's estimate. Peptide Schedule uses this figure while separately repeating a wider Phase 1b range. Those study-derived claims should not be averaged or treated as personal clearance times. Felt appetite control cannot measure elimination half-life. Peptide Schedule — Mazdutide dosing and timing guide (Community guide · Accessed 2026-09-30)

Tmax (Chinese Phase 1b): Median peak exposure was about 72 hours after the first 2.5 or 3 mg dose, with an observed 12.1–170.2 hour range. [trial]

PMC9561728: introduction, procedures, PK paragraph and first-dose table context; 174.8–1075.7 hours, median Tmax ~72 hours; heart-rate discussion. Ji et al. — Mazdutide 9 and 10 mg Chinese Phase 1b trial (Official context · Accessed 2026-09-30)

Source context — Ji et al. — Mazdutide 9 and 10 mg Chinese Phase 1b trial: Eight active participants per cohort; first-dose PK at 2.5/3 mg. PMC opened full body first but later challenge; deposited XML recovered. Mouse/in-vitro introduction context remains preclinical, not human calorie-burn proof.

Source context — Peptide Reference — Mazdutide dosage and half-life guide: Commercial affiliation visible; generic figure not tied to dose/population. 2024 approval claim conflicts with sponsor documentation; effect and safety claims not adopted.

Cycles people discuss

Ongoing weekly use	Discussion includes dose holds, maintenance, supply interruptions and lower-step restarts. No consistent on/off course or validated self-directed restart rule emerges.
Switching gap	A 7–10-day gap before Retatrutide was one user's question, not a completed transition or established washout interval.

Notes

Weekly ongoing use and dose holds appear in discussion. Community notes describe holding a step for tolerability, maintaining at goal weight versus stopping, supply interruptions and lower-step restarts. They give no consistent on/off course or validated restart rule.

A 7–10-day switching gap was a question, not an outcome. The September pen user asked about moving to Retatrutide after this interval. Replies described a different Tirzepatide-to-Retatrutide switch. They do not answer Mazdutide washout, rebound timing or safe transition dosing; circulating missed-dose habits are also class extrapolation. Switching from Mazdutide to Retatrutide — experiences and dosing questions (Personal report · Accessed 2026-09-30)

Stacks

Tirzepatide combinations	Actual reports combine Tirzepatide and Mazdutide, sometimes nicknamed Ghetto Reta. They do not establish synergy, equivalence to Retatrutide or combination safety.
Training and meal support	Protein and resistance training recur in lean-mass discussions. Electrolytes, fiber, smaller meals, ginger and prescribed nausea medicines appear as coping measures.
Other peptide co-use	CJC/Ipamorelin, Tesamorelin or MK-677 and BPC-157/TB-500/GHK-Cu appear for separate goals; co-use does not show added fat loss or muscle protection.

Notes

“Ghetto Reta” describes an experimental combination. Reddit posters use this nickname for Tirzepatide plus Mazdutide or Survodutide. One 2024 user called their Mazdutide combination successful but never supplied amounts or measured outcomes. Reports exist, yet they cannot establish synergy or combination safety. Mazdutide? — combination after a Retatrutide stall (Personal report · Accessed 2026-09-30) · Stack — Mazdutide or Survodutide with Tirz? (Personal report · Accessed 2026-09-30) · Mazdutide — first month and combination discussion (Community discussion · Accessed 2026-09-30)

Scale loss is only part of what people care about. Community discussion emphasizes protein and resistance training because appetite loss can undermine meals and recovery. Electrolytes, fiber, smaller meals, ginger and prescribed nausea medicines also appear as coping talk, not evidence that a difficult dose becomes safe.

Additional peptides make attribution harder. Co-use reports mention CJC/Ipamorelin, Tesamorelin or MK-677 for muscle/sleep, and BPC-157, TB-500 or GHK-Cu for other goals. Their co-occurrence does not show that they improve Mazdutide fat loss or protect lean mass.

Source context — Stack — Mazdutide or Survodutide with Tirz?: No quantitative outcome or component amount supplied. Weekly/split reply is opinion, not measured kinetics.

Watch for

GI symptoms and pulse	Nausea, burping, sleepiness and clinical pulse increases appear. Persistent abdominal pain, dehydration and severe gastric-motility problems deserve attention.
Other medicines	Insulin/sulfonylureas raise low-glucose concerns. Delayed oral absorption is discussed, but these records establish no spacing rule for other medicines.
Pregnancy and thyroid history	The record flags pregnancy/breastfeeding, medullary thyroid cancer history and MEN2 as class cautions; excluded trial groups do not have established safety here.
Research-vial uncertainty	China's recorded approvals do not verify a research vial's identity, strength or sterility, or make it equivalent to controlled trial material.

Notes

Severe GI symptoms and heart-rate changes deserve attention. The clinical literature reports GI events and pulse increases. Class cautions include persistent abdominal or right-upper-abdominal pain, dehydration, gallbladder problems and severe gastric-motility disease. Absence of symptoms in a testimonial does not settle these risks. Ji et al. — Chinese Mazdutide Phase 2 obesity trial (Official context · Accessed 2026-09-30) · Ji et al. — Mazdutide 9 and 10 mg Chinese Phase 1b trial (Official context · Accessed 2026-09-30)

Insulin, sulfonylureas and oral medicines complicate the picture. Class discussion flags low-glucose risk with glucose-lowering drugs and concerns about delayed oral absorption. A small high-dose study found only mild gastric-emptying changes; it cannot establish a spacing rule for levothyroxine, warfarin or other medicines. Whitcomb et al. — Mazdutide high-dose U.S. Phase 1 trial (Official context · Accessed 2026-09-30)

Pregnancy and thyroid-history cautions remain relevant. Class discussion flags pregnancy/breastfeeding, personal or family medullary thyroid cancer and MEN2. The Phase 2 study excluded relevant thyroid histories. Rodent class concerns and screened trial populations do not establish either human thyroid harm or safety in excluded groups. Ji et al. — Chinese Mazdutide Phase 2 obesity trial (Official context · Accessed 2026-09-30)

Trials support weight loss, with GI symptoms during escalation. The Chinese Phase 2 trial found greater weight reduction than placebo. Its controlled clinical material and group averages cannot predict the results of a community vial. Ji et al. — Chinese Mazdutide Phase 2 obesity trial (Official context · Accessed 2026-09-30)

China approvals do not validate research vials. Innovent records China's weight-management and diabetes approvals in 2025. FDA's August 2026 letter identifies a seller's Mazdutide as an unapproved new drug. A matching name does not establish equal identity, strength or sterility. Innovent 2025 annual results — regulatory actions (Official context · Accessed 2026-09-30) · FDA warning letter — NuScience Peptides LLC (Official context · Accessed 2026-09-30)

Source context — Ji et al. — Chinese Mazdutide Phase 2 obesity trial: Chinese trial population, controlled material, 24-week interim analysis. No trial-vial equivalence, broad safety assurance, or self-directed restart/missed-dose rules.

Source context — Innovent 2025 annual results — regulatory actions: Sponsor disclosure, not full prescribing information; 9 mg application acceptance is not approval and later status was not established from this March document.

Source context — FDA warning letter — NuScience Peptides LLC: Seller-specific enforcement finding, not a new compound-eligibility policy or complete regulatory label.

Full notes

What Mazdutide is

One peptide activates two receptors. Also called IBI362 or LY3305677, it mimics oxyntomodulin, a gut hormone. The GLP-1 side helps regulate hunger and glucose; the glucagon side is studied for additional metabolic effects. Feeling energized does not measure calories burned. Official context
Mazdutide is different from Tirzepatide and Retatrutide. Tirzepatide targets GLP-1/GIP; Retatrutide adds glucagon to those two. Forum talk about combining Mazdutide with Tirzepatide reflects interest in covering all three receptors, but two drugs are not interchangeable with one triple agonist. Official context Personal report

What people hope to get from it

Quieter food noise can make eating feel less demanding. One combination user described restored hunger control after a Retatrutide stall, alongside more energy and no nausea. Changing two drugs together makes it impossible to assign the improvement to Mazdutide alone. Personal report
Appetite control and body composition can diverge. A MESO contributor reported 32 lb lost in 49 days after adding Mazdutide to Tirzepatide, yet no body-fat-percentage improvement and about 10 lb less skeletal muscle on InBody scans. Those scans are estimates, not proof of exact tissue loss. Personal report

Doses people discuss

One diary: 3 mg by injection once weekly. Doodle reported this amount after a long break from earlier incretins, initially without a concurrent incretin. The anticipated 9 mg target was a plan, not an achieved diary dose. Personal report
Combination report: 2 mg Maz + 7.5 mg Tirz, later 4 mg Maz + 10 mg Tirz. These are separate component amounts in one account comparing weekly treatment changes; each drug's injection day was unstated. A different pen user described a 2 mg Mazdutide starting amount and a final 4 mg injection. Neither report establishes a general dose range. Personal report Personal report
Circulated charts: 1.5–3 mg starts; 3, 6 and 9 mg weekly tiers. Community charts describe roughly four-week steps. Peptide Schedule repeats that ladder and the “beginner/moderate/aggressive” labels. It borrows clinical schedules; these labels are not evidence that a tier fits a particular person. Community Community guide

Half-life discussed online

6–8 days is an affiliate guide's estimate. Peptide Reference lists 144–192 hours without identifying a matching dose-specific measurement. It is a circulated literature summary, not a value measured by users; its approval-year wording is also inconsistent with the sponsor record. Community guide
6–7 days is another guide's estimate. Peptide Schedule uses this figure while separately repeating a wider Phase 1b range. Those study-derived claims should not be averaged or treated as personal clearance times. Felt appetite control cannot measure elimination half-life. Community guide

When people first notice it

One diary: energy in about 2 hours; appetite change the next day. Doodle described an evening injection, a rapid energy lift and forgetting to eat the following afternoon. Previous incretin exposure and a busy moving day complicate interpretation. This is a reported onset, not a universal clock. Personal report

How long an effect feels noticeable

One diary reports hunger control lasting through the week and sometimes longer. Doodle said suppression remained strong near the next injection and later beyond a week. This reports felt duration, not a measured half-life. The opened accounts do not establish how long appetite or energy effects last after stopping. Personal report

Courses, pauses and switching

Weekly ongoing use and dose holds appear in discussion. Community notes describe holding a step for tolerability, maintaining at goal weight versus stopping, supply interruptions and lower-step restarts. They give no consistent on/off course or validated restart rule. Community
A 7–10-day switching gap was a question, not an outcome. The September pen user asked about moving to Retatrutide after this interval. Replies described a different Tirzepatide-to-Retatrutide switch. They do not answer Mazdutide washout, rebound timing or safe transition dosing; circulating missed-dose habits are also class extrapolation. Personal report Community

What the studies add

Human PK: approximately 8 days at 16 mg weekly. A Chinese first-dose study at 2.5 or 3 mg reported a much wider 7.3–44.8-day range. These small studies used different dose conditions; neither gives a personal clearance time or measures how long appetite control feels noticeable. Official context Official context
Trials support weight loss, with GI symptoms during escalation. The Chinese Phase 2 trial found greater weight reduction than placebo. Its controlled clinical material and group averages cannot predict the results of a community vial. Official context
China approvals do not validate research vials. Innovent records China's weight-management and diabetes approvals in 2025. FDA's August 2026 letter identifies a seller's Mazdutide as an unapproved new drug. A matching name does not establish equal identity, strength or sterility. Official context Official context

What to watch for

Nausea, sleepiness and burping can accompany appetite suppression. A month-long Reddit account describes a rough first week followed by adjustment. The earlier MESO diary also reported fatigue and nausea, then corrected its explanation after discovering missed-prescription withdrawal. Neither improvement nor initial blame establishes causation. Reddit r/Biohacking Personal report
Mood can feel worse even when hunger is controlled. One commenter who had tried Mazdutide, Tirzepatide and Retatrutide described similar unwanted mood/energy effects across them. The account gives no dose or timing details, and it challenges the idea of a guaranteed energy lift. Personal report
Severe GI symptoms and heart-rate changes deserve attention. The clinical literature reports GI events and pulse increases. Class cautions include persistent abdominal or right-upper-abdominal pain, dehydration, gallbladder problems and severe gastric-motility disease. Absence of symptoms in a testimonial does not settle these risks. Official context Official context Community
Insulin, sulfonylureas and oral medicines complicate the picture. Class discussion flags low-glucose risk with glucose-lowering drugs and concerns about delayed oral absorption. A small high-dose study found only mild gastric-emptying changes; it cannot establish a spacing rule for levothyroxine, warfarin or other medicines. Community Official context
Pregnancy and thyroid-history cautions remain relevant. Class discussion flags pregnancy/breastfeeding, personal or family medullary thyroid cancer and MEN2. The Phase 2 study excluded relevant thyroid histories. Rodent class concerns and screened trial populations do not establish either human thyroid harm or safety in excluded groups. Community Official context

From community discussion

“Ghetto Reta” describes an experimental combination. Reddit posters use this nickname for Tirzepatide plus Mazdutide or Survodutide. One 2024 user called their Mazdutide combination successful but never supplied amounts or measured outcomes. Reports exist, yet they cannot establish synergy or combination safety. Personal report Personal report Reddit r/Biohacking
Scale loss is only part of what people care about. Community discussion emphasizes protein and resistance training because appetite loss can undermine meals and recovery. Electrolytes, fiber, smaller meals, ginger and prescribed nausea medicines also appear as coping talk, not evidence that a difficult dose becomes safe. Community
Additional peptides make attribution harder. Co-use reports mention CJC/Ipamorelin, Tesamorelin or MK-677 for muscle/sleep, and BPC-157, TB-500 or GHK-Cu for other goals. Their co-occurrence does not show that they improve Mazdutide fat loss or protect lean mass. Community
Switching can reflect access rather than a failed drug. The pen user's move from China to Switzerland prompted their transition question. Their earlier month report described adjustment after nausea and sleepiness. These are the same author, not two independent responders; the transition's outcome remains unknown. Personal report Reddit r/Biohacking