Peptide

Maridebart cafraglutide

Also known as

MariTide · AMG 133 · AMG-133 · AMG133 · maridebart cafraglutide · MariTide (Amgen) · GIPR antagonist / GLP-1 agonist conjugate · GIPR-Ab + dual GLP-1 peptide conjugate · peptide–antibody conjugate obesity candidate · monthly MariTide (pipeline shorthand)

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

What it is

Identity	MariTide, or AMG 133, is an investigational antibody–peptide injection for weight loss. Its antibody blocks GIP receptors while two attached peptides activate GLP-1 receptors.
Clinical form	A long-acting biologic injected beneath the skin. A gray-market vial bearing its name does not establish equivalence to the manufactured trial product.

Notes

Two activities in one large molecule. An antibody blocks GIP receptors and carries two peptides activating GLP-1 receptors. Forum readers contrast this with tirzepatide's GIP activation; opposite directions do not establish which works better. Véniant et al.: GIPR antagonist conjugated to GLP-1 analogues, preclinical and Phase 1 settings (Official context · Accessed 2026-09-30) · Next gen weight loss drug MariTide is a once a month (or maybe twice a year) injection (Community discussion · Accessed 2026-09-30)

Maridebart cafraglutide, also called MariTide or AMG 133, is an investigational antibody–peptide injection discussed for weight loss with fewer shots. Claimed trial participants describe quieter cravings and weight loss, but also vomiting, fatigue, constipation or little noticeable effect. Blinded assignments make these personal accounts uncertain.

A long-acting subcutaneous biologic. The clinical form goes under the skin. Preserved biohacking discussion distinguishes this conjugate from ordinary peptide powders; a vial bearing its name does not establish the trial product's identity or strength.

Source context — Véniant et al.: GIPR antagonist conjugated to GLP-1 analogues, preclinical and Phase 1 settings: Small Phase 1 cohorts, mostly sponsor authors. Weight was exploratory; no long-term off-drug guarantee. Clean Nature URL initially failed; query URL returned readable full body. Only the inspected HTML body, not all downloadable supplements/source files, is claimed reviewed.

Source context — Next gen weight loss drug MariTide is a once a month (or maybe twice a year) injection: OP repeats media/sponsor claims; anticipated duration/half-life is not measured kinetics. Most replies discuss other GLP-1 drugs or hopes, not MariTide use. Possible same account as Angelica_Picklez is not counted twice.

What people notice

Quieter cravings	One claimed participant described cravings quieting while some food noise remained. Others reported substantial weight loss, but their doses and active-treatment assignments were unverified.
Uneven experiences	One person felt appetite loss immediately; another noticed less food noise after the second injection and less interest in food by the third. Others reported little change or no side effects under blinding.

Notes

Less food noise and fewer cravings. A Mounjaro commenter initially described food noise as gone, then clarified that a background hum remained while cravings had quieted. They reported ongoing weight loss without the nausea they had experienced on Ozempic; their MariTide assignment was uncertain. Next gen weight loss drug MariTide is a once a month (or maybe twice a year) injection (Community discussion · Accessed 2026-09-30)

Weight change with different tolerability. nbnojo reported more than 60 lb lost over a little more than a year, with persistent constipation and monthly clinic injections. A German participant separately reported 142 kg to 109 kg over 52 weeks and only slight nausea with the first two doses, alongside walking and gym activity. Monthly injectable GLP-1 MariTide (Personal report · Accessed 2026-09-30) · Starting the MariTide clinical next week (Personal report · Accessed 2026-09-30)

nbnojo comments: July 5 experience and later dose-blinding clarification; web body lines 114–159; monthly clinic appointments, >60 lb, persistent constipation, Phase 2/3 uncertainty, extension assignment. Monthly injectable GLP-1 MariTide (Personal report · Accessed 2026-09-30)

First injection to third injection, or no clear change. Angelica_Picklez felt nothing initially while her husband noticed appetite loss immediately; her food noise declined after the second shot and interest in food fell by the third. Sldsmb11 reported no weight loss or side effects before the full-dose injection. Blinding prevents calling that confirmed drug nonresponse. Maritide clinical trial participation (Personal report · Accessed 2026-09-30)

Symptoms cannot reveal a blinded assignment. Witty_Recognition_64 reported no side effects at their assigned highest dose. nbnojo later questioned the trial phase. Neither account identifies assigned mg or proves allocation. Maritide trial phase 3 (Personal report · Accessed 2026-09-30) · Monthly injectable GLP-1 MariTide (Personal report · Accessed 2026-09-30)

Source context — Monthly injectable GLP-1 MariTide: Anonymous claimed trial participation not independently verified. Same person appears in other threads; not counted as independent users. Neither assigned dose nor active/placebo allocation known. Speculative 340 mg remembered by a different screening commenter is not verified dosing. Exact OP publication date not verified.

Source context — Starting the MariTide clinical next week: Self-reported trial and body-composition/blood claims unverified; no assigned mg or allocation. Only scale/lifestyle/nausea details carried visibly; no objective body-fat or inflammatory-biomarker conclusion.

Source context — Maritide clinical trial participation: Anonymous blinded trial claims; usernames overlap other opened threads. Relative dates only in this body, so no invented publication date. Feeling unchanged does not establish active-drug nonresponse.

Source context — Maritide trial phase 3: Highest assigned dose is not a disclosed mg value or confirmed highest study arm. Blinded placebo possibilities and enrollment unverifiable.

Doses people talk about

Participant milligrams unknown	Monthly clinic visits and loading injections are described, but actual assigned amounts are often undisclosed. These diaries supply no usable community dose range.
Separate Phase 2 arms	Study quantities include 140, 280 or 420 mg subcutaneously every four weeks, and a separate 420 mg every-eight-week arm. These describe the proprietary conjugate, without a consumer regimen.
Different study transitions	Phase 2 also escalated 70 mg to 420 mg over four or twelve weeks. A separate low-start study used 21, 35 or 70 mg on day one, 70 mg on day fifteen, then 350 mg on day twenty-nine.

Notes

Monthly clinic injection; actual mg often unknown. nbnojo says neither they nor their team know their dose. Others describe loading injections followed by monthly injections without milligrams. These trial experiences supply no usable community amount range; published mg schedules appear separately below. Monthly injectable GLP-1 MariTide (Personal report · Accessed 2026-09-30) · Maritide clinical trial participation (Personal report · Accessed 2026-09-30)

Clinical mg schedules describe the proprietary conjugate. Amgen's Phase 2 report lists 140, 280 or 420 mg SC every four weeks; a separate 420 mg every-eight-week arm; and 70 mg starts escalating to 420 mg over four or twelve weeks. Part 2 studied monthly 70, 140 or 420 mg, or 420 mg every twelve weeks. These are trial quantities, not consumer instructions. Amgen: Phase 2 obesity results at ADA Scientific Sessions (Official context · Accessed 2026-09-30)

Lower starts were studied for tolerability. Sponsor PK-LDI schedules used SC 21, 35 or 70 mg on day one, 70 mg on day fifteen, then 350 mg on day twenty-nine. The Phase 3 program adopted 21, 35 and 70 mg steps over eight weeks before assigned maintenance. These are distinct study designs. Amgen: Phase 2 obesity results at ADA Scientific Sessions (Official context · Accessed 2026-09-30)

Source context — Amgen: Phase 2 obesity results at ADA Scientific Sessions: Sponsor communication rather than independent full Phase 2 paper. NEJM DOI and PubMed body access failed; no full-paper adverse-event table claimed reviewed. Sponsor results must retain analysis and continued-treatment qualifiers.

Half-life, onset & duration

Felt onset	Immediate appetite change, change after the second or third injection, and little noticeable change all appear in blinded accounts. No predictable first-dose window is established.
Felt duration	One person noticed hunger returning before the next monthly visit. Another described nausea and fatigue for 2–3 days after doses, improving later; a different person vomited for four days.
Half-life	Human Phase 1 assays reported 14–16 days for intact AMG 133 versus 21–24 days for total antibody signal, including antibody without attached peptides. These are separate measurements.
Blood peak	Days 4–7 after subcutaneous administration in Phase 1. Blood concentration peak does not establish when appetite changes begin.

Notes

Symptoms can last days and change over time. Baltharus described nausea and fatigue for 2–3 days after monthly doses around month four, then little noticeable nausea or fatigue in a later update. Another participant described vomiting after meals for four days after the second shot and considered withdrawing. Neither defines a universal symptom window. Mari-Tide 2 (Personal report · Accessed 2026-09-30)

Hunger can return before the next monthly shot. Gummyb3ar13 noticed more hunger during the weeks before the week-eight injection and felt the smaller dose had not lasted the month. That is one blinded impression, not proof of a fixed four-week appetite effect. Maritide clinical trial participation (Personal report · Accessed 2026-09-30)

Human Phase 1: separate half-life assays. Véniant reports 14–16 days intact, versus 21–24 days total, including antibody without attached peptides. Peak exposure: days 4–7, not felt onset. High-dose weight reduction persisted 150 days after the final injection; this does not establish permanent maintenance. Véniant et al.: GIPR antagonist conjugated to GLP-1 analogues, preclinical and Phase 1 settings (Official context · Accessed 2026-09-30)

Source context — Mari-Tide 2: Unverified enrollment/allocation/dose; symptoms and diet effects self-reported. Baltharus, OP and others recur in the participation thread; not independent confirmations. Relative comment dates retained as relative, not converted.

Cycles people discuss

Long trial courses	Participants describe months of visits and hoped-for extensions, sometimes beyond a year. One proposed rollover was 48 weeks of dosing plus 12 weeks of safety follow-up; it was not a completed community cycle.
After stopping	Fear of regain appears, without a documented outcome in that account. Maintenance results with continued lower or less frequent doses do not establish permanent off-drug loss.

Notes

Long trial courses, not established on/off cycles. Participants discuss months of scheduled clinic visits and possible extensions; nbnojo wanted to continue beyond a year. Baltharus described a proposed 60-week rollover: 48 weeks of dosing plus 12 weeks of safety follow-up, with eligibility uncertain. Neither is a validated biohacker cycling pattern. Monthly injectable GLP-1 MariTide (Personal report · Accessed 2026-09-30) · Mari-Tide 2 (Personal report · Accessed 2026-09-30)

Fear of regain is not observed regain. A blinded participant worried about losing access after the study despite improved habits and a reported fall from roughly 230 lb to 190 lb. The post anticipates regain; it does not document what happened after stopping. Understanding I'm probably going to gain all the weight back (Personal report · Accessed 2026-09-30)

Headlines and maintenance need their qualifiers. Amgen's roughly 20% one-year headline assumes continued treatment; the treatment-policy obesity-arm results were 12.3–16.2%. In February 2026 the sponsor said a large majority of selected responders maintained loss for another year on lower monthly or quarterly dosing. Continued maintenance treatment does not demonstrate permanent off-drug loss. Amgen: Phase 2 obesity results at ADA Scientific Sessions (Official context · Accessed 2026-09-30) · Amgen fourth-quarter/full-year 2025 results: Phase 2 Part 2 (Official context · Accessed 2026-09-30)

Source context — Understanding I'm probably going to gain all the weight back: Post says both one year and week 36; timing internally inconsistent, so not used to establish exact duration. Future regain is anticipated, not observed. Replies about compounded products are not endorsed or reproduced as sourcing advice.

Source context — Amgen fourth-quarter/full-year 2025 results: Phase 2 Part 2: Exploratory selected-responder sponsor summary; full arm-level Part 2 paper and withdrawal results not inspected. Continued lower/quarterly dosing is not drug-free maintenance.

Stacks

Comparisons, without a stack	The saved discussion compares semaglutide, tirzepatide, retatrutide and cagrilintide. It documents no validated MariTide combination or DIY switch schedule.
Lifestyle alongside trials	Diet and physical activity support accompany trial treatment. One participant also described walking and gym activity during weight loss.

Notes

Investigational status and combination uncertainty. Phase 3 development is ongoing. Preserved discussions compare semaglutide, tirzepatide, retatrutide and cagrilintide, rather than documenting validated MariTide stacks. Gray-market identity, sterility and antibody-related immune uncertainty remain distinct from clinical-trial evidence. Amgen second-quarter 2026 pipeline update (Official context · Accessed 2026-09-30)

Switching and surgery questions remain questions. Users ask about maintenance switches and elective procedures. Preserved discussions raise delayed-stomach-emptying and dehydration concerns by GLP-1 analogy, not as MariTide-specific labeling. These accounts establish no DIY cross-taper or stack. Next gen weight loss drug MariTide is a once a month (or maybe twice a year) injection (Community discussion · Accessed 2026-09-30)

Trial co-interventions: Diet, physical activity counseling, and standard obesity-trial lifestyle support co-run with drug — not stimulant stacks. [trial]

Source context — Amgen second-quarter 2026 pipeline update: Sponsor development status as accessed; trial designs are not approved schedules or completed outcomes.

Watch for

Poor intake and gut symptoms	Vomiting, nausea, fatigue, constipation, sulfur burps and difficulty eating enough protein are reported. Trouble keeping fluids down is a medical issue, even when weight is falling.
Limited control over a long dose	Some welcome fewer injections; others worry about prolonged poor tolerability. Blinded symptoms cannot identify the drug or assigned dose.
Product and long-term unknowns	The candidate remains investigational in the saved records. Gray-market identity, sterility and immune risks are separate from evidence about the clinical biologic.

Notes

Poor intake can accompany impressive scale changes. Participant reports include vomiting, sulfur burps, fatigue and difficulty eating enough protein. One person reported hair loss and attributed their doctor's explanation to insufficient protein. Rapid loss during vomiting is not a reassuring benefit; difficulty keeping fluids down is a medical issue. Mari-Tide 2 (Personal report · Accessed 2026-09-30)

Fewer injections appeal, but opinions differ. Some weekly-shot users welcome longer intervals. Others fear less control over poor tolerability, or already find weekly shots easy. Next gen weight loss drug MariTide is a once a month (or maybe twice a year) injection (Community discussion · Accessed 2026-09-30)

Source context — Maritide trial phase 3: Highest assigned dose is not a disclosed mg value or confirmed highest study arm. Blinded placebo possibilities and enrollment unverifiable.

Source context — Amgen second-quarter 2026 pipeline update: Sponsor development status as accessed; trial designs are not approved schedules or completed outcomes.

Full notes

What MariTide is

Two activities in one large molecule. An antibody blocks GIP receptors and carries two peptides activating GLP-1 receptors. Forum readers contrast this with tirzepatide's GIP activation; opposite directions do not establish which works better. Official context Reddit r/Mounjaro
A long-acting subcutaneous biologic. The clinical form goes under the skin. Preserved biohacking discussion distinguishes this conjugate from ordinary peptide powders; a vial bearing its name does not establish the trial product's identity or strength. Community

What people hope for and report

Less food noise and fewer cravings. A Mounjaro commenter initially described food noise as gone, then clarified that a background hum remained while cravings had quieted. They reported ongoing weight loss without the nausea they had experienced on Ozempic; their MariTide assignment was uncertain. Reddit r/Mounjaro
Weight change with different tolerability. nbnojo reported more than 60 lb lost over a little more than a year, with persistent constipation and monthly clinic injections. A German participant separately reported 142 kg to 109 kg over 52 weeks and only slight nausea with the first two doses, alongside walking and gym activity. Personal report Personal report
Fewer injections appeal, but opinions differ. Some weekly-shot users welcome longer intervals. Others fear less control over poor tolerability, or already find weekly shots easy. Reddit r/Mounjaro

Doses people discuss

Monthly clinic injection; actual mg often unknown. nbnojo says neither they nor their team know their dose. Others describe loading injections followed by monthly injections without milligrams. These trial experiences supply no usable community amount range; published mg schedules appear separately below. Personal report Personal report

Half-life claims in discussion

Three to six months is speculation, not measured half-life. A Mounjaro commenter raises this hypothetical while worrying about prolonged sickness. Hoped-for injection spacing or persistent weight change is not blood clearance. No participant measures half-life; separate human assays appear below. Reddit r/Mounjaro

When people notice effects

First injection to third injection, or no clear change. Angelica_Picklez felt nothing initially while her husband noticed appetite loss immediately; her food noise declined after the second shot and interest in food fell by the third. Sldsmb11 reported no weight loss or side effects before the full-dose injection. Blinding prevents calling that confirmed drug nonresponse. Personal report

How long effects feel noticeable

Symptoms can last days and change over time. Baltharus described nausea and fatigue for 2–3 days after monthly doses around month four, then little noticeable nausea or fatigue in a later update. Another participant described vomiting after meals for four days after the second shot and considered withdrawing. Neither defines a universal symptom window. Personal report
Hunger can return before the next monthly shot. Gummyb3ar13 noticed more hunger during the weeks before the week-eight injection and felt the smaller dose had not lasted the month. That is one blinded impression, not proof of a fixed four-week appetite effect. Personal report

Courses, extensions and stopping

Long trial courses, not established on/off cycles. Participants discuss months of scheduled clinic visits and possible extensions; nbnojo wanted to continue beyond a year. Baltharus described a proposed 60-week rollover: 48 weeks of dosing plus 12 weeks of safety follow-up, with eligibility uncertain. Neither is a validated biohacker cycling pattern. Personal report Personal report
Fear of regain is not observed regain. A blinded participant worried about losing access after the study despite improved habits and a reported fall from roughly 230 lb to 190 lb. The post anticipates regain; it does not document what happened after stopping. Personal report

Tolerability and trial uncertainty

Poor intake can accompany impressive scale changes. Participant reports include vomiting, sulfur burps, fatigue and difficulty eating enough protein. One person reported hair loss and attributed their doctor's explanation to insufficient protein. Rapid loss during vomiting is not a reassuring benefit; difficulty keeping fluids down is a medical issue. Personal report
Symptoms cannot reveal a blinded assignment. Witty_Recognition_64 reported no side effects at their assigned highest dose. nbnojo later questioned the trial phase. Neither account identifies assigned mg or proves allocation. Personal report Personal report
Investigational status and combination uncertainty. Phase 3 development is ongoing. Preserved discussions compare semaglutide, tirzepatide, retatrutide and cagrilintide, rather than documenting validated MariTide stacks. Gray-market identity, sterility and antibody-related immune uncertainty remain distinct from clinical-trial evidence. Official context Community

Separately identified trial and animal context

Human Phase 1: separate half-life assays. Véniant reports 14–16 days intact, versus 21–24 days total, including antibody without attached peptides. Peak exposure: days 4–7, not felt onset. High-dose weight reduction persisted 150 days after the final injection; this does not establish permanent maintenance. Official context
Animal half-lives stay separate. Mouse IV 5 mg/kg: 118 hours intact, 206 total. Obese-monkey SC 0.5–1 mg/kg: 189–222 hours intact, 231–284 total. Separate female-monkey SC 3 mg/kg: 207 and 292 hours. These are not human estimates. Animal context
Clinical mg schedules describe the proprietary conjugate. Amgen's Phase 2 report lists 140, 280 or 420 mg SC every four weeks; a separate 420 mg every-eight-week arm; and 70 mg starts escalating to 420 mg over four or twelve weeks. Part 2 studied monthly 70, 140 or 420 mg, or 420 mg every twelve weeks. These are trial quantities, not consumer instructions. Official context
Lower starts were studied for tolerability. Sponsor PK-LDI schedules used SC 21, 35 or 70 mg on day one, 70 mg on day fifteen, then 350 mg on day twenty-nine. The Phase 3 program adopted 21, 35 and 70 mg steps over eight weeks before assigned maintenance. These are distinct study designs. Official context
Headlines and maintenance need their qualifiers. Amgen's roughly 20% one-year headline assumes continued treatment; the treatment-policy obesity-arm results were 12.3–16.2%. In February 2026 the sponsor said a large majority of selected responders maintained loss for another year on lower monthly or quarterly dosing. Continued maintenance treatment does not demonstrate permanent off-drug loss. Official context Official context

From community experience and discussion

Eating habits change alongside appetite. Baltharus reported greasy food worsened gut symptoms and diet changes helped. Another participant found only fruit and vegetables appealing, making protein intake difficult. Appetite suppression could feel useful and burdensome together. Personal report
Progress may slow without stopping. Gummyb3ar13 reported 50 lb lost by week 28, but the last 10 lb took almost three months; they later reported 60 lb total. This individual slowdown challenges the idea that a trial's average lack of plateau means every person loses at a constant pace. Personal report
Switching and surgery questions remain questions. Users ask about maintenance switches and elective procedures. Preserved discussions raise delayed-stomach-emptying and dehydration concerns by GLP-1 analogy, not as MariTide-specific labeling. These accounts establish no DIY cross-taper or stack. Reddit r/Mounjaro Community