What it does
Tirzepatide is a synthetic peptide that activates both the GIP and GLP-1 receptors, slowing gastric emptying, suppressing appetite, and improving insulin sensitivity. It is FDA-approved as Mounjaro for Type 2 diabetes (2022) and as Zepbound for chronic weight management (2023). The SURPASS and SURMOUNT trial programs together enrolled more than 7,000 participants and consistently demonstrated superiority over placebo and over comparator GLP-1 agonists at the clinically relevant endpoints.
Used for
Dose
- Starting
- 2,500 mcg · once weekly
- Common
- 8,750 mcg · once weekly
- Upper
- 15,000 mcg · once weekly
- When
- MorningOnce-weekly. Time-of-day functionally flexible — pick a consistent day + time the user can reliably hit. Wednesday morning a common community choice to spread GI side-effects across the workweek.
- How long
- Continuous (no on/off cycling) on / — off
- Site
- subcutaneous
- Food
- any
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⚠ Caution
- Personal or family history of medullary thyroid carcinoma (boxed warning, extrapolated from GLP-1 class data in rodent models)
- Multiple Endocrine Neoplasia syndrome type 2 (boxed warning)
- Known hypersensitivity to tirzepatide or excipients
- Pregnancy: avoid; discontinue 2 months before planned conception
- Severe gastroparesis or gastrointestinal motility disorders
Medications & conditions
- Dual GLP-1 receptor agonist therapy — additive riskStacking tirzepatide with another GLP-1 receptor agonist creates redundant mechanism overlap. The combination has not been studied in clinical trials and carries amplified risk of GI side effects (nausea, diarrhea), pancreatitis, and hypoglycemia (especially with concurrent insulin or sulfonylureas). One agent at a time is the documented standard of care.
- Tirzepatide with insulin or sulfonylurea — hypoglycemia riskAdding tirzepatide to insulin or sulfonylurea therapy materially increases hypoglycemia risk. Existing clinical guidance recommends reducing the dose of the concurrent agent when starting GLP-1/GIP therapy. Coordinate with the prescribing clinician — do not start without supervision.
Will it work for me?
Establish a baseline (2–3 readings over 1–2 weeks before starting), then track at consistent intervals.
- Tier 1 — Human RCTHbA1c↓· repeat at 3 months
- Tier 1 — Human RCTFasting insulin (HOMA-IR input)↓· 12 weeksHOMA-IR (fasting glucose × fasting insulin ÷ 405) improves more than with semaglutide, attributed to GIP-driven insulin sensitivity.
- Tier 1 — Human RCTFasting glucose (HOMA-IR input)↓· 8–12 weeks
- Tier 1 — Human RCTAdiponectin↑· pre + 12 weeks post (LabCorp/Quest send-out)GIP-specific marker — rises more with tirzepatide than semaglutide. No registry slug; order as a send-out.
- Tier 1 — Human RCTLiver enzymes (ALT/AST)↓· 12 weeksRelevant in a fatty-liver context with elevated baseline enzymes.
- Tier 2 — Human observationalFIB-4 score↓· 12+ weeksCalculated proxy (age + AST + ALT + platelets) for liver fibrosis; no registry slug — free online calculators (MDCalc).
- Tier 1 — Human RCTTriglycerides (lipid panel)↓· 12 weeks
- Tier 2 — Human observationalLean mass % via DEXA↓· baseline + at rapid-weight-loss checkpointsSome lean-mass loss is expected in proportion to total loss — this is monitoring, not an efficacy goal. No registry slug.
- Tier 3 — Animal / in vitroBody weight↓· tracked weekly; ~1.5–2.5 lb/week early; SURMOUNT-1 magnitude ~22.5% at 72 weeksFaster trajectory than semaglutide.
- Tier 3 — Animal / in vitroBlood pressure↓· 8–12 weeksTypical reduction ~5–7 mmHg.
Your stack
Track this peptide in your protocol — dose, schedule, vials on hand, refill projection. Stays in your browser; no account needed.
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