What is Tirzepatide?
Tirzepatide is a novel 39-amino-acid synthetic peptide that activates both GIP and GLP-1 receptors. The dual-agonist approach has produced the largest weight reductions seen in clinical pharmacotherapy to date, with average losses around 20–22% at high doses in SURMOUNT-1.
Mechanism of action
Simultaneous activation of GIP and GLP-1 receptors enhances insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite via central pathways. GIP agonism may additionally support adipose tissue lipid handling.
Researched benefits
- Average weight reduction of ~20% at 15 mg weekly (SURMOUNT-1)
- Superior HbA1c reductions vs. semaglutide in head-to-head data
- Improvements in MASH/NAFLD biomarkers
- Sleep apnea improvements in dedicated trials
Researched dosage
Most research protocols use 2500–15000 mcg administered 1× per day via subcutaneous injection. Clinical escalation: 2.5 mg weekly for 4 weeks, then 5, 7.5, 10, 12.5, 15 mg at 4-week intervals as tolerated.
A typical cycle runs 20 weeks on, then 0 weeks off before reassessment.
Use the calculator below to convert your target Tirzepatide dose into exact insulin-syringe units.
Reconstitution & storage
A standard 10 mg vial reconstituted with 2 mL of bacteriostatic water yields 5000 mcg/mL. Lyophilized stable at 2–8°C. Refrigerate after reconstitution.
Side effects & considerations
- Nausea, vomiting, diarrhea, constipation
- Decreased appetite (intended)
- Injection-site reactions
- Pancreatitis risk; thyroid C-cell warning
Tirzepatide stacks
- Lean-Mass Preservation — paired with Ipamorelin, CJC-1295. Offset lean-mass loss during caloric deficit. Researchers studying GLP-1-driven weight loss often pair GH secretagogues to model lean-mass preservation. This is not a clinical protocol.
Selected research
- Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) — NEJM, 2022
- Tirzepatide versus Semaglutide Once Weekly in Type 2 Diabetes (SURPASS-2) — NEJM, 2021