Tirzepatide

Tirzepatide is a 39-amino-acid synthetic peptide engineered from the native GIP scaffold. It activates both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. Dual agonism amplifies glucose-dependent insulin secretion, slows gastric emptying, suppresses glucagon, and modulates hypothalamic appetite circuits. The C-20 fatty acid conjugation extends its half-life to roughly 5 days, enabling once-weekly dosing.

Half-life: ≈ 5 days

• Mean weight reduction of 15-22.5% of baseline body weight in 72 weeks (SURMOUNT-1)
• HbA1c reductions of 2.0-2.4 percentage points in type 2 diabetes
• Improvements in blood pressure, triglycerides, and hepatic steatosis markers
• Significant reduction of waist circumference and visceral adipose tissue
• Once-weekly subcutaneous dosing — superior compliance versus daily agents

Clinical protocols start at 2.5 mg subcutaneously once weekly for 4 weeks (titration only, not therapeutic). Doses are then escalated by 2.5 mg every 4 weeks based on tolerance up to a maximum of 15 mg weekly. Research reconstitution: typically 2 ml bacteriostatic water per 10 mg vial, delivering 0.05 ml per 2.5 mg dose with an insulin syringe.

Dosing information is summarised from published clinical and pre-clinical literature for research purposes only and does not constitute medical advice.

• SURMOUNT-1: Tirzepatide once weekly for the treatment of obesity

  New England Journal of Medicine · 2022

  2 539 adults without diabetes randomised to 5, 10, or 15 mg achieved mean weight losses of 15.0%, 19.5%, and 20.9% versus 3.1% on placebo over 72 weeks.

• SURPASS-2: Tirzepatide versus semaglutide once weekly in T2D

  New England Journal of Medicine · 2021

  All tirzepatide doses produced superior HbA1c and weight reductions versus 1 mg semaglutide at 40 weeks.

• Most common adverse events are gastrointestinal: nausea, vomiting, diarrhea, constipation
• Contraindicated in personal or family history of medullary thyroid carcinoma or MEN 2
• Risk of pancreatitis; discontinue if persistent severe abdominal pain
• Slow GI motility may delay absorption of oral medications including hormonal contraceptives
• Not for use in pregnancy or breastfeeding

For research use. Consult a licensed clinician before any human application. Not for use in pregnancy, lactation, or active malignancy without specialist supervision.