Tirzepatide
GLP-1 / GIP Dual AgonistAlso known as: Mounjaro · Zepbound · LY3298176
A once-weekly dual GIP/GLP-1 receptor agonist with superior weight loss efficacy versus GLP-1 monotherapy. FDA approved for T2D & obesity.
Typical Dose
5–15 mg once weekly
Route
Subcutaneous injection (once weekly)
Cycle
Continuous; 20-week escalation to maintenance
Half-life
~5 days
Storage
Reconstituted: 2–8°C, use within 28 days.
Overview
Tirzepatide is a synthetic dual agonist of both glucagon-like peptide-1 (GLP-1) & glucose-dependent insulinotropic polypeptide (GIP) receptors. The addition of GIP agonism — absent from semaglutide — contributes to improved adipose tissue metabolism & appears to reduce the nausea ceiling that limits GLP-1 dose escalation.
SURMOUNT trials demonstrated 20–22% mean body weight reduction at 15 mg/week, exceeding semaglutide's 15% in head-to-head comparisons. Tirzepatide received FDA approval as Mounjaro (T2D, 2022) & Zepbound (obesity, 2023). Compounded tirzepatide is widely circulated since 2024.
Quick Start Guide
Start at 2.5 mg subcutaneously once weekly for 4 weeks.
Escalate by 2.5 mg every 4 weeks to target dose (5–15 mg).
Inject into abdomen, thigh, or upper arm. Rotate sites.
Allow refrigerated solution to reach room temperature before injecting.
Research Indications
Weight loss / obesity
Most EffectiveSURMOUNT-1: 22.5% mean weight loss at 15 mg vs 2.5% placebo. Largest body weight reduction in any approved pharmacotherapy trial.
Type 2 diabetes
Most EffectiveSURPASS trials: HbA1c reductions of 1.9–2.6%. FDA approved at 5, 10, 15 mg.
Research Protocols
Weight loss (standard escalation)
Escalate every 4 weeks; maintain at highest tolerated doseDose
2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg
Frequency
Once weekly SubQ
Route
SubQ abdomen/thigh
Peptide Interactions
Do not combine. Same mechanism class.
Do not combine.
Side Effects & Safety
Common
- Nausea
- Diarrhea
- Vomiting
- Constipation
- Decreased appetite
Uncommon
- Pancreatitis
- Gallbladder disease
- Injection site reactions
- Tachycardia
When to Stop
- Personal/family history of medullary thyroid carcinoma or MEN2
- Suspected pancreatitis
- Signs of allergic reaction
How to Reconstitute
Wipe stopper with alcohol swab.
Inject bacteriostatic water slowly down inner vial wall.
Swirl gently until dissolved (may take 2–3 minutes).
Label & refrigerate. Use within 28 days.
Dosing math: Concentration varies by compounder. Common: 5 mg/mL or 10 mg/mL. Confirm before drawing.
Quality Indicators
Good — use as normal
- Clear, colorless solution
Acceptable
- Very faint tint consistent across batch
Discard immediately
- Cloudiness
- Particulate
- Discoloration
What to Expect
Weeks 1–4 (2.5 mg)
Appetite suppression begins. GI side effects peak in week 2.
Weeks 5–12 (5–7.5 mg)
Significant weight loss begins. GI tolerance usually improves.
Weeks 13–20 (10–15 mg)
Peak weight loss phase. 15–22% of body weight over the full course.
Community Insights
Self-reported. Reflects user experience, not clinical outcomes.
Research References
New England Journal of Medicine · 2022
22.5% mean body weight reduction at 15 mg vs 2.4% placebo at 72 weeks.
doi:10.1056/NEJMoa2206038 →Verify what you have
Information on this page applies to pharmaceutical-grade peptides. Purity & identity of research-grade products vary. Certipep provides independent ESI-TOF-MS & HPLC analysis with a signed analytical report.
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