NO. 002 · STAGE 2 · Lv. 92 · HP 200
TIRZEPATIDE
Dual-Receptor Metabolic Peptide
ALIASES
Mounjaro, Zepbound, LY3298176, GIP/GLP-1 RA
CLASS
Synthetic peptide · dual GIP/GLP-1 receptor agonist
FORMULA
C225H348N48O68
HALF-LIFE
~5 days
ROUTES
Subcutaneous (FDA-label)
MECHANISM OF ACTION
Dual GLP-1 and GIP receptor agonist. Marketed (under separate human-prescription label) as Mounjaro and Zepbound by Eli Lilly. Once-weekly subcutaneous administration.
EVIDENCE GRADES
SURMOUNT-1 reported -22.5% body-weight change at 15 mg vs -2.4% placebo at 72w. Large RCT, n=2,539.
SURPASS-2 head-to-head vs semaglutide 1 mg: tirzepatide 15 mg -2.30% HbA1c vs -1.86% semaglutide.
Pooled trial improvements in BP, lipids, liver enzymes.
SURMOUNT-MAINTAIN supports continued treatment to maintain reduction; cessation produces regain.
MECHANISM CATEGORIES
RESEARCH CONDITIONS
SAFETY
Side effects
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Pancreatitis (rare, boxed-warning caution)
- Gallbladder disease (rare)
Drug interactions
- Oral contraceptives (delayed gastric emptying may alter absorption)
- Sulfonylureas / insulin (hypoglycemia risk)
Contraindications
- Personal/family history of medullary thyroid carcinoma
- Multiple endocrine neoplasia type 2
REGULATORY STATUS
FDA · Approved as Mounjaro (T2D, May 2022) and Zepbound (chronic weight management, Nov 2023). Compounded versions restricted since FDA shortage declaration lifted Oct 2024.
WADA · Not currently listed on the WADA Prohibited List (2026).
STORAGE
Lyophilized · 2–8 °C, manufacturer-label expiration
Reconstituted · 2–8 °C, 28 days
PEER-REVIEWED EVIDENCE
- Jastreboff AM, Aronne LJ, Ahmad NN, et al.. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med 2022. link →
- Frías JP, Davies MJ, Rosenstock J, et al.. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). N Engl J Med 2021. link →
- Horn DB, Aronne LJ, Wharton S, et al.. Tirzepatide for maintenance of bodyweight reduction in people with obesity in the USA (SURMOUNT-MAINTAIN). Lancet 2026. PMID 42119587. link →
FAQ · 14 QUESTIONS
▶ What is tirzepatide?
Tirzepatide is a 39-amino-acid synthetic peptide that activates the GLP-1 and GIP receptors simultaneously. It is the first dual-incretin agonist marketed in the United States.
▶ What's the difference between Mounjaro and Zepbound?
Same molecule, different label. Mounjaro is FDA-approved for type 2 diabetes (May 2022). Zepbound is the same compound rebranded for chronic weight management (Nov 2023). Different concentrations and titration schedules per label.
▶ Tirzepatide vs semaglutide — which is stronger?
Head-to-head data from SURPASS-2 show tirzepatide 15 mg outperformed semaglutide 1 mg on HbA1c (-2.30% vs -1.86%) and produced larger weight loss. Comparisons at higher semaglutide doses (2.4 mg) are also published; tirzepatide retains an edge on average.
▶ How is tirzepatide dosed?
Per FDA label, tirzepatide is titrated weekly: 2.5 mg starting → 5 mg → up to 15 mg over months. This wiki reproduces the label dose schedule for reference only; any human use should be under qualified clinical supervision.
▶ What is the half-life of tirzepatide?
Approximately five days, enabled by a C20 fatty-acid linker on a modified GIP backbone that drives albumin binding and slow clearance.
▶ Is compounded tirzepatide still legal?
FDA declared the tirzepatide shortage resolved October 2024, restricting compounding under section 503A. Research-grade tirzepatide sold as a chemical reference compound is distinct from compounded human-use formulations and is supplied here for in-vitro research only.
▶ Does tirzepatide cause thyroid cancer?
Class-based rodent C-cell tumor signal led to a boxed warning. Translation to human relevance is debated; current clinical data have not established a causal link, but personal or family history of medullary thyroid carcinoma is a contraindication.
▶ Can tirzepatide be stacked with retatrutide?
No published research supports simultaneous use of multiple incretin agonists. The pathways overlap and combined use is unstudied.
▶ What is the mechanism of tirzepatide?
GLP-1R agonism drives glucose-dependent insulin secretion, glucagon suppression, delayed gastric emptying, and central appetite suppression. GIPR agonism enhances post-prandial insulin and modulates adipocyte lipid handling. Combined activation produces larger absolute weight loss than single-receptor agonism.
▶ How quickly do you lose weight on tirzepatide?
In SURMOUNT-1, mean weight loss followed a curve: ~2-3% by week 4, ~10% by week 24, ~20% by week 72 at the highest dose arm. Individual response varies significantly.
▶ What happens if you stop tirzepatide?
SURMOUNT-4 (re-randomization) showed cessation produces partial weight regain over 52 weeks. Continued treatment is required for maintenance of the loss.
▶ Is tirzepatide banned in sports?
Not currently on the WADA Prohibited List as of 2026. Status reviewable annually.
▶ Can tirzepatide be reconstituted from a research vial?
Yes. Reconstitute lyophilized tirzepatide with USP-grade sterile diluent. The PEPPUDEX /calculator returns the volume-per-dose math given vial size, diluent volume, and target dose.
▶ What's the difference between tirzepatide research-grade and Mounjaro/Zepbound?
The active molecule is the same. Branded human-prescription products are formulated, labeled, and quality-controlled to FDA pharmaceutical standards under separate clinical pathways. Research-grade material is a chemical reference compound for laboratory use only.
APPEARS IN STACKS
SIGNATURE MOVES
Both receptors fire. Slows gastric emptying.
SURMOUNT-1 / NCT04184231.
SOURCED FROM PEPPU LABS
Reference compounds documented on this page are available as research-grade material at Peppu Studio · ≥99% purity · per-batch Certificate of Analysis. For laboratory research use only. No human dose is recommended by this wiki.
▶ LAST UPDATED · 2026-05-19