Tirzepatide
Also known as: Mounjaro · Zepbound · LY3298176 · GLP-1/GIP dual agonist
Tirzepatide is a 'twincretin' that simultaneously activates GIPR (glucose-dependent insulinotropic polypeptide receptor) and GLP-1R with equal potency. GIPR activation enhances insulin secretion in a glucose-dependent manner, reduces glucagon, and may directly reduce adipocyte lipid accumulation. GLP-1R activation suppresses appetite via...
What It Is
Tirzepatide is a 'twincretin' that simultaneously activates GIPR (glucose-dependent insulinotropic polypeptide receptor) and GLP-1R with equal potency. GIPR activation enhances insulin secretion in a glucose-dependent manner, reduces glucagon, and may directly reduce adipocyte lipid accumulation. GLP-1R activation suppresses appetite via hypothalamic signaling, slows gastric emptying, stimulates insulin, and reduces glucagon. Together, these produce superior glycemic control and weight loss compared to GLP-1 agonists alone (e.g., semaglutide). The C20 fatty diacid chain enables albumin binding for once-weekly administration.
Supplies Needed
Reconstitution for research use
Subcutaneous injection
Sterilization
Storage
Store at -20C for research peptide. FDA pens: refrigerate at 2-8C.
Refrigerate at 2-8C; use within 30 days.
This information is provided for educational and research purposes only. Not approved for human consumption by the FDA or any regulatory body. Always consult a qualified medical professional.
Dosing Protocols
Timing: Same day each week; any time of day. Starting dose per FDA labeling; titrate up at 4-week intervals to manage GI side effects
↓ Apply these values to the reconstitution calculatorTiming: Same day each week. Titrate: 2.5 -> 5 -> 7.5 -> 10 mg at 4-week intervals. Most patients achieve good weight loss at 5-10 mg.
↓ Apply these values to the reconstitution calculatorTiming: Same day each week. Maximum FDA approved dose (15 mg for Zepbound); 15 mg produced ~22% body weight reduction in SURMOUNT-1 trial
↓ Apply these values to the reconstitution calculatorWeekly Timeline
| Week | Expected Effects |
|---|---|
| Week 4 | Significant appetite reduction; initial weight loss 2-4 kg; GI side effects peaking then improving |
| Week 12 | 5-8% body weight loss; improved blood glucose; reduced cravings |
| Week 24 | 10-15% body weight loss; significant metabolic improvements; reduced medication requirements for T2D |
| Week 52 | Maximum weight loss (~15-22% depending on dose); sustained glycemic control; cardiovascular risk reduction |
Reconstitution Calculator
1 unit on U-100 syringe = 0.01 mL · Always label your vial after reconstitution
Injection Technique & Reconstitution
- Note: FDA-approved Mounjaro/Zepbound comes pre-mixed in auto-injector pens
- For research tirzepatide: Remove flip-top cap from the vial
- Swab rubber stopper with alcohol swab
- Draw appropriate volume of bacteriostatic water
- Inject slowly down the vial wall - do not spray on powder
- Gently swirl until dissolved
- Label with reconstitution date; refrigerate at 2-8C
Use our free peptide reconstitution calculator to get the exact syringe units for your vial size and dose.
Mechanism of Action
Tirzepatide is a 'twincretin' that simultaneously activates GIPR (glucose-dependent insulinotropic polypeptide receptor) and GLP-1R with equal potency. GIPR activation enhances insulin secretion in a glucose-dependent manner, reduces glucagon, and may directly reduce adipocyte lipid accumulation. GLP-1R activation suppresses appetite via hypothalamic signaling, slows gastric emptying, stimulates insulin, and reduces glucagon. Together, these produce superior glycemic control and weight loss compared to GLP-1 agonists alone (e.g., semaglutide). The C20 fatty diacid chain enables albumin binding for once-weekly administration.
Key Research Papers
Pivotal Phase 3 trial showing 22.5% mean weight loss with 15 mg tirzepatide at 72 weeks vs 2.4% placebo in adults with obesity without type 2 diabetes.
View on PubMed →Head-to-head trial demonstrating superior A1C reduction and weight loss with tirzepatide vs semaglutide 1 mg in T2D patients.
View on PubMed →Stacks Well With
BPC-157 helps manage GI side effects from tirzepatide by protecting the gut mucosa and reducing nausea and motility disturbances.
Add NNMT inhibition for metabolic complementarity - tirzepatide handles appetite suppression while 5-Amino-1MQ enhances fat oxidation via NAD+ pathway.
Frequently Asked Questions
Tirzepatide is FDA-approved as Mounjaro for type 2 diabetes and Zepbound for obesity. It is a once-weekly injectable dual GIP/GLP-1 receptor agonist that produces ~20-22% weight loss at the highest dose.
In the SURMOUNT-1 clinical trial, participants on 15 mg tirzepatide lost an average of 22.5% of body weight over 72 weeks. This is greater than any other approved weight loss medication to date (as of 2024).
Head-to-head trials (SURMOUNT-5) show tirzepatide produces significantly greater weight loss than semaglutide 2.4 mg. However, both are effective. Tirzepatide's dual mechanism (GIP+GLP-1) appears to have additive benefits over GLP-1 alone.
Legal Status by Region
This information is provided for educational and research purposes only. Not approved for human consumption by the FDA or any regulatory body. Always consult a qualified medical professional.