Tirzepatide
FDA APPROVEDDual GIP/GLP-1 receptor agonist | Weight loss & diabetes
By the INFOPEPTIDOS editorial team · content based on scientific literature.
Updated: August 2026 · Based on the SURMOUNT and SURPASS trials.
Key points
- What it is: dual GIP and GLP-1 receptor agonist (marketed as Mounjaro and Zepbound).
- Main use: weight loss and type 2 diabetes.
- Typical dose: 2.5 → 15 mg weekly, subcutaneous injection, with gradual escalation.
- Key result: ~21–22% weight loss in the SURMOUNT trials.
- Common effects: nausea, diarrhea and digestive discomfort (dose-dependent).
- Comparison: dual action; more potent than semaglutide (mono) and less than retatrutide (triple).
- Status: FDA-approved for weight (Zepbound) and diabetes (Mounjaro).
Technical data: Molecular formula C225H348N48O68 · Molecular weight 4813 g/mol. Source: PubChem.
Overview
What is Tirzepatide?
Tirzepatide is a dual agonist of the GIP and GLP-1 receptors, approved by the FDA for both type 2 diabetes and chronic weight management (Mounjaro, Zepbound). It has shown outstanding results compared with single-receptor agonists.
Key benefits
Notable weight loss (15-22% of body weight), better diabetes control, lower cardiovascular risk, greater insulin sensitivity, appetite suppression and preservation of muscle mass.
Mechanism of action
Dual agonist of the GIP and GLP-1 receptors: glucose-dependent insulin stimulation, delayed gastric emptying, glucagon suppression and central satiety signaling through hypothalamic pathways.
Quick start guide
Dosing protocol (weekly titration)
| Phase | Weeks | Weekly dose | Goal |
|---|---|---|---|
| Start | 1–4 | 2.5 mg | Adaptation; minimizes nausea |
| Titration 1 | 5–8 | 5 mg | Gradual increase |
| Titration 2 | 9–12 | 7.5 mg | Progressive increase |
| Titration 3 | 13–16 | 10 mg | Approaching target dose |
| Maintenance | 17+ | 12.5–15 mg (max.) | Maintenance dose |
Subcutaneous route, once a week, increasing the dose every 4 weeks. The exact dose must be set by a healthcare professional.
Reconstitution: units in the syringe
Example with a 20 mg vial + 2 ml of bacteriostatic water → a 10 mg/ml solution. On a U-100 insulin syringe (100 units = 1 ml):
| Dose | Volume | Units (U-100) |
|---|---|---|
| 2.5 mg | 0.25 ml | 25 U |
| 5 mg | 0.50 ml | 50 U |
| 7.5 mg | 0.75 ml | 75 U |
| 10 mg | 1.00 ml | 100 U |
Is your vial or water different? Calculate the exact units below.
🧮 Calculate your exact syringe dose →Retatrutide vs Tirzepatide vs Semaglutide
| Semaglutide | Tirzepatide | Retatrutide | |
|---|---|---|---|
| Receptors | GLP-1 | GLP-1 + GIP | GLP-1 + GIP + glucagon |
| Type | Mono | Dual | Triple |
| Weight loss (max. in trials) | ~15% | ~21–22% | ~24–28% |
| Frequency | 1×/week | 1×/week | 1×/week |
| FDA status | Approved | Approved | Investigational |
⚠️ Who should NOT use it
- Personal or family history of medullary thyroid carcinoma or MEN 2 syndrome.
- History of pancreatitis.
- Pregnancy or breastfeeding.
- Always under the supervision of a healthcare professional.
What to expect
- Appetite reduction within the first 1-3 days after injection.
- Mild to moderate nausea during the first 2-4 weeks (usually improves noticeably).
- Loss of 0.5-1.5 kg per week during the active weight-loss phase.
- Better blood sugar control within 1-2 weeks in people with diabetes.
- Noticeable reduction in cravings and greater satisfaction with smaller portions.
- Greater satiety and meal satisfaction for 6-7 days per injection.
- Possible fatigue during the first weeks of adaptation.
- Peak weight-loss effects usually between weeks 16-24.
- Improved energy levels after the initial adaptation period.
Side effects & safety
- Start with the lowest dose (2.5 mg) and increase gradually every 4 weeks to minimize side effects.
- Contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2 syndrome.
- Watch for signs of acute pancreatitis (severe, persistent abdominal pain radiating to the back).
- Significant nausea is common at first but usually improves — stay hydrated and eat smaller meals.
- Requires a prescription and medical supervision — not available over the counter.
- Store in the fridge between 2-8 °C, never freeze or shake vigorously.
- May require adjusting other diabetes medications to avoid hypoglycemia.
- Severe allergic reaction: rash, itching, swelling of the face, lips or throat, or difficulty breathing.
- Severe, persistent abdominal pain radiating to the back (possible pancreatitis).
- Persistent vomiting or diarrhea with signs of dehydration.
- Lump or swelling in the neck, hoarseness or difficulty swallowing.
- Pain in the upper right abdomen or yellowing of the skin (possible gallbladder problem).
- Symptoms of severe hypoglycemia: confusion, sweating, tremors or fainting.
- Vision changes or worsening of diabetic retinopathy.
- Racing heartbeat or persistent palpitations.
- If you are pregnant or plan to be soon.
Frequently asked questions
What is Tirzepatide?
Tirzepatide is a dual agonist of the GIP and GLP-1 receptors, approved by the FDA for type 2 diabetes and weight management (Mounjaro, Zepbound).
What is Tirzepatide used for?
It is used for weight loss and glucose control, with outstanding results compared with single-receptor agonists.
How does Tirzepatide work?
It activates the GIP and GLP-1 receptors at the same time: it stimulates glucose-dependent insulin, slows gastric emptying and reduces appetite.
How long does Tirzepatide take to work?
Appetite reduction appears in the first days or weeks; weight loss is progressive and peak effects are seen after months.
What is the usual Tirzepatide dose?
It starts at 2.5 mg weekly and is increased every 4 weeks up to the target dose (up to 15 mg). The schedule is decided by a professional.
How is Tirzepatide administered?
By subcutaneous injection once a week in the abdomen, thigh or arm.
How much weight can you lose with Tirzepatide?
In clinical trials, average reductions of 15-22% of body weight were observed, depending on the dose and the person.
How is Tirzepatide stored?
Refrigerated between 2 and 8 °C. More information in the storage guide.
What are the side effects of Tirzepatide?
Mainly digestive: nausea, diarrhea, vomiting and constipation, especially when increasing the dose.
What is the difference between Tirzepatide and Semaglutide?
Tirzepatide acts on two receptors (GIP and GLP-1) and semaglutide on one (GLP-1); the former usually shows greater average weight loss.
Is Tirzepatide approved?
Yes, it is approved by the FDA for type 2 diabetes and weight management.
Who should not use Tirzepatide?
Contraindicated with a history of medullary thyroid carcinoma or MEN 2, and during pregnancy.
Research areas
- Weight loss
- Type 2 diabetes control
- Appetite reduction
- Metabolic health
- Blood glucose control
Related peptides
- Semaglutide — GLP-1 receptor agonist for weight and diabetes.
- Retatrutide — Triple GLP-1/GIP/glucagon agonist in research.
- Tesamorelin — GHRH analog researched for visceral fat.
Related articles
Related topics
- Tirzepatide for weight loss
- Tirzepatide and diabetes
- Tirzepatide dose
- Tirzepatide side effects
- Tirzepatide vs Semaglutide
- Tirzepatide Mounjaro and Zepbound
Summary
What it is: Dual agonist of the GIP and GLP-1 receptors (Mounjaro, Zepbound).
How it is researched: Weekly subcutaneous injection; 2.5 to 15 mg.
Key features: Reduces appetite and glucose; average 15-22% loss. FDA-approved.
Related peptides: Semaglutide, Retatrutide and Tesamorelin.
References
- Rodriguez PJ et al. (2024). Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity. JAMA Intern Med. PubMed · DOI
- Zhao L et al. (2024). Tirzepatide for Weight Reduction in Chinese Adults With Obesity: The SURMOUNT-CN Randomized Clinical Trial. JAMA. PubMed · DOI
- France NL et al. (2024). Tirzepatide: A Review in Type 2 Diabetes. Drugs. PubMed · DOI
- Loomba R et al. (2024). Tirzepatide for Metabolic Dysfunction-Associated Steatohepatitis with Liver Fibrosis. N Engl J Med. PubMed · DOI
Studies compiled from PubMed for informational purposes; many are preclinical or research-stage and do not constitute medical advice.