GLP-1 & metabolic · FDA-approved T2D (2022) and chronic weight management (2023)
Tirzepatide
Mounjaro, Zepbound, LY3298176
First dual GIP/GLP-1 co-agonist. Approved as Mounjaro and Zepbound. GI effects dominate tolerability.
- Glycaemic control
- Weight (labelled products)
- Catalog fill
- 10 mg
- Typical water
- 2 mL
- Route
- Subcutaneous, once weekly
- Cycle
- Stepwise titration. There is no short 'cycle' in the recovery-peptide sense.
- Approval
- FDA-approved 2022 diabetes, 2023 obesity.
- Status
- Prescription only (Mounjaro / Zepbound).
- Evidence
- SURPASS HbA1c and weight data; obesity trials ~19–21% weight reduction.
- Research score
- 95 / 100
Mechanism
GIP and GLP-1 receptors: insulin, glucagon suppression, slower gastric emptying, central intake regulation. Higher GIP than GLP-1 affinity on this molecule.
Safety file
Generally tolerated. GI side effects are the common ones.
- Nausea
- Diarrhoea
- Vomiting
- Constipation
- Abdominal pain
Reconstitution
2 mL bacteriostatic water into 10 mg gives 5 mg/mL. 2.5 mg is 50 units; 5 mg is 100 units (1 mL).
Research amounts
Once weekly. Stay at each step long enough to see tolerability before moving.
| Step | Amount | Frequency | Notes |
|---|---|---|---|
| Start | 2.5 mg | Weekly | 50 units at 5 mg/mL |
| Step | 5 mg | Weekly | 100 units — full 1 mL at this reconstitution |
| Later research amounts | 7.5–15 mg | Weekly | Use more water or a larger vial so the draw is not past 1 mL |
Storage
- Lyophilized
- −20 °C freezer preferred; a refrigerator is also acceptable. Do not open a cold vial — wait 15–30 minutes so it does not sweat. Avoid freeze–thaw cycling.
- After water
- 2–8 °C, dark, up to 45 days when mixed with bacteriostatic water. Mixed vials stay in their box. Sterile water (no preservative) is single-use.
Worksheet notes
- If a weekly amount needs more than 1 mL, increase the water in the vial rather than stacking syringes.
- Not a substitute for licensed metabolic care.
- Bacteriostatic water: 20–25 °C. Do not refrigerate the diluent.
- Amounts on this sheet are reconstitution math for the vial, not a recommendation.
Full protocol
Titration, schedule, and handling
The complete protocol for Tirzepatide. Where it differs from the worksheet amounts above, the worksheet reflects the NovaEvum vial.
Reconstitution
| Vial | 1 mL water | 2 mL water | 3 mL water |
|---|---|---|---|
| 10 mg | 10 mg/mL | 5 mg/mL | 3.33 mg/mL |
| 30 mg | 30 mg/mL | 15 mg/mL | 10 mg/mL |
With a 30 mg vial, 3 mL of bac water gives a clean 10 mg/mL where every titration step is a round number (2.5 mg is 25 units, 5 mg is 50, 10 mg is 100). Smaller vials take 1 to 2 mL.
- Use bacteriostatic water as the diluent.
- Add the water slowly, letting it run down the inside wall of the vial rather than onto the powder.
- Swirl gently to mix, then leave it to dissolve. Do not shake.
- Give it a few minutes. The finished solution should be clear and colourless.
Protocol
Route: Subcutaneous
Standard titration (once weekly, subcutaneous)
- Weeks 1 to 4: 2.5 mg
- Weeks 5 to 8: 5 mg
- Then step up by 2.5 mg every 4 weeks as needed: 7.5, 10, 12.5, up to 15 mg max
- Recommended maintenance doses are 5, 10, or 15 mg
- The 2.5 mg step is a starter dose, not a maintenance dose
Stop climbing when it is working
- If you are losing weight and feel fine at 5 mg or 7.5 mg, stay there
- Only go up if progress stalls and you are tolerating the current dose
Dosing detail
- Start at 2.5 mg for a full 4 weeks. This dose is for letting your gut adjust, not for weight loss.
- Move to 5 mg at week 5. From there, only increase by 2.5 mg at a time, never more often than every 4 weeks.
- Maintenance lands at 5, 10, or 15 mg depending on response. Plenty of people hold at 5 or 10 mg long term.
- Same day each week. Half-life is about 5 days.
Duration
- A long-run protocol. Titrate over the first 3 to 5 months, then hold your maintenance dose for as long as it keeps working. Stopping tends to bring weight back, so plan your exit.
Notes
- Inject subcutaneously and rotate sites weekly.
- Nausea and early fullness are the common early effects and ease with slow titration.
- Keep protein up and stay hydrated to protect muscle while losing weight.
Storage and handling
- Keep the powdered (lyophilized) vial in a cool, dark place. Refrigerate it for longer-term storage before mixing.
- Once reconstituted and refrigerated at 2–8 °C away from light, use the vial within 90 days.
- Do not freeze a reconstituted vial, and keep it away from heat and sunlight.
- If the solution turns cloudy, develops floating particles, or shows any other sign of degradation, stop using that vial.