Calculator for tirzepatide reconstitution and per-administration dosing maths. Tirzepatide is a licensed prescription-only medicine in the United Kingdom (marketed as Mounjaro). Stackcalc.co.uk does not sell tirzepatide and this page is provided for information and research-mathematics purposes only.
For research and educational purposes only. This calculator performs volumetric mathematics on the values you enter; it does not recommend doses or provide medical advice.
Universal peptide & nootropic dose calculator
Standard research pen format: 3 mL total volume, 300 clicks per pen. That’s fixed — so the only thing that changes is how many mg are in your specific pen. mg per click = your pen’s mg ÷ 300.
Vial mode: most research peptide vials are 3 mL borosilicate glass (industry standard — about 99% of compounds ship in this size). Larger compounds like NAD+ or high-mg GHK-Cu sometimes come in 5–10 mL vials. The bacteriostatic water you add must fit inside your physical vial — for a standard 3 mL vial, that’s usually 1–3 mL of BAC water. Tell us the vial’s peptide content (in mg), the BAC water you added, and your target dose — we work out the concentration, the volume to draw, and the syringe units on a U-100 insulin syringe.
Research and educational purposes only. Not medical advice. Not for human consumption. This calculator performs volumetric mathematics on the values you enter; it does not recommend doses. Compounds listed are not licensed as medicines for human use unless stated otherwise.
About Tirzepatide
Tirzepatide is a dual GLP-1/GIP receptor agonist developed by Eli Lilly. It is a licensed prescription medicine in the United Kingdom under the brand name Mounjaro. As a prescription-only medicine, tirzepatide can only be lawfully supplied via licensed pharmacy channels under a valid UK prescription.
Published research literature describes tirzepatide in clinical trials for type 2 diabetes and weight management. The compound’s dual-receptor mechanism (GLP-1 + GIP) distinguishes it from single-agonist compounds like semaglutide.
Typical reconstitution / pen formats
| Format | BAC water | Concentration / mg per click | Volume to draw / clicks | For |
|---|---|---|---|---|
| 10mg pen (prefilled, 3ml/300 clicks) | — | 0.033 mg/click | ≈75 clicks for 2.5mg / ≈150 clicks for 5mg | research-format pen |
| 30mg pen (prefilled, 3ml/300 clicks) | — | 0.10 mg/click | ≈25 clicks for 2.5mg / ≈50 clicks for 5mg | research-format pen |
| 45mg pen (prefilled, 3ml/300 clicks) | — | 0.15 mg/click | ≈17 clicks for 2.5mg / ≈33 clicks for 5mg | research-format pen |
Tirzepatide dosing observed in research literature
Published clinical-trial titration protocols escalate from 2.5mg weekly (starting), through 5mg, 7.5mg, 10mg, 12.5mg, to 15mg weekly maintenance. Titration is typically over 4-week increments to manage tolerability.
These figures are reported here for completeness of the research-literature picture and do not constitute a dosage recommendation.
Half-life and frequency
Tirzepatide has a half-life of approximately 5 days, supporting once-weekly administration. Slightly shorter than semaglutide (≈7 days), longer than daily-dosed compounds.
Storage and shelf life
Licensed pharmacy products have specific storage instructions on the packaging.
Frequently asked questions
Is tirzepatide legal to buy without a prescription in the UK?
No. Tirzepatide is a prescription-only medicine in the UK. Lawful supply requires a valid prescription from a registered pharmacy. Stackcalc.co.uk does not sell tirzepatide.
What is the typical click count on a 30mg tirzepatide pen for a 5mg dose?
30mg ÷ 300 clicks = 0.10mg per click. For 5mg: 5 ÷ 0.10 = 50 clicks. For 2.5mg: 25 clicks.
What’s the difference between tirzepatide and semaglutide?
Both target GLP-1 receptors. Tirzepatide is a DUAL agonist (also targets GIP receptors); semaglutide is a single GLP-1 agonist. Clinical trial data has shown tirzepatide produces higher mean weight reduction in head-to-head comparisons.
Related compounds and stacks
Where to source research-grade Tirzepatide
For UK readers researching Tirzepatide, our partner supplier stocks research-grade preparations. (Partner link to be added after the affiliate arrangement is signed.) We do not sell peptides ourselves and are not responsible for any third-party supplier’s product quality, regulatory compliance, or customer service.
Compliance: Stackcalc.co.uk provides calculator tools and information for research and educational purposes only. We do not sell, supply, or recommend peptides, nootropics, or any other compounds. Content on this site does not constitute medical advice. Always consult a qualified healthcare professional. Not for human consumption.