SunnyPharma provides independent health education for UK patients. The Mounjaro KwikPen used in the UK operates on a fixed-click mechanism — understanding how clicks correspond to doses helps patients use their pen with confidence. This guide gives the complete click reference for all six UK pen strengths, explains the mechanics behind the numbers, and addresses the most common questions about click counting, including the “5th dose” claim.
- Full dose = 60 clicks on every UK KwikPen, regardless of pen strength
- Volume per click: 0.01 mL — constant across all six pen strengths
- Full dose volume: 0.6 mL — always 60 clicks × 0.01 mL
- Each pen contains 4 full doses — Eli Lilly does not endorse a 5th dose
- What changes between pen strengths is the concentration (mg/mL), not the click count
- Partial doses require a prescriber’s instruction — do not adjust clicks without clinical guidance
Mounjaro Click Chart UK — Full Reference Table
The table below covers all six UK Mounjaro KwikPen strengths. The full prescribed dose from any pen is always 60 clicks. The mg-per-click figure changes because each pen has a different concentration of tirzepatide dissolved in the same 0.6 mL volume.
| Pen strength | Full dose (clicks) | Volume per dose | mg per click | Typical use |
|---|---|---|---|---|
| 2.5 mg | 60 clicks | 0.6 mL | ~0.042 mg | Starting dose — weeks 1–4 |
| 5 mg | 60 clicks | 0.6 mL | ~0.083 mg | First escalation — weeks 5–8 |
| 7.5 mg | 60 clicks | 0.6 mL | ~0.125 mg | Mid escalation — weeks 9–12 |
| 10 mg | 60 clicks | 0.6 mL | ~0.167 mg | Higher escalation or maintenance |
| 12.5 mg | 60 clicks | 0.6 mL | ~0.208 mg | Higher escalation or maintenance |
| 15 mg | 60 clicks | 0.6 mL | ~0.250 mg | Maximum licensed dose |
Source: Calculated from Mounjaro UK Summary of Product Characteristics (Eli Lilly, medicines.org.uk). mg-per-click values are approximate (rounded to 3 decimal places). Always follow your prescriber’s dosing instructions — do not adjust your dose by counting clicks without clinical guidance.
This chart is for information only. The click counts above reflect the full prescribed dose for each pen strength. Adjusting your dose by counting clicks is off-label use. Never change your Mounjaro dose without your prescriber’s instruction. If you are unsure how to use your KwikPen, ask your pharmacist for a demonstration.
Why Every Mounjaro Pen Uses 60 Clicks
The 60-click figure is not arbitrary — it comes directly from the KwikPen’s mechanical design. The pen is calibrated to deliver exactly 0.6 mL of solution per full dose. Each click of the dial mechanism moves 0.01 mL of solution. Therefore:
0.6 mL ÷ 0.01 mL per click = 60 clicks
This relationship holds for all six pen strengths because the volume delivered per click is constant. What changes between pen strengths is the concentration — the amount of tirzepatide (in mg) dissolved in each millilitre of solution. A 15 mg pen contains a much higher concentration than a 2.5 mg pen, but both deliver the same 0.6 mL volume when the dial is turned to 60 clicks.
On a U-100 measurement scale (used for insulin and some other injectables, where 100 units = 1 mL), 0.6 mL corresponds to 60 units. This is why some patients and clinicians describe the Mounjaro dose in units rather than clicks — the numbers are the same.
How to Count Mounjaro Clicks Correctly
For the standard full prescribed dose, you do not need to count clicks at all. The UK KwikPen has a mechanical stop — turning the dial until it will not go further delivers exactly one full dose. The clicks are audible and tactile during this process.
Counting becomes relevant only in two situations:
- Partial doses prescribed by your clinician — for example, 2.5 mg from a 5 mg pen during a slow titration protocol. In this case, use the formula below.
- Verifying your dose — some patients count as a reassurance check that the dial has moved fully.
For most patients using the standard titration schedule, the practical instruction is simply: turn the dial until it stops. That is 60 clicks and one full dose.
Partial Dose Formula — Clicks for Non-Standard Doses
If your prescriber has instructed you to take a dose that differs from the pen’s labelled strength — for example, 2.5 mg from a 5 mg pen — use this formula:
(Desired dose in mg ÷ Pen strength in mg) × 60 = Clicks
| Pen strength | Desired dose | Clicks | Notes |
|---|---|---|---|
| 5 mg | 2.5 mg | 30 clicks | Half dose from 5 mg pen |
| 7.5 mg | 5 mg | 40 clicks | Two-thirds dose from 7.5 mg pen |
| 10 mg | 5 mg | 30 clicks | Half dose from 10 mg pen |
| 10 mg | 7.5 mg | 45 clicks | Three-quarters dose from 10 mg pen |
| 15 mg | 10 mg | 40 clicks | Two-thirds dose from 15 mg pen |
Partial dosing from a higher-strength pen is off-label use. Only follow these calculations if your prescriber has specifically instructed a partial dose.
The 5th Dose — What the Manufacturer Says
Each Mounjaro KwikPen is designed and validated to deliver exactly four full doses. After four injections, residual solution remains in the pen — this is a deliberate feature of the device’s mechanical design, not a usable fifth dose.
Eli Lilly does not endorse extracting a 5th dose. The Mounjaro UK Summary of Product Characteristics (SmPC) specifies four doses per pen. For any solution remaining after four doses, the manufacturer states it should be discarded in accordance with local requirements for medicines disposal.
Attempting to extract residual solution carries three specific risks: the concentration in residual liquid may not match the prescribed dose, sterility cannot be confirmed after four uses, and the pen’s mechanical calibration is not validated for extraction beyond four full turns.
The 5th dose claims circulating on social media and some patient forums are not supported by manufacturer guidance. SunnyPharma does not recommend attempting to extract residual solution from a Mounjaro KwikPen.
What to Do If You Lose Count Mid-Injection
If you are using the standard full-dose protocol (turn until the pen stops), losing count does not matter — the mechanical stop ensures you deliver exactly 60 clicks without counting. For partial doses where you are counting manually, if you lose count:
- Do not attempt a second partial injection from the same pen on the same day
- Do not try to compensate by injecting additional clicks
- Contact your prescriber or pharmacist for guidance on what to do next
- Record what happened — the approximate number of clicks counted before you lost track is useful information for your clinician
- Never double-dose — if in doubt about whether a full dose was delivered, treat it as delivered and inject at your next scheduled time
Related UK GLP-1 Guides
Frequently Asked Questions
A full Mounjaro dose is always 60 clicks on the UK KwikPen, regardless of pen strength. Each click delivers 0.01 mL of solution. A full dose is 0.6 mL, which equals exactly 60 clicks. The number of milligrams delivered depends on the concentration of the specific pen.
Mounjaro 2.5 mg is 60 clicks on the 2.5 mg KwikPen — always the full dose from the starting pen. Each click on the 2.5 mg pen delivers approximately 0.042 mg of tirzepatide.
Mounjaro 5 mg is 60 clicks on the 5 mg KwikPen. Each click delivers approximately 0.083 mg. If a prescriber instructs a 2.5 mg dose from a 5 mg pen for slow titration, that is 30 clicks.
Mounjaro 7.5 mg is 60 clicks on the 7.5 mg KwikPen. Each click delivers approximately 0.125 mg of tirzepatide.
Mounjaro 10 mg is 60 clicks on the 10 mg KwikPen. Each click delivers approximately 0.167 mg of tirzepatide.
No. The Mounjaro KwikPen is designed and validated for four full doses. Eli Lilly’s UK Summary of Product Characteristics does not endorse extracting residual solution. Sterility, concentration, and dose accuracy cannot be guaranteed beyond four full doses. Dispose of the pen after four doses in accordance with your pharmacist’s guidance.
Use the formula: (desired dose in mg ÷ pen strength in mg) × 60 = clicks. For example, 2.5 mg from a 5 mg pen = (2.5 ÷ 5) × 60 = 30 clicks. Only use this calculation if your prescriber has specifically instructed a partial dose — never adjust your own dose without clinical guidance.
If using the standard full-dose protocol, the pen’s mechanical stop ensures the correct dose regardless of whether you count. If counting manually for a partial dose and lose count, do not attempt a second injection — contact your prescriber or pharmacist. Never double-dose; if in doubt, treat the injection as delivered and continue to your next scheduled dose.
For a full prescribed dose, no — it is always 60 clicks. For partial doses, the click count changes based on the formula. The concentration per click changes between pen strengths; what stays constant is the volume: 0.01 mL per click, 0.6 mL per full dose.
On the UK KwikPen, 60 clicks corresponds to 60 units on a U-100 scale (100 units = 1 mL). So 60 clicks = 60 units = 0.6 mL = one full prescribed dose. This equivalence holds for all pen strengths because the volume per click is constant at 0.01 mL.
How we reviewed this article:
SunnyPharma follows strict sourcing guidelines and relies on manufacturer prescribing information, MHRA regulatory documents, and GPhC guidance. Click and volume figures are derived from the Mounjaro UK Summary of Product Characteristics (Eli Lilly, medicines.org.uk). Dr. Swiggum’s review covers the clinical content. SunnyPharma does not prescribe or sell medications.
Read our editorial policy →Sources & References
- Eli Lilly — Mounjaro (tirzepatide) UK Summary of Product Characteristics (SmPC): medicines.org.uk
- MHRA — Mounjaro product information and licensing: gov.uk/mhra
- Eli Lilly — Mounjaro KwikPen Patient Leaflet (UK): medicines.org.uk
- General Pharmaceutical Council — Online pharmacy register: pharmacyregulation.org
- NICE Technology Appraisal TA1026 — Tirzepatide for managing overweight and obesity (December 2023): nice.org.uk
- NHS England — Tier 3 weight management services commissioning guidance: england.nhs.uk
- NHS — Yellow Card Scheme (report medicine side effects): yellowcard.mhra.gov.uk