How Many ml in a 10mg Mounjaro Pen? (October 2026)

01 · The answer

How many ml are in a 10mg Mounjaro pen?

A 10mg Mounjaro KwikPen contains four weekly doses of 10mg each. You dial the dose number in the window and the pen will not let you dial past the medicine left inside.¹

The same pattern applies across the range. Mounjaro comes in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹ The strength tells you how much tirzepatide is in each weekly dose.

02 · Cost

What a 10mg pen costs

One 10mg pen is four weeks of treatment. At the standard price that is £290.99 per month, or £72.75 per week. A new customer's first order at any dose is £40 less with code FIRST40, including people switching to us at 10mg. Every later order gets an automatic £25 off the standard price (code DOSE25).

The price shown is the price paid, and the consultation is free. Stock is in stock across all six doses, and we supply genuine pens through official LillyDirect supply, sourced directly from Eli Lilly. You can see live prices for every strength on the Mounjaro pen prices and consultation page.

If you are new to Mounjaro, your first pen is 2.5mg, because everyone starts there. A first 2.5mg pen on a new customer's first order is £129.99 with code FIRST40 (standard price £169.99).

03 · Ordering

How ordering works

• Free online consultation: a short health questionnaire, no charge and no obligation.
• Prescriber review: reviewed by a GPhC-registered prescriber. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• Dispatch and delivery: dispensed by our registered pharmacy, with same-day dispatch when ordered by 3pm and free next-day tracked delivery in temperature-controlled packaging.

You can start your free consultation whenever you are ready. Needles, a sharps bin and injection guidance come with every order.

Related guides: Mounjaro Injection 2.5 mg Price and 0.6 ml mounjaro.

04 · Dialling the dose

Why you dial a number, not a volume

You set the dose on a KwikPen by turning the dose knob until the correct dose shows in the window. You confirm it by the number shown, never by counting clicks.¹ If you have wondered about the mechanics, how many turns on a Mounjaro pen explains what to expect when you dial.

The pen will not let you dial past the medicine left inside. If the window will not turn to a full dose, the pen does not contain enough for one and should not be used for a partial injection.¹³

The reliable check is always the number in the window.

05 · Syringes and units

Why not convert ml to syringe units?

You should not convert the pen volume into syringe units, because the KwikPen is not designed to have medicine drawn out of it. The licensed way to take Mounjaro is to dial the dose and inject from the pen.¹³ Our explainer on 0.6 ml Mounjaro in units covers why people ask, and why we recommend sticking with the pen as supplied.

"Microdosing", meaning smaller or more spread-out doses than the pen is designed to deliver, is not licensed. It is not supported by the pen's design and not endorsed by any UK regulator. Altering doses outside the licence means unknown dosing accuracy and no safety data.

If a full dose feels like too much, the licensed route is to talk to your prescriber. They can hold a dose for longer or step down within the licence if side effects are the concern.¹

06 · Doses per pen

How many injections does one pen give?

Each KwikPen contains four weekly doses, so one pen lasts four weeks.¹ That holds at every strength, including 10mg. For more detail, read how many doses are in a 10mg Mounjaro pen.

Treat the pen as four separate weekly injections, one per week on the same day.

07 · Where 10mg fits

Where 10mg fits on the dose ladder

Everyone starts on 2.5mg once a week. After at least 4 weeks the dose rises to 5mg, then can step up by 2.5mg at minimum 4-week intervals (7.5mg, 10mg, 12.5mg) to a maximum of 15mg weekly, depending on response and tolerability.¹ Many people settle at 5mg, 10mg or 15mg. Higher is not automatically better, and your prescriber guides the pace.

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.² At 72 weeks, 89% of participants on 10mg had lost at least 5% of their body weight, and half had lost at least 20%.²

These are trial averages, and individual results vary. Treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.

08 · Storing the pen

Storing and using your pen

Keep Mounjaro pens in a fridge at 2–8°C and never freeze them. Once in use, a pen can be kept out of the fridge not above 30°C for up to 30 days, after which it should be discarded.¹ Keep the cap on to protect the pen from light, and never use a pen that has been frozen.

Unopened pens should stay in the fridge and keep until the expiry date printed on the box. If an unopened pen has been out of the fridge, check with the pharmacy before using it rather than relying on a remembered day limit.¹³

Inject once a week under the skin, on the same day each week, at any time of day, with or without food. Use the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection, and rotate the site each time.¹

09 · Missed doses

What if you miss or move a dose?

If you miss a dose, take it as soon as you can within 4 days (96 hours) of the scheduled time, then carry on as usual. If more than 4 days have passed, skip it and take the next dose on your normal day. Never take two doses within 3 days of each other.¹

You can change your injection day if at least 3 days (72 hours) have passed since your last dose.¹ Whatever happens, you still dial the full number for your strength. Never try to adjust the dose by volume to make up for a missed injection.

10 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹