Mounjaro Forms: Pens, Strengths and Other GLP-1 Types (October 2026)

01 · The short answer

What forms does Mounjaro come in?

Mounjaro comes in one form: an injectable pen. Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly.¹ It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

That means there is no tablet, patch, liquid or powder version of tirzepatide to choose between. The choice you actually face is the strength, and that is decided with a prescriber, not picked from a menu. Each pen is a month's supply, with a dose on the same day each week.

Mounjaro sits beside the other main GLP-1 medicines, which differ in how each is taken.

02 · Your decision

Which form is relevant to you?

If you are asking about Mounjaro specifically, the pen is the only form, so the practical questions are strength and supply. Everyone starts at the lowest strength, and a prescriber reviews progress before any increase. Your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99). Every later order is £25 off the standard price.

If you would rather avoid injections altogether, tablets exist for other GLP-1 medicines, but they are different products with their own licences and prescribing rules. They are not a substitute form of Mounjaro. You can read about both options on our weight loss clinic page, or compare the Wegovy pen with Mounjaro before deciding.

Whichever route you take, treatment is a prescription decision: it is supplied only after a free online consultation reviewed by a GPhC-registered prescriber.

03 · The KwikPen explained

What is in a Mounjaro KwikPen?

A KwikPen is a pre-filled, multi-dose injector that holds a month's supply at a single strength. You dial nothing complicated; the pen is set up to deliver the strength printed on it, and each weekly dose comes from the same pen. Follow the pen's instructions and the patient information leaflet for how to prepare and use it.¹³

Once you start using a pen, UK KwikPens are licensed for up to 30 days (not above 30°C) out of the fridge.¹ Unopened pens are kept in the fridge until first use and last until the printed expiry date. For anything outside that, such as a pen left out by mistake, check the leaflet and ask the pharmacy before using it.

Every order we send includes needles, a sharps bin and injection guidance, and the pen travels in temperature-controlled packaging with free next-day tracked delivery. If you are unsure where to inject, our guide to the Mounjaro butt injection question covers injection sites.

04 · Strengths and titration

How do the six strengths fit together?

The strengths are steps on a ladder, not separate products.

Switching strength means swapping the pen; your prescriber guides the pace, with at least 4 weeks on each dose depending on how you respond.

05 · Tirzepatide versus other GLP-1s

How does tirzepatide differ from other GLP-1 forms?

The difference is in what the medicine does, not only how it is delivered. Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1.¹ Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin. This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy/Ozempic).

In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet. Treatment works alongside diet and increased activity, not instead of them, and individual results vary.

06 · Forms to avoid

Which "forms" of tirzepatide are not genuine?

Anything that is not a Mounjaro KwikPen dispensed by a registered pharmacy should be treated with caution. Sellers advertise powders, vials, "research" products and cheap copies, but none of these is the licensed medicine. The MHRA publishes counterfeit medicine alerts and runs the Yellow Card scheme for reporting suspected problems.⁷

Warning signs include a seller offering to supply without a consultation or prescription, dramatic weight-loss claims, and prices far outside the normal range. Across the UK pharmacies we track, Mounjaro pens ranged from £143.96 to £339.00 per month as of 10 October 2026, depending on dose and provider.

We supply through official LillyDirect supply, so you receive genuine KwikPens direct from Eli Lilly's UK distribution. Our registration can be checked on the GPhC register (9012878).

For more on copies, read our pages on a Mounjaro dupe, a Mounjaro biosimilar and the so-called natural forms of GLP-1. Natural alternatives are low-cost supplements with no clinical oversight and are not equivalent to a prescription medicine.

07 · Stopping and clearance

What happens when you stop using the pen?

You can stop at any time, and the medicine clears from your body slowly. Tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹

Mounjaro manages weight; it does not cure the biology behind it. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average. Stopping should always be planned with your prescriber, with diet and activity habits ready to carry the load.¹⁴ Keep up the eating and activity habits you built while treated. Our prescribing team offers ongoing monthly reviews, and repeat orders re-check suitability, with no auto-shipping.

If anything new worries you, such as jaw clenching, speak to your prescriber and report it through the Yellow Card scheme.¹⁹

08 · NHS and private access

Is the pen form available on the NHS?

Mounjaro is available on the NHS, but access is being phased in over several years.⁶ NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions).⁴ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.

The form is the same either way: the KwikPen. If you go privately, the NHS prescription charge of £9.90 does not apply, and the price shown on our site is the price paid, with no consultation fee. Delivery is free next-day, with Saturday delivery at £14.99. Orders placed by 3pm are dispatched the same day.