Mounjaro 5mg price across UK pharmacies (2026)

If you're checking the Mounjaro 5mg price in the UK, you've likely finished your first four weeks on the 2.5 mg starter pen and want to know what the next step costs. The 5 mg pen is your first proper treatment dose — and the price gap between legitimate UK pharmacies is wide enough that it pays to compare before you reorder.

This guide lays out real 5 mg prices from GPhC-registered pharmacies and CQC-regulated clinics, what drives the difference, and how to keep costs down without stepping outside the legal market.

What the Mounjaro 5mg price looks like in the UK

The 5 mg pen is the dose you move to after the 2.5 mg starter. In the SURMOUNT-1 trial, mean weight loss at 5 mg was around 16% over 72 weeks — so for many people 5 mg is both a stepping stone and, for some, a maintenance dose.

Because it's the same licensed pen everywhere, the only things that change are the pharmacy's dispensing fee, consultation cost and any promotion. Across the providers we track, the 5 mg pen ranges from £154 to £249 per four weeks. Shopping around inside the legal market is where the savings are — not outside it.

Real UK prices for the 5mg pen

Here's how a range of legitimate providers compare for the 5 mg dose. Full per-dose pricing is on our price comparison page.

Prices last checked 01 September 2026. Confirm current pricing on the provider's own site before ordering.

Why the 5mg price varies so much

A £95 gap for the same pen surprises most people. The main drivers are:

• Business model. Large high-street brands (Boots, Numan, Voy) tend to price higher; leaner online pharmacies price keener.
• What's bundled. Needles, prescriber reviews and delivery should be included — some providers fold more support into the price.
• First-order promotions. Most discount codes apply only to the 2.5 mg starter pen, so by 5 mg you're usually paying the ongoing rate.

The takeaway: don't judge a provider on the starter price alone. If you'll be on 5 mg for months, the ongoing 5 mg figure matters far more than a one-off welcome discount.

How to keep your 5mg cost down (legally)

1. Compare the ongoing 5 mg price, not the headline. Use the price table and look specifically at the 5 mg column.
2. Factor in the whole titration path. You may step up to 7.5 mg and beyond, so check those prices too — see our price per pen breakdown.
3. Use a genuine first-order discount at the start. Our recommended provider, The Weight Clinic, takes £35 off your first order with code NEWME, and offers monthly video reviews plus a refund if the prescriber declines you.
4. Check regulation. Every provider in our table is a GPhC-registered pharmacy or CQC-regulated clinic. Anything cheaper with no consultation or ID check is a red flag, not a bargain.
5. Confirm stock. Shortages can nudge prices up — see stock and availability if your dose is hard to find.

Is 5mg the right dose for you?

Dosing isn't a price decision — it's a clinical one. Mounjaro is started low and increased slowly to reduce side effects: 2.5 mg weekly for four weeks, then 5 mg, then raised in 2.5 mg steps (7.5, 10, 12.5) after at least four weeks each, up to a maximum of 15 mg. Your maintenance dose (often 5, 10 or 15 mg) is tailored to how you respond.

Common side effects include nausea, diarrhoea, constipation, vomiting and tiredness. Rare but serious risks include pancreatitis and gallstones. Report any suspected side effect through the MHRA Yellow Card scheme. This article is price and information only — not medical advice.

If you're not yet on Mounjaro, start with our guides on Mounjaro eligibility in the UK and how to start Mounjaro. For the cheapest legal routes overall, see buying Mounjaro online cheap in the UK.

5mg vs the starter and higher doses

The 2.5 mg starter is a four-week introduction, not a treatment dose, so it's the cheapest pen. The 5 mg is your first real dose and typically £20–£40 more than the starter at the same pharmacy. From there, 7.5 mg, 10 mg, 12.5 mg and 15 mg each rise again. Budgeting for the whole path — rather than just the first pen — is the single most useful thing you can do before committing.

Frequently asked questions