Cheapest Mounjaro 5mg in the UK: prices compared

Looking for the cheapest Mounjaro 5mg in the UK? You're asking the right question. The 5mg dose is the first proper treatment dose — the one you step up to after your four-week 2.5mg starter — and for many people it's where they'll stay for months. So the 5mg price, not the flashy first-month starter discount, is what really decides how much you'll spend.

Below we've pulled the real ongoing 5mg prices from every regulated UK pharmacy we track (last checked 01 September 2026). No invented figures, no dodgy sellers — just the genuine brand pen, priced pharmacy by pharmacy.

Cheapest Mounjaro 5mg UK: price comparison table

These are the ongoing 5mg prices (per four-week pen). First-month promo codes usually only apply to the 2.5mg starter dose, so what you see here is closer to what you'll actually pay month after month once you've stepped up.

Every provider above is a UK-regulated GPhC pharmacy or a CQC-regulated online doctor service dispensing genuine, brand Mounjaro after an online consultation. You can see the full per-dose breakdown any time on our homepage price table.

Why the 5mg price matters more than the starter deal

Pharmacies love to advertise a cut-price first month. But that headline number is almost always for the 2.5mg starter dose — a four-week introductory step that nobody stays on. Mounjaro dosing starts at 2.5mg for a month, then rises to 5mg, and continues in 2.5mg steps (7.5, 10, 12.5) up to a maximum of 15mg, each held for at least four weeks.

That means 5mg is where your real spending pattern begins. A pharmacy with a tempting £122 starter month can quietly become one of the pricier options once you're on 5mg — so always look past the first-month teaser. Our guide to what a year of Mounjaro really costs shows exactly how the numbers stack up dose by dose.

Is the 5mg dose right for you?

The 5mg dose can be a maintenance dose for some people, or a stepping stone to higher doses for others. In the SURMOUNT-1 trial, people on 5mg lost around 16% of their body weight over 72 weeks, rising to about 21–22% on 10mg and 15mg. Your prescriber decides which dose suits you — this article is about price, not medical advice.

How to get the cheapest 5mg without cutting corners

Saving money on Mounjaro is completely legitimate when you stick to regulated pharmacies. Here's how the savings actually work:

• Compare the ongoing 5mg price, not the starter price. That's the whole point of the table above.
• Use a verified discount code. Many pharmacies knock money off with a code — see our list of Mounjaro discount codes that actually work.
• Watch stock and price movements. Prices shift most weeks; check our cheapest deals this month round-up.
• Don't chase a bargain that looks too good. Anything sold with no prescription, or a mystery "compounded tirzepatide", is a red flag. Read is cheap Mounjaro safe? before you buy anywhere unfamiliar.

For a fully rounded view of what's genuinely available, our list of 6 legitimate ways to pay less for Mounjaro covers codes, pay-as-you-go pharmacies and dose planning.

Our recommended provider for 5mg

We rate The Weight Clinic as our recommended provider. Its 5mg price of £185 is among the lowest, it's a GPhC-registered pharmacy, and it offers £35 off your first order with code NEWME, a refund if the prescriber declines you, and monthly video reviews so someone's actually keeping an eye on your progress rather than just posting a pen.

That combination — competitive ongoing pricing plus proper clinical oversight — is exactly what you want from a weight-loss provider you'll be using for months.

A quick word on side effects and safety

Mounjaro is a prescription-only medicine. The most common side effects are nausea, diarrhoea, constipation, vomiting and tiredness, which is partly why the dose is raised slowly. Rarer but serious risks include pancreatitis and gallstones. If you experience a side effect, report it through the MHRA Yellow Card scheme — it helps keep medicines safe for everyone. A prescriber decides whether Mounjaro is suitable for you; typical private eligibility is a BMI of 30+, or 27+ with a weight-related condition.

Frequently asked questions