Almost every Mounjaro (tirzepatide) provider dangles an intro deal at you: "£75 off", "£40 off new customers", "first order half price". They work — a discount is a real saving. But an intro price is designed to win your first order, not your sixth. So the honest question isn't "which offer is biggest?" It's "which offer still looks good once the discount wears off?" We ran that maths on all 14 first-month deals live across the regulated UK market in July 2026.
Here's the trap in one sentence: the loudest discount is often bolted onto the dearest ongoing price. A £75-off headline can leave you paying more from month two than a £26-off one. This article ranks the intro offers the way you should actually judge them — by what your first two pens cost together, and by how hard the price jumps the moment the promo ends.
The biggest first-month discount in the UK is Voy at £75 off — but its ongoing 5 mg pen is £244, so your bill leaps £105 in month two. The best-value intro offers on a two-pen basis are Chemist4U and The Weight Clinic, tied at £310 for your starter plus your first 5 mg pen. Rule of thumb: a small discount on a low ongoing price beats a huge discount on a high one, every time.
How to tell a real Mounjaro offer from discount bait
A first-month offer only ever touches one box — the 2.5 mg starter pen you hold for four weeks before stepping up to 5 mg. From your second order onwards you pay the standard, undiscounted price. So an intro deal has exactly two numbers worth knowing:
- The two-pen total. Your discounted starter pen plus your first full-price 5 mg pen. This is the fairest way to compare offers, because it captures the discount and the price you inherit when it ends.
- The month-two jump. How much your monthly bill rises the moment the promo expires. A £20 jump is easy to swallow; a £105 jump is a nasty surprise if nobody warned you.
Judge every "£X off" headline against those two figures and the discount bait sorts itself out. The table below does exactly that for the ten strongest intro deals in the market.
Every UK Mounjaro first-month offer, ranked by real value
These are the ten best-value first-month deals we track, sorted by two-pen total (discounted starter + first ongoing pen). All figures are four weekly doses, last checked 4 July 2026.
| Provider | Intro deal (2.5 mg) | Discount | Ongoing 5 mg | Two-pen total | Month-2 jump |
|---|---|---|---|---|---|
| The Weight Clinic ★ Our pick | £125.00 code NEWME | £35 off | £185.00 | £310.00 | +£60 |
| Chemist4U | £122.00 code NEW26 | £26 off | £188.00 | £310.00 | +£66 |
| Pharmacy2U | £124.99 first-order deal | £45 off | £189.99 | £314.98 | +£65 |
| Oxford Online Pharmacy | £128.96 code W2TM539S | £20 off | £188.96 | £317.92 | +£60 |
| ZAVA | £129.99 code WZUK40 | £40 off | £187.99 | £317.98 | +£58 |
| ASDA Online Doctor | £138.97 code WNLC10A | £10 off | £188.97 | £327.94 | +£50 |
| Cloud Pharmacy | £154.99 code NEWME10 | £10 off | £174.99 | £329.98 | +£20 |
| MedExpress | £139.99 new-customer deal | £40 off | £189.99 | £329.98 | +£50 |
| LloydsPharmacy Online Doctor | £149.99 code START30 | £30 off | £189.99 | £339.98 | +£40 |
| Voy | £139.00 first-month deal | £75 off | £244.00 | £383.00 | +£105 |
Prices last checked 4 July 2026. All providers are GPhC-registered pharmacies or CQC-regulated clinics; this is price information, not an offer of supply. Confirm the current offer and code on the provider's own site before ordering.
Read the last two columns and the story jumps out. Voy has by far the biggest headline discount (£75 off) yet lands second-from-bottom on value, because its ongoing pen is £244 — the month-two jump is a brutal £105. Chemist4U's discount is a third of that size (£26 off) but it tops the value table, because its ongoing price is £188. The discount is the bait; the ongoing price is the hook. For the full spread of why the same pen costs so differently between pharmacies, see why Mounjaro prices vary between UK pharmacies.
Which first-month offers are actually worth taking?
Group the 14 live deals by what they really do for you and three buckets appear:
- Genuine value. Chemist4U (£310 two-pen) and The Weight Clinic (£310) lead, with Pharmacy2U (£314.98), Oxford Online Pharmacy (£317.92) and ZAVA (£317.98) close behind. Modest-to-decent discounts sitting on low ongoing prices — these hold their value into month two and beyond.
- Soft landing. Cloud Pharmacy's discount is only £10, but its ongoing 5 mg pen is £174.99 — the lowest on the grid — so its month-two jump is just £20. Not the cheapest first box, but the gentlest step up, which suits people who dislike surprises on the second bill.
- Discount bait. Voy (£75 off but +£105 in month two) and Second Nature (£50 off, ongoing £259, +£80) win the headline and lose the year. Big number on the front, big number on the back.
The Weight Clinic is the intro offer we'd take. Code NEWME drops the 2.5 mg starter pen from £160 to £125 — a £35 saving — and its ongoing 5 mg pen is £185, so the two-pen total ties for cheapest on the whole grid at £310. Crucially the month-two jump is a manageable £60, not a cliff edge. It's a GPhC-registered pharmacy, bundles needles and next-day delivery, runs monthly video reviews with a clinician, and refunds you if a prescriber declines to prescribe. That's a real offer, not discount bait.
Getting the most out of a first-month deal
A few things worth knowing before you claim an intro offer:
- Look past the front page. The advertised figure is nearly always the discounted starter pen. Find the ongoing 5 mg price before you decide — that's the number you'll live with. Our Mounjaro price comparison by dose lays every ongoing strength side by side.
- You can switch after month one. Each order is a fresh prescription assessment, so nothing stops you taking a cheap first month at one pharmacy and moving to a lower ongoing price elsewhere. It's a little admin for a real saving.
- A code isn't approval. A discount only changes the price, never your eligibility. Mounjaro is prescription-only; a qualified prescriber decides whether it suits you. Reputable providers refund you if they can't prescribe.
- Mind subscriptions. A few intro deals are the front door to a monthly plan. We weighed that trade-off in Mounjaro subscription vs one-off buying.
- An offer far below the market isn't an offer. If an "intro price" undercuts the regulated field by a wide margin, it's almost certainly an unregulated or "compounded" seller. We never list those — tirzepatide bought outside GPhC/CQC channels is genuinely dangerous.
Once your intro month is over, the cheapest ongoing prices are a separate question — we rank those in the cheapest Mounjaro UK provider ranking, and the always-sorted master grid lives on our homepage price table.
Mounjaro first-month offers FAQ
Are Mounjaro first-month offers a one-time discount?
Almost always, yes. The codes and new-customer prices we track apply to your first order only, usually the 2.5 mg starter pen. From month two you pay the standard price, which is why we always check the ongoing 5 mg cost before recommending any intro deal.
Which provider has the cheapest Mounjaro first month?
On headline price, Chemist4U (£122 with NEW26) is the lowest first-month figure on our grid, with The Weight Clinic just behind at £125 (NEWME). But on a two-pen basis — your starter plus your first 5 mg pen — Chemist4U and The Weight Clinic tie at £310, which is the fairer way to compare.
Is the biggest discount always the best deal?
No. Voy has the largest single-pen discount (£75 off), but its ongoing 5 mg pen is £244 and your monthly cost jumps £105 after month one. A smaller discount attached to a cheaper ongoing price usually works out better over a full course of treatment.
Do I have to keep buying from the pharmacy that gave me the first-month deal?
No — you can move providers between orders, as each is a fresh prescription assessment. Some people take a cheap first month at one pharmacy, then switch to a lower ongoing price elsewhere.
Is a first-month offer a guarantee I'll be approved?
No. A discount code only affects price, never eligibility. Mounjaro is a prescription-only medicine; whether it's suitable for you is decided by a qualified prescriber after an assessment. Reputable providers refund you if you're assessed as unsuitable, but no one can promise approval.
The intro offer we'd actually claim: The Weight Clinic
A bigger discount elsewhere might tempt you, but the offer that still looks good in month two is The Weight Clinic's: £125 for the 2.5 mg starter pen with code NEWME (down from £160), a low £185 ongoing pen so the two-pen total ties for cheapest at £310, plus needles and next-day delivery included, monthly video reviews with a clinician, and a refund if a prescriber decides it isn't right for you. Confirm the current offer on their site before ordering.
Mounjaro is a prescription-only medicine and isn't suitable for everyone. This is price information, not medical advice.