The hidden costs of weight-loss injections (and how to avoid them)
The number on the advert is almost never the number you pay. When people search the weight loss injection hidden costs question, they have usually spotted the gap already: a headline first-month price that looked cheap, then a second invoice that landed 40% higher. This report itemises where the money actually goes — promo cliffs, dose climbs, delivery fees and subscription tie-ins — using real figures from our live price board of 24 regulated UK pharmacies, checked on 4 July 2026.
Hidden cost 1: the promo cliff
This is the one that catches most people. Nearly every provider on our board advertises a discounted first month — a promo code knocks money off the starter dose. It is a genuine saving, but it lasts exactly one order. From your second box onward you pay the ongoing rate, which is higher.
The size of the cliff varies wildly. On Mounjaro's 2.5 mg starter dose, the median first-month discount across our board is £28.50. But the spread is the story: one provider discounts the starter by £75, so a £139 first month becomes £214 the moment the promo lapses. The ongoing price was always the real price — but if you budgeted off the advert, you budgeted wrong.
The fix: ignore the promo when you compare. Sort by ongoing price, treat the discount as a one-off bonus, and never let a big month-one number decide a medicine you may take for a year. We show promo and ongoing side by side on the board so the cliff is visible before you climb it.
Hidden cost 2: the dose climb
Weight-loss injections are not a flat monthly fee. Both Mounjaro and Wegovy start on a low introductory dose and step up over months — that is how they are meant to be taken, to reduce side effects. Price climbs with the dose, so the starter price you saw is the cheapest month you will ever pay.
Mounjaro begins at a 2.5 mg starter (a four-week introductory dose, not a treatment dose), then moves to 5 mg and can climb in 2.5 mg steps to a 15 mg maximum. Each rung typically costs more. On our recommended provider, The Weight Clinic, the ladder runs like this:
| Mounjaro dose | First-month price | Ongoing / 4 wks | Stage |
|---|---|---|---|
| 2.5 mgstarter | £125.00 | £160.00 | Introductory · 4 weeks |
| 5 mgfirst maintenance | — | £185.00 | Treatment dose |
| 7.5 mg | — | £240.00 | Step-up |
| 10 mg | — | £260.00 | Step-up |
| 12.5 mg | — | £275.00 | Step-up |
| 15 mgmaximum | — | £295.00 | Top dose |
Mounjaro dose ladder, The Weight Clinic, ongoing prices as checked 4 July 2026. First-month £125 reflects the NEWME code on the 2.5 mg starter. Your prescriber decides your dose and pace; not everyone reaches or needs the top dose.
Read that top-to-bottom and the hidden cost is obvious. The £125 you paid to start is £170 less than the £295 on the maximum dose. Between a promo starter and a full maintenance month, the jump on this provider is £60 — before any further climb. None of this is hidden by the pharmacy; it is hidden by the way people compare, fixing on the first month and assuming it holds.
The fix: budget for your likely maintenance dose, not your starter. We track the cheapest provider at every single dose in our cheapest GLP-1 by dose tracker, so you can see where the cost curve is gentlest for the dose you settle on.
Hidden cost 3: delivery and cold-chain fees
These injections need refrigerated, tracked delivery, and not every provider folds that into the headline price. Of the 24 pharmacies on our board, 18 offer free delivery in some form. The other six charge — usually a few pounds per order, sometimes gated behind a minimum spend.
Delivery fees on our board run from £2.90 to £8.95 per order. Small in isolation — but this is a monthly medicine, so a £5.95 next-day charge is roughly £71 a year that never appeared on the price you compared. Some providers advertise "free delivery" only over a spend threshold (for example, free over £39 or £45), and a couple charge extra for a next-day upgrade on top of a free standard option.
The fix: read the delivery line, not just the price. A provider that is £3 cheaper per box but charges £5.95 postage is more expensive in reality.
The Weight Clinic — the price you see is close to the price you pay
The Weight Clinic is our pick partly because its costs are legible: next-day delivery with needles included, a free consultation, and a monthly video review with a qualified prescriber rather than a one-off questionnaire. If the prescriber declines to prescribe, you get a refund. The NEWME code takes £35 off your first order — a genuine one-month saving on top of an ongoing price you can see up front.
Hidden cost 4: subscription lock-in
Some providers wrap the medicine in a subscription or programme rather than selling it order by order. That can be good value if you use the coaching, the app and the dietitian support — but it changes the cost shape. A subscription can auto-renew, can be harder to pause when you want a break, and can bundle in extras you did not price for.
Most of our board — 19 of 24 providers — sell pay-per-order with no tie-in, so you buy a box when you need one and stop when you want. The handful on a subscription or programme model are not worse, but they demand a different question: can you cancel easily, and what does it cost if you stop in month three?
The fix: know which model you are buying. For flexibility, choose a no-subscription, pay-per-order pharmacy. For structured coaching you will use, a programme may earn its fee — read the cancellation terms first.
Hidden cost 5: consultations, needles and add-ons
The consultation is usually free — most providers on our board charge nothing, and several only take payment if a prescriber actually prescribes. But the small print around the injection itself can carry cost. Some pharmacies include needles, wipes and a sharps bin; others expect you to source them. A pen needs needles every week, and a sharps bin is not optional. Anti-nausea medication is another quiet add-on: a minority bundle it in, most do not, and nausea is the most common early side effect.
The fix: check whether needles, a sharps bin and the consultation are included before you compare on price alone. "Free consult, needles included" is worth real money against a lower sticker price that omits them.
How to read a weight-loss injection price honestly
Put the five together and a checklist falls out. Before you buy, confirm:
- Ongoing price, not the promo — the discount lasts one month.
- Your likely maintenance dose price, not the starter — the ladder climbs.
- Delivery terms — free, threshold-gated, or a per-order fee up to £8.95.
- Model — pay-per-order or subscription, and how you cancel.
- What is included — consultation, needles, sharps bin, aftercare.
Do that and the "hidden" costs stop being hidden. They were always in the fine print; they only hide from a comparison that looks at one number. For where prices are heading, see our UK GLP-1 price trends for 2026; for a market snapshot, the GLP-1 price index for July 2026. None of this is medical advice — whether a weight-loss injection is right for you, and at what dose, is a decision for a qualified prescriber, not a price table.
FAQ
Why is my second month of Mounjaro more expensive than my first?
Almost certainly the promo cliff. Most providers discount the first order with a code, then charge the ongoing price from month two. On The Weight Clinic, a £125 promo starter becomes £160 ongoing at the same 2.5 mg dose, and more again as you step up to a maintenance dose. Always budget off the ongoing price, not the advertised first month.
Does the price of weight-loss injections go up as the dose increases?
Usually, yes. Both Mounjaro and Wegovy start low and step up over months, and price tends to climb with the dose. On The Weight Clinic, Mounjaro runs from £160 ongoing at the 2.5 mg starter to £295 at the 15 mg maximum. Price your likely maintenance dose, not just the starter, and check our cheapest by dose tracker for the best rate at each rung.
Do all providers charge for delivery?
No. On our board of 24 regulated pharmacies, 18 offer free delivery in some form; six charge, from £2.90 to £8.95 per order, sometimes only above a minimum spend. Because it is a monthly medicine, a small per-order fee adds up — a £5.95 charge is roughly £71 a year. Read the delivery line alongside the price.
Are subscriptions cheaper than buying each box separately?
Not automatically. Most providers (19 of 24 on our board) sell pay-per-order with no tie-in. A subscription or programme can be good value if you use the coaching and support it bundles, but it may auto-renew and can be harder to pause. If you want flexibility, choose a no-subscription pharmacy; if you buy a programme, read the cancellation terms first.
What extras should I check for beyond the headline price?
Whether the consultation is free (most are), and whether needles, a sharps bin and — if you want it — anti-nausea medication are included. Some pharmacies fold these in; others do not. "Free consult, needles included" can be worth more than a slightly lower sticker price that leaves them out.
Fewer hidden costs, seen before you start
The Weight Clinic is our pick for people who want the price they see to be close to the price they pay: a free consultation, monthly video reviews with a qualified prescriber, needles and next-day delivery included, and a refund if the prescriber declines to prescribe. The NEWME code takes £35 off your first order. Prescription-only medicine — suitability is your prescriber's decision, not ours.