Cost per percentage point: Mounjaro vs Wegovy value analysis
Headline price is the wrong number. When people ask about Mounjaro vs Wegovy cost, they usually compare monthly invoices side by side and stop there. But the two drugs do not deliver the same result, so a like-for-like price tells you almost nothing about value. This report divides real UK prices by trial-average weight loss to get a cleaner metric: cost per percentage point of body weight lost.
Every price below is pulled from our live price board of 24 regulated UK pharmacies, checked on 4 July 2026. The weight-loss percentages come from the drugs' pivotal trials. We show our working so you can sanity-check it.
How the cost-per-percent metric works
The maths is deliberately simple. Take the ongoing monthly price at a drug's top maintenance dose, then divide by the average total-body-weight reduction that dose produced in its main trial:
Cost per percentage point = monthly price ÷ trial-average % weight lost.
The percentages we use are the well-established headline figures. Tirzepatide (Mounjaro) averaged about 21% total-body-weight loss at its highest dose in SURMOUNT-1. Semaglutide 2.4 mg (Wegovy) averaged about 15% in STEP 1. These are trial means over roughly 68–72 weeks; your own result could be higher or lower, and side effects or dose ceilings may stop you reaching the top dose at all.
A lower cost-per-percent number is "better value" only in the narrow sense of pounds spent per unit of average loss. It says nothing about which drug is right for a given person — that is a prescriber's call, informed by your health history, not a spreadsheet's.
Mounjaro vs Wegovy: the value table
Figures below use the median ongoing price across all 24 providers on our board, plus the current cheapest, for each drug's top maintenance dose. Promo codes are excluded — they only touch month one, and value is a long game.
| Drug & dose | Median price / 4 wks | Cheapest / 4 wks | Trial-avg loss | Cost per % pt (median) |
|---|---|---|---|---|
| Mounjaro 15 mgtirzepatide · top dose | £318.00 | £288.99 | ~21% | £15.14 |
| Wegovy 2.4 mgsemaglutide · top dose | £199.99 | £174.99 | ~15% | £13.33 |
Median and cheapest are computed from ongoing (non-promo) prices across 24 providers on the GLP Prices board, 4 July 2026. Trial averages: SURMOUNT-1 (tirzepatide 15 mg) and STEP 1 (semaglutide 2.4 mg). Individual results vary.
Read at the median, Wegovy is the value winner: £13.33 per percentage point against Mounjaro's £15.14. That is about a 12% premium to buy into tirzepatide's larger average loss.
But look at the totals, not the ratio. At those trial averages, a full Mounjaro course targets roughly six more percentage points of body weight than Wegovy — for many people that is the entire point. You are paying more per unit and buying more units. Whether the extra loss justifies the higher monthly outlay depends on your goal, and your prescriber's view of whether the top dose is suitable.
The Weight Clinic — monthly video reviews, refund if declined
The Weight Clinic is our pick for people starting either drug: a qualified prescriber reviews you by video each month, and if they decline to prescribe you get a refund. Their Mounjaro 15 mg is £295 and Wegovy 2.4 mg is £230 ongoing — and the NEWME code takes £35 off your first order.
Why the cheapest per-percent isn't always the cheapest headline
Wegovy wins on value partly because it is simply cheaper in absolute terms. Its top dose has a median of £199.99 across our board, versus £318.00 for Mounjaro's top dose — a wide gap driven by list pricing and supply, not by any provider's generosity. If your only constraint is monthly budget, Wegovy is the lighter commitment before you even reach the value maths.
The dose ladder matters too. Neither drug jumps straight to its top dose. Both start low — Mounjaro at a 2.5 mg starter, Wegovy at 0.25 mg — and climb over months. In those early weeks you pay a maintenance-style monthly fee while still building toward the dose that delivers the trial-average loss, so real-world cost per percent in month one or two is worse than the steady-state figures above. We track the full ladder in our cheapest GLP-1 by dose tracker.
Watch the costs the value metric hides
Cost per percentage point captures the drug price and the average outcome. It does not capture the frictions around them, and those can quietly rewrite your true spend:
- Delivery. Some providers bundle free cold-chain delivery; others charge per order. Over a year of monthly deliveries that difference compounds.
- Consultation and review fees. A "free consultation" that becomes a paid monthly review changes your effective cost per percent more than a £5 price gap on the pen.
- Dose changes and re-titration. If side effects force a dose drop, your loss trajectory and your cost-per-percent both move.
- Stopping and rebound. These are maintenance medicines. Value calculated over a few months looks very different from value over a year.
We break these down in the hidden costs of weight-loss injections. For where prices sit this month across every dose, see our July 2026 GLP-1 price index, and for the direction of travel, our 2026 UK GLP-1 price trends.
So which is better value?
On the numbers alone, Wegovy 2.4 mg is the cheaper drug per percentage point of average loss — roughly £13 versus £15 at the median. But "better value" and "better result" are not the same question. Mounjaro's higher price buys a larger average total loss, and for some people that extra weight off is worth the premium many times over.
Use cost per percent to understand the trade-off, not to make the decision. The decision belongs to a prescriber who knows your health, your BMI, your history and your goals. Both are prescription-only medicines under NICE and MHRA guidance, and neither is suitable for everyone.
Get a prescriber's view — refund if you're declined
Whichever way the value maths points you, a qualified prescriber decides what's appropriate. The Weight Clinic, our recommended provider, offers monthly video reviews and refunds your payment if they decline to prescribe. New patients save £35 with code NEWME.
FAQ
Which is cheaper per percentage point, Mounjaro or Wegovy?
On the maintenance doses used in the pivotal trials, Wegovy 2.4 mg tends to work out slightly cheaper per percentage point of body weight lost, because although its median UK price is lower than top-dose Mounjaro, its average trial weight loss is also lower. The gap is narrow and flips depending on which provider and dose you pick.
Does cheaper per percent mean I should choose Wegovy?
No. Cost per percent is one lens, not a prescription. Mounjaro produced more total weight loss in trials, so if your goal is maximum loss the higher monthly cost may still be worth it. The prescriber decides what is appropriate for you.
Where do the percentage figures come from?
From the published pivotal trials: SURMOUNT-1 for tirzepatide (Mounjaro) and STEP 1 for semaglutide (Wegovy). Individual results vary widely and no provider can promise a trial-average outcome.
Do the first-month promo prices change the value maths?
Yes, for month one only. A promo code lowers your entry cost but not the ongoing price you pay at the maintenance dose, which is what drives long-term cost per percent.
Is the £35-off NEWME code applied to the value figures?
The value table uses ongoing maintenance prices, so it excludes promos. The NEWME code lowers The Weight Clinic first-month starter price only; the value comparison reflects the steady-state cost you actually live with.
Reviewed July 2026. Price figures from the GLP Prices board, checked 4 July 2026. This is price information and general context, not medical advice.