The UK margin table, at list price
After Lilly's September 2025 UK list-price rise, 2.5mg from £92 to £133, 15mg from £122 to £330, several doses are loss-making at market retail. Against Medino's tracked market-average retail prices in August 2026:
- 2.5mg: £169.16 retail against £133 cost, +£36, 21%
- 5mg: £198.68 against £180, +£19, 9%
- 7.5mg: £253.42 against £255, −£2
- 10mg: £285.26 against £255, +£30, 11%
- 12.5mg: £302.01 against £330, −£28
- 15mg: £319.14 against £330, −£11
One rebate data point is public: Lilly supplying 15mg at £247.50 rather than £330, a roughly 25% discount. Extrapolating that ratio across doses gives margins of 18–41%. That extrapolation is an estimate from a single confirmed point, but the conclusion that survives either way is that without a manufacturer arrangement you cannot price competitively at the doses patients titrate to.
One patient over twelve months
Three scenarios, using market-average retail and the rebated cost estimate, with an illustrative £150 CAC:
- Best: full titration, stays twelve months: £3,442 revenue, £2,597 COGS, £845 gross margin (24.6%), +£695 after CAC.
- Base: plateaus at 10mg, churns at month six: £1,477 revenue, £1,000 COGS, £477 margin (32.3%), +£327.
- Worst: side-effect drop-off at month three: £621 revenue, £426 COGS, £195 margin, +£45: barely covering acquisition.
- Tail risk: two months at a £250 paid-social CAC: −£117.
Two things fall out. Churn timing, not churn rate, is the risk: the same patient leaving at month two is a loss and at month six is fine. And blended margin percentage improves when patients churn early, because the high doses are the thin ones. A healthy-looking margin line can be hiding a broken business.
Retention, from the best available data
Prime Therapeutics' claims book: one-year persistence rose from 33% (2021 cohort) to 62.6% (2024 cohort) as shortages resolved. Two-year is about 15%. Three-year is 8.1%: one in twelve.
Of those who stop, side effects account for about 28% and cost for about 13%. A 170% list-price rise lands directly on that second number.
CAC, the number that does not exist
No UK or German customer acquisition cost for this category is published anywhere. Every payback figure above rests on an assumption. The best available proxies are US:
- Hims & Hers spent 39% of revenue on marketing in FY2025, improving to 34% by Q2 2026. Gross margin fell 79% → 74% → 64% as it shifted from compounded to branded GLP-1 supply. That last number is the most important read-across in this atlas: branded-only markets structurally cap gross margin far below what the US compounded era enjoyed, and every European market is branded-only.
- LifeMD spends about $28m a quarter on marketing and said its CAC ran "approximately 50% lower than peak" in mid-2026. It cut its intro offer from $79 to $39 in June 2026, which moved multi-month plan adoption from 25% to 85% of signups. It also stated plainly that it receives no economics from either Novo or Lilly.
What it costs to compete
Voy has raised roughly £59m+ across four rounds. Numan raised $60m in July 2025 on over $90m of 2024 revenue. Juniper's parent Eucalyptus raised at least $148m before being acquired for up to $1.15bn. Oviva raised €200m in January 2026.
That is the realistic floor for building a competitive brand, clinical-ops and pharmacy stack in this category. It is not a bootstrap opportunity on the consumer side.
The one genuinely encouraging number
The NHS rollout is not eating the UK private market. Against a three-year target of 220,000 patients, year one delivered 14,417 across 28 reporting ICBs, a fifteen-fold shortfall, while private out-of-pocket patients exceed 2 million, roughly seven to one versus NHS-funded. Private weight-management medicine spend runs about £210m a year, 80% of it through online providers, and 3.3 million UK adults say they intend to start within twelve months.
Demand is not the problem. Access to margin and access to an audience are the problems.