Cycle 17 added a backlog item we expected would produce a neat "site-selection" story: Cohens Chemist Manchester M1 3mi ring runs 13 branches at £127,582 per operating average — above Boots, above supermarket pharmacy, comfortably in profit. The obvious follow-up was: where would Cohens naturally extend next? Warrington, Bolton, Stockport, Rochdale — the Greater Manchester satellite towns were the candidates.

Cycle 19 pulled the 3-mile rings for all four. The answer is more interesting than "here are the greenfield gaps". Cohens is already there.

The Greater Manchester Cohens footprint (cycle 19)

Bolton runs more Cohens branches than Manchester itself. The Bolton BL1 1JR 3-mile ring contains 15 Cohens contractor codes (13 operating) — two more than Manchester M1. The operating average of £126,689 is within £900 of the Manchester average.

Stockport SK1 1AR runs 10 branches with a 100% operating rate. Stockport's operating average is the highest in the Cohens atlas at £131,356. The cycle 17 finding that M1 was the Cohens centre of gravity needs a revision: Cohens's commercial peak is Stockport, not Manchester.

Rochdale is the underperformer

Rochdale OL16 1JZ 3mi contains 4 Cohens branches: 3 operating, 1 ghost. The operating branches are FP201 (£131,605), FTA20 (£65,646), and FAJ06 (£51,367). The operating average of £82,872 is 35% below the rest of the Greater Manchester Cohens cluster.

Rochdale is the first Cohens catchment PharmSee has measured where the chain is visibly thin — half the operating branches are below £66k. This doesn't make Rochdale a closure candidate (all three are dispensing at healthy volumes), but it does mean the "Cohens M1 £127k economics" don't generalise across the GM perimeter. The cycle 18 backlog item framed Cohens as a "13-branch M1 £127,582 economics" model — Rochdale shows the floor of that model.

Warrington is the outpost

Warrington WA1 1QY 3mi contains exactly one Cohens branch: FQV12 at WA5 8UG, operating at £121,487. This is the cycle 19 discovery.

Cohens has 13 Manchester branches, 15 Bolton branches, 10 Stockport branches, 4 Rochdale branches — and then a single Warrington outpost. Warrington sits 18 miles from Manchester, on a direct rail line. The 3-mile catchment contains 42 pharmacies and 47 GP practices (1.12:1 GP-to-pharmacy ratio, the third-lowest pharmacy density among the four satellite towns). There is no structural reason Cohens shouldn't run 5–8 branches in Warrington.

This is the site-selection gap: Warrington is the single clearest Cohens extension opportunity in the M6 corridor. The existing WA5 8UG branch (FQV12) operates at £121,487 — identical to the Manchester/Bolton/Stockport cluster average, proving the economics work in Warrington.

The Bolton dominance

Bolton's 15 Cohens branches deserve a second look because the cycle 17 Manchester piece positioned Cohens as a Manchester chain:

The top Bolton branch (FL760, BL2 6NT) at £213,935 is higher than the top Manchester Cohens branch (FVY60, M11 4PA at £171,018). The top-2 Bolton branches sit above any Manchester Cohens branch. The "Cohens is a Manchester chain" narrative is wrong — Cohens is a Bolton chain with a Manchester branch cluster.

What this means for the cycle 18 sub-15h stacking arithmetic

Cycle 18's Boots sub-15h hour-stacking analysis concluded that the cycle 17 Manchester Cohens cluster was "the only urban geometry where the stacking arithmetic comes out positive". Cycle 19's finding that Bolton has 13 operating Cohens branches in a 3-mile ring — more than Manchester — suggests Bolton may produce a tighter hour-stacking geometry than Manchester. The Bolton Cohens branches cluster in BL1 and BL2 postcodes (mostly within 1.5 miles of each other), which is tighter than Manchester's spread across M6/M8/M9/M11/M12.

The stacking arithmetic that works in Manchester works in Bolton. It also works in Stockport — 10 branches, all operating, the tightest concentration geometry of all four sites.

Where Cohens would naturally extend

The site-selection answer is:

1. Warrington — single-branch outpost in a 42-pharmacy catchment. Room for 5+ more branches. The WA5 8UG economics already clear the bar.
2. Rochdale deepening — 4 branches, half at weak revenue, suggests operational absorption of underperforming single-site operators rather than greenfield extension. The chain is thin enough in Rochdale that an acquisition would measurably change the catchment economics.
3. Not Bolton or Stockport — the GM satellites are already at Cohens density parity with Manchester.

The "Cohens should expand into Warrington" recommendation is the cleanest follow-up from the cycle 17 M1 13-branch finding. It is a single-town, single-corridor, high-specificity site-selection case.

Explore the data

• Cohens chemist job search — current Cohens vacancies nationally
• Manchester M1 branch audit
• PharmSee location analyzer — run 3-mile audits for Warrington or your own corridor
• Greater Manchester pharmacy search

Methodology

Fresh cycle 19 pull via /api/location/analyze at each postcode, radiusMiles=3. Branch counts are NHS Digital contractor codes matching "COHENS CHEMIST" in the contractor name. Operating status uses the cycle 14 ghost convention (totalRevenue > 0). The Warrington sample is one-branch and statistically thin — the "Cohens extension" recommendation is a directional inference from the single data point, not a measured finding.