Comparable-store sales at Walgreens rose sharply in July, as the return of Express Scripts drug plan members continued to fuel the drug chain's improving pharmacy results.

The drug chain reported a 6.3% comp-store sales gain, marking its largest monthly same-store sales increase this year. A rise in front-end business complemented strong gains in comparable pharmacy sales and script count.

DEERFIELD, Ill. — Comparable-store sales at Walgreen Co. rose sharply in July, as the return of Express Scripts drug plan members continued to fuel the drug chain’s improving pharmacy results.

Walgreens said Monday that comp-store sales advanced 6.3% for July, reflecting a positive impact of 1.4 percentage points from calendar day shifts (one extra Wednesday and one fewer Sunday) and a negative impact of 1.8 percentage points from introductions of lower-priced generic drugs.

The July result marked Walgreens’ largest monthly same-store sales gain this year and was up from recent increases of 2.3% in June and 2.8% in May.

In the front end, same-store sales rose 2.3% for July. Walgreens said customer traffic in comparable stores dipped 1.2%, yet basket size grew 3.5%.

July comparable pharmacy sales climbed 8.8% and increased by a calendar day-shift adjusted 6.6%, according to Walgreens. The company said calendar day shifts positively impacted pharmacy same-store sales by 2.2 percentage points. Meanwhile, new generics negative impacted calendar day-shift adjusted comparable pharmacy sales by 2.8 percentage points.

Walgreens noted that the percentage of Express Scripts prescriptions returning to its pharmacies continued to rise in July.

Prescription count at comparable stores increased 9.5% for the month and was up 7.3% on a calendar day-shift adjusted basis. The drug chain said calendar shifts positively impacted prescriptions filled at comparable stores by 2.2 percentage points.

Walgreens’ July same-store sales performance was slightly better than expected, according to analyst Mark Miller of William Blair & Co.

"Walgreens’ July total comp-store sales increase of 6.3% exceeded the consensus mean of 5.9%. Front-end comp growth of 2.3% was slightly above the 2.1% consensus, and reported pharmacy comps of 8.8% topped the 8.3% consensus projection," Miller wrote in a research note released Monday.

"Calendar-adjusted script growth of 7.2% was essentially in line with results of the past few months, although the two-year stacked number improved 210 basis points from June. Script growth continues to be predominantly driven by the return of Express Scripts customers and incremental Medicare Part D share gains," he added.

Overall in July, Walgreens’ revenue rose 8% to $6.03 billion from $5.59 billion a year earlier, reflecting gains of 3.6% in the front end and 9.9% in the pharmacy. Walgreens said pharmacy sales represented 64.6% of total sales for the month.

Registrations for the Balance Rewards customer loyalty program totaled 79 million through July, compared with over 75 million through June. 

Walgreens reported that calendar year-to-date sales came in at $42.02 billion, up 3.4% from $40.64 billion in the prior-year period. Fiscal 2013 year-to-date sales, covering 11 months, were $66.05 billion, up 0.4% from $65.79 billion a year earlier.

Walgreens opened nine stores in July, including one relocation, and closed one store. As of July 31, the retailer operated 8,105 drug stores, 184 more than a year ago, including 67 net stores acquired over the last 12 months.