The two sides reported no headway from a three-hour bargaining session Thursday.
The union representing 1,200 pharmacists at 400 stores in northern Illinois and northwest Indiana began a strike Wednesday night.
All of the Walgreens pharmacies remain open but most have shortened hours.
Union leaders say Walgreen pharmacists are overworked because of staffing shortages. They're demanding better work schedules but say Walgreen's salary offer is fair.
The company insists the union is after more money despite what it says publicly.
Walgreen says more than 200 pharmacists have crossed picket lines to report to work. The union says fewer than 100 have broken ranks.