In a statement released Tuesday, Pfizer Canada said the drug market chain "quickly" informed the company, notifying them on April 2, and "took immediate corrective measures."
On Monday, officials with Shoppers urged women in Alberta to check the expiry date on their Alesse, saying it had dispensed expired pills to about 100 women in Western Canada between March 16 and April 1.
Shoppers also said had contacted everyone who was given expired product in British Columbia, Saskatchewan and Manitoba and offered to replace the product and provide information and counselling.
The drug market chain blamed human error at its distribution centre in Calgary for shipping the expired pills to stores.
Vincent Lamoureux, director of corporate affairs for Pfizer, said in the release that the company does not recommend using expired products.
Shoppers Drug Mart has launched a review of its internal protocols to determine how to prevent such errors in the future.