The Canadian distributor of the EpiPen says there is a shortage of one size of the emergency treatment for people at risk of life-threatening allergic reactions.
Pfizer Canada says there is a shortage of the 0.3-milligram form of the EpiPen because of a manufacturing disruption.
The 0.15-mg EpiPen Jr product for young children is not affected.
The company anticipates the shortfall in supply will be resolved by March 2.
It says additional limited inventory will be available at the beginning of February, but will be carefully managed.
EpiPens expire on the last day of the month indicated on the product packaging.
But Health Canada advises anyone having an anaphylactic reaction to use their expired product and immediately call 911.
Pfizer is asking pharmacists to keep the supply interruption in mind when filling prescriptions, as there are currently no alternative auto-injectors available on the Canadian market.