Parents, are you having trouble finding an EpiPen at your local pharmacy? Pfizer Canada says that “increased demand” is to blame but that stores should be resupplied with inventory by next week.

They’re injected as emergency medicine for severe allergies to food and bug bites, but in the past few months, the price of the EpiPen has soared to more than $600 in the U.S. for two syringes.

Here's why U.S. parents are dealing with sky-high price hikes for EpiPen.