Idiot_Savant posted...
Oh thanks I still haven't used all mine up from last time but I'm sure they're expired by now
Depends how old they are and what brands you're looking at. Most of the early ones shipped with a shelf life of a year, but some brands got that extended by an extra year beyond their printed dates (at least, Health Canada approved that extension. I'm not entirely sure what the FDA has done). If they're more than two years old, they're probably dead regardless, but if they're newer than that they might be okay.