vape cartridges contain a mouthpiece, chamber and heating element, which is activated upon initiated contact with a vape battery. The chamber of a vape cartridge is filled with oil or distillate, which contains concentrated amounts of cannabis cannabinoids and terpenes. How long does the oil in a cartridge last? In W Vapes 500mg cartridges are around 4 to 5 grams of cannabis. It really depends on how much you use. Cannabinoids can degrade over time although there is not really a shelf life to the oils.