A refrigerant additive supply device can include an outer rigid container, an inner flexible bag positioned in the outer rigid container and defining a space therebetween where the inner flexible bag contains an additive without a refrigerant, a valve in fluid communication with the inner flexible bag, an actuator operably coupled to the valve, and a propellant sealed within the space, where the inner flexible bag has a device pressure that allows flow of the additive into a refrigerant circuit when the actuator is depressed. Other embodiments are disclosed.