I am not sure how common these are but they have made my life SO much easier after being on TRT. The pharmacy I get my Test from has started selling these "vial adapters". Basically its an adapter that you penetrate the rubber of the vial one time with. The syringe then screws onto the top and you can with draw the formula without having to use a large gauge needle and switch to the injection needle. This allows the rubber of vial to be penetrated only one time, limiting the amount of "germ introduction".