It is very easy to use there is a great web site that has pictures etc on how to use and give an injection. I printed it out and keep w/ the injectable. There is sterile/ water on top of the powder, so you pop the top and mix the water and powder. I will look up the site w/ the clear instructions. I did have one go bad and kind of mix up on its own so you need to check them once a year, I think they are only good for a year?