Abstract: A kit for subsequent injection and/or subsequent insertion of at least one medical substance in the fluid or liquid state and/or of at least one element in a human body injection or insertion site. The kit includes a first syringe element and at least one second syringe element. The first syringe element includes an internally hollow cylindrical body, a plunger and a first needle. The plunger is suitable to slide inside the cylindrical body in use. The at least one second syringe element includes a piston and a second needle. The at least one medical substance is inserted into the cylindrical body and the first syringe element is suitable to house, at least partially therein, the at least one second syringe element or the second needle is suitable to pass through the plunger in use.