Hi! I am on the pump, but I use a Humalog insulin pen on some occasions. Since Humalog is a short-acting insulin, you would need a long-acting or base insulin as well. I really only use the pen if something happens to my pump or I wear a dress and can't physically wear my pump. The main difference between regular syringes and the pen is that the needle is not attached to the pen- you screw a disposable needle "cap" on every time you take insulin. The nice thing about the caps is that you can buy a very short needle and they don't hurt at all :) How much insulin you'd take would depend on what you BG was, if you were eating, exercising, etc. They are very convenient, but if you are mixing insulin, it may be easier to stick with regular syringes (unless there is a long-acting insulin pen available- I'm not sure of this).