Shipping a class 3 drug through the USPS is an additional charge if caught. Myself personally I would just carry it through TSA and check the pins. A 10 ml bottle will not trigger the 100 ml limit. TSA is not the DEA, FBI, CIA, or any other national police force. They are transportation security authority. That means they are responsible for making sure nothing is taken on to a plane that poses an immediate danger. You could tell most that you have a testosterone replacement script or whatever script you want to tell them and they would believe you, or have no choice but to believe you if they even question it. Most likely they will look at the X-ray and believe it is insulin. Unless you give them some other reason to check your bag they won't.