Let's be honest: micro-needling is scary, especially a DIY method. Do not be afraid of DIY methods. The cartridges are for one-time use. Sterilization is essential, but this fact alone makes this system extremely safe. There is no need to spend $50-500 or more to have someone else do this for you. Follow the instructions on us.drpen.co for the cartridge needle counts for your condition and the recommended depth levels for different sections of your face and body. Many believe there are different cartridges for different depths, but this pen is adjustable from 0mm to 2.5mm for every cartridge type. You can get the depth you need from any needle cartridge for your exact condition. Also, all Dr. Pen sellers on Amazon are the same; do not fear so many vendors selling the same pen. They are all the same thing; ensure they have the QR validation code and scratch-off code on the side of the box when it arrives. I first used a 5% lidocaine cream before needling, but at a high RPM setting, it is unnecessary from a pain perspective. Enjoy this fantastic tool and say goodbye to your previously expensive sessions. This is the ultimate device for DIY face damage repair.