Some needles can be selected in the stomach, such as insulin, and some anticoagulants, such as doxycycline and namine. But generally speaking, the needle for spanking is intramuscular injection, and the needle for spanking is subcutaneous injection. Intramuscular injection is deeper than subcutaneous injection, so they can't replace each other. But if you really can't stand it, you can choose deltoid injection, which is located outside the upper arm and 2~3 fingers below the acromion.

By the way, it hurts to hit the stomach.