A spanking injection is what is medically known as an intramuscular injection. It is usually painful, but the pain level is usually tolerable for adults. Generally, there will be pain during a spanking injection, but the pain is tolerable for most adults. It should be noted that the pain level of spanking injection is related to the injection manipulation, injection manipulation strength, drugs and other factors. If the drug is less irritating, pushes the drug slowly and has a good grasp of the strength, the pain will not be very obvious. In addition, everyone feels pain differently, and those who are sensitive to pain may feel obvious pain from the spanking injection. It is worth reminding that you should avoid strenuous activities when having a spanking injection, otherwise it is not conducive to the injection operation. If you feel unwell, you should seek medical treatment and do not blindly perform intramuscular injection on your own.