Muscle pain after injection, the main reason is caused by the stimulation of drugs, some drugs can lead to local vascular constriction, resulting in pain, but also may lead to local nerve damage, causing pain. For example, when injecting penicillin, the patient’s hip pain is very obvious, before injecting penicillin, let the patient relax, don’t be nervous, and then injecting drugs in the process, to keep the muscle relaxation, to be able to stretch the drug in the muscle completely, and soon after the absorption of the drug, the pain will be significantly reduced. In the injection of progesterone, in order to preserve the fetus will be injected with hormones, progesterone is a fat-soluble drug, the composition of the oil is relatively high, in the injection, the local pain is also more obvious, there may be the formation of hard knots. To eliminate the pain, you can use hot towels in the local area, accelerate the blood circulation inside the muscle, which is conducive to the absorption of the drug.