Chorionic gonadotropin refers to chorionic gonadotropin. Painful buttocks with hard lumps after chorionic gonadotropin injection are usually related to factors such as too high drug consistency, too fast injection speed and local infection. 1. Drug concentration is too high: if the concentration of the drug is relatively high, there may be pain in the buttocks within a short period of time after injection and there will be hard lumps. 2. Injecting too fast: If the chorionic gonadotropin is pushed too fast, it may affect the absorption of the drug, leading to the formation of subcutaneous bruises, and at this time, hard lumps will be formed locally and there is a sense of pain. 3. Local infection: after injecting chorionic gonadotropin, if you do not pay attention to local cleaning and care, it is easy to get infected with bacteria, when the bacteria repeatedly stimulate the local skin will cause surface pain, and there will be hard lumps. After chorionic gonadotropin injection buttock pain with hard lumps, do not sit all the time within a short period of time, so as not to press the needle hole resulting in pain aggravation; the appearance of physical discomfort timely medical treatment, to avoid the development of the disease. Drugs should be applied under the guidance of a doctor.