Insulin for type 1 diabetes can be injected before bedtime if it is a long-acting insulin, and before meals if it is a short-acting insulin, and you should consult your doctor for specific methods. Insulin that can be injected after dinner is usually long-acting insulin, such as insulin glargine and dextran. Most people choose to inject before going to bed because injecting at this time can effectively control fasting blood glucose in the next morning and maintain stable blood glucose throughout the day the next day. Moreover, the risk of hypoglycemia is relatively small after injection of long-acting insulin. In the case of short-acting insulin, due to the faster onset of action of the drug, injection before meals can prevent blood glucose spikes after meals. It is recommended that patients with type 1 diabetes follow the doctor’s instructions to inject insulin on time, and consult a doctor if hypoglycemia and other discomforts occur.