Menthol 30 insulin generally refers to Menthol 30 injection, the time when the drug works best needs to be differentiated and should be decided by the doctor according to the patient’s condition. Menthol 30 injection works faster than biphasic (premixed) human insulin, so it must generally be injected immediately before a meal. If necessary, it may be given immediately after a meal. Menthol 30 Injection contains 30% soluble menthol and 70% arginine menthol and can be used for the treatment of diabetes mellitus; it is contraindicated in the event of hypersensitivity to menthol or any other ingredient contained in this product or in the event of hypoglycemic episodes. It should be noted that adverse reactions such as hypoglycemia, edema, refractive errors and injection site reactions (pain, hives, inflammation, swelling and itching at the injection site) may occur after administration. Patients who need to use Mentholatum 30 Injection for treatment should use the drug under the guidance of a doctor, and if you are not sure when to use the drug, it is recommended to go to the hospital and consult a professional doctor to decide.