There is proposed a method for using a preparation for lowering the cholesterol level of a patient. In preferred embodiments, the preparation essentially consists of an active substance being an aqueous solution of formaldehyde with a concentration of 36.5-40%, the active substance constitutes 2-6 weight units, and an additive being an isotonic solution of sodium chloride with a concentration of 0.85-0.95%, the additive constitutes from 998 to 994 weight units accordingly, to make the total of 1000 weight units. The method includes administering the preparation to the patient in the form of intramuscular injections with a predetermined dose at a predetermined time interval, thereby lowering the cholesterol level of the patient. It is preferable to choose the predetermined time interval from the group consisting of 7, 21, 30, and 60 days. It is also preferable to choose the predetermined dose in the amount of 5 mL.
