Abstract: The present invention relates to a novel local contraceptive method according to which the passage of spermatozoa in the cervical canal is prevented, the said method being characterized in that the physico-chemical structure of the cervical mucus is modified by means of at least one coagulating agent. It also concerns compositions for putting this novel method into effect, particularly compositions comprising at least one coagulating agent such as tannic acid. These compositions may also contain an agent which assists and completes the action of the coagulating agent.