Allylestrenol is primarily used in medical settings to support pregnancy, particularly in cases where there is a risk of miscarriage or premature labor. It helps by maintaining the uterine lining and reducing contractions, thereby promoting a stable environment for fetal development. Additionally, it is sometimes prescribed to treat hormonal imbalances in women, such as irregular menstrual cycles or conditions related to progesterone deficiency. Its ability to mimic the effects of natural progesterone makes it a valuable therapeutic agent in gynecology and obstetrics.