Dydrogesterone is a molecule commercialized under the name Duphaston®. It is a drug in the class of progestogens. In other words, its action is similar to that of progesterone, a hormone produced by the ovaries. Duphaston® is thus primarily prescribed to compensate for a progesterone deficiency, notably for menopause that causes hormonal disruptions. It also has the effect of relieving pre-menstrual pains, can sometimes regulate genital bleeding or irregular cycles, and may heal some forms of sterility. The principal side effect is spotting, or bleeding outside of the normal menstruation period.