 Due to its progestogenic activity, dydrogesterone can produce antigonadotropic effects at sufficient doses in animals.However, it does not suppress secretion of the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), or inhibit ovulation at typical clinical dosages in humans.Oral doses of dydrogesterone of 5 to 40 mg/day on days 5 to 25 of the cycle fail to suppress ovulation (assessed by urinary pregnanediol and laparotomy), and one study found that ovulation persisted even in women treated with an oral dosage of as great as 400 mg/day (assessed by visual inspection of the ovaries).