Progesterone, Progestin

  • Physiology
  • Mechanism
  1. Progesterones are used in many contraceptives (e.g. Oral Contraceptives, mini pill, IUD, Depo Provera, Implanon)
    1. Progestins inhibit Ovulation
    2. Progestins thicken Cervical Mucus, preventing sperm from reaching the ovum
  2. Synthetic Progestins have Endometrial Activity, but also androgenic, Estrogenic and anti-Estrogenic Activity
    1. See Progestin Androgenic Activity
    2. See Progestin Endometrial Activity
    3. See Progestin Estrogenic Activity
  1. Overall Effect
    1. Lowers HDL-2 to Total Cholesterol ratio
  2. Factors related to unfavorable HDL effects
    1. Higher Progestational Activity
    2. Lower Estrogen to Progestin ratio
  3. Progestins most adversely effecting lipid (androgen)
    1. Levonorgestrel
  4. Progestins with most favorable lipid effects
    1. Progestin only formulations (mini pill)
    2. Desogestrel
    3. Norethindrone (low dose)