Ultra-low-dose estradiol and norethisterone acetate: effective menopausal symptom relief

Climacteric. 2007 Apr;10(2):120-31. doi: 10.1080/13697130701298107.


Objective: To evaluate the efficacy of two ultra-low-dose 17beta-estradiol plus norethisterone acetate (NETA) treatment regimens for relieving menopausal symptoms.

Design: A total of 577 postmenopausal women were enrolled, in three treatment groups in a double-blind, randomized, placebo-controlled study of 0.5 mg 17beta-estradiol + 0.1 mg NETA or 0.5 mg 17beta-estradiol + 0.25 mg NETA or placebo. Participants returned at weeks 4, 8, 12 and 24 for climacteric complaint evaluation based on a daily diary vasomotor symptom record. Patients were assessed by the Greene Climacteric Scale and urogenital symptoms were also evaluated.

Results: Treatment with ultra-low-dose 0.5 mg 17beta-estradiol + 0.1 mg NETA (0.1 Group) or 0.5 mg 17beta-estradiol + 0.25 mg NETA (0.25 Group) effectively reduced the severity and number of hot flushes within the initial weeks of therapy. Compared to placebo, a rapid, statistically significant decrease in the frequency and severity of hot flushes was achieved by week 3, followed by further improvement which continued throughout the study. There were no statistically significant differences between the active treatment arms.

Conclusions: The data show that both ultra-low-dose regimens are effective in reducing the severity and number of hot flushes compared to placebo, with good safety profiles.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Contraceptives, Oral, Synthetic / administration & dosage*
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Estradiol / administration & dosage*
  • Estrogen Replacement Therapy*
  • Factor VII / analysis
  • Female
  • Fibrinogen / analysis
  • Hot Flashes / drug therapy*
  • Humans
  • Hydrogen-Ion Concentration / drug effects
  • Menopause
  • Middle Aged
  • Norethindrone / administration & dosage
  • Norethindrone / analogs & derivatives*
  • Norethindrone Acetate
  • Severity of Illness Index
  • Vagina / chemistry


  • Contraceptives, Oral, Synthetic
  • Estradiol
  • Factor VII
  • Fibrinogen
  • Norethindrone Acetate
  • Norethindrone