Perimenopause constitutes the period immediately before menopause, and persists for 1 year after the final menstrual cycle.

The World Health Organization (WHO) defines perimenopause as the period preceding the menopause (when the biological and clinical features associated with the menopause commence) and the 1-year period after the final menses, which results from the loss of ovarian and follicular activity.1 It is an ill-defined period and constitutes the final years of the reproductive life of a woman.2

The period of perimenopause should not be confused with menopause.

When does perimenopause start?

Perimenopause begins with the onset of menstrual irregularity. It usually starts at 45 to 47 years of age and persists for 4 years or until menopause occurs. The timing of menopause may be affected by smoking, or underlying medical conditions. This transition is associated with multiple reproductive and hormonal changes that have an effect on a woman's overall quality of life.3

Symptoms of perimenopause

During perimenopause, women experience irregular menstrual periods, anovulatory cycles, shortened or prolonged menstrual cycles or longer periods of amenorrhea. These changes are associated with the reduced secretion of estrogen from the ovaries.2,3,4 The unpredictability of bleeding or spotting can be burden for many women.

Due to the changes in the hormonal profile, certain vasomotor symptoms such as hot flushes and night sweats are significantly evident during perimenopause. These symptoms are experienced by about 45% to 85% of women during the perimenopausal period.2,3,5

Hot flushes

Night sweats


Mood changes

Body fat changes

Low mood

The occurrence of hot flushes are attributed to change in the levels of estrogen, which has an effect on the thermoregulatory system in the hypothalamus.2,3

Perimenopause could be associated with an increased risk of low mood in women. The estrogen withdrawal theory suggests that the onset and worsening of mood symptoms during the perimenopausal period may be secondary to the reduced levels of estrogen.2,3

Sleep changes, insomnia and vaginal dryness are also commonly observed in perimenopausal women. Hormonal therapy is an effective treatment in providing relief of these estrogen-deficiency symptoms.2

  • References

    1. 1) WHO Scientific Group on Research on the Menopause in the 1990s (1994 : Geneva, Switzerland) & World Health Organization. (1996). Research on the menopause in the 1990s : report of a WHO scientific group. Geneva: World Health Organization. Available at Accessed on September 2021.
    2. 2) Santoro N. Perimenopause: from research to practice. J Womens Health (Larchmt). 2016 Apr;25(4):332-9.
    3. 3) Soares CD, Cohen IS. The perimenopause, depressive disorders, and hormonal variability. Sao Paulo Medical Journal. 2001 Mar;119(2):78-83.
    4. 4) Santoro N, Randolph JF. Reproductive hormones and the menopause transition. Obstet Gynecol Clin North Am. 2011 Sep;38(3):455-66.
    5. 5) Davis SR, Castelo-Branco C, Chedraui P et al. Understanding weight gain at menopause. Climacteric. 2012 Oct;15(5):419-29.


Femoston is a combination of 17β estradiol and dydrogesterone, which is indicated for postmenopausal women at least 6 months since last menses to provide relief from vasomotor symptoms.


Watch our menopause experts discuss the benefits of an individualised approach when it comes to HRT treatment.


Date of preparation: November 2021

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