Perimenopause is a transitional phase before menopause, marking the end of a woman's reproductive years. We don't need to tell you: it can be a super confronting and confusing time.

Cycle durations start to change and you find yourself dealing with symptoms that you might have not experienced before asking the question “is this normal?”. 

At SheBANG! Woman, we want to empower women with the knowledge to understand what their bodies are going through. It can really help to know what’s happening and that it’s not going to last forever (and much less scary). 

During perimenopause there are significant hormonal changes occurring, leading to variations in menstrual cycle length and other symptoms. The hormones primarily involved in this process are estrogen and progesterone, two key reproductive hormones produced by the ovaries.

What Happens to Me When I Miss a Period in Perimenopause?

During perimenopause you may still experience symptoms similar to premenstrual syndrome (PMS) even if you miss a period. This is because your hormone levels, particularly estrogen and progesterone, fluctuate unpredictably during this time.

Estrogen levels may rise and fall erratically, leading to symptoms such as hot flushes, night sweats, mood swings, and changes in libido.

Progesterone levels may also fluctuate, which can contribute to symptoms like breast tenderness, bloating, and mood changes.

When you miss a period during perimenopause, it could be due to irregular ovulation or a decrease in the frequency of ovulation. As a result, your hormone levels may not follow the typical pattern of a menstrual cycle, leading to variations in symptoms.

It's important to note that perimenopause can vary greatly from person to person, so while some women may experience PMS-like symptoms even with missed periods, others may not.

What Are My Hormones Doing During Perimenopause?

  • Fluctuating Estrogen Levels: As you enter perimenopause, the ovaries gradually produce less estrogen. However, estrogen levels don't decline in a straight line; instead, they can vary greatly, leading to significant fluctuations. These fluctuations can cause changes in the menstrual cycle, making your periods longer, shorter, heavier, or lighter than usual. Sometimes, estrogen levels can spike, leading to particularly heavy or prolonged periods.

  • Decreasing Progesterone Production: Progesterone levels also decline during perimenopause. Progesterone is responsible for regulating the menstrual cycle and preparing the uterus for pregnancy. A decrease in progesterone can disrupt the normal cycle, leading to irregular periods. When ovulation does not occur, progesterone levels stay low, which can result in prolonged menstrual bleeding or skipped periods.

  • Irregular Ovulation: As perimenopause progresses, ovulation becomes more erratic. There may be cycles where ovulation does not occur at all (anovulatory cycles). Without the surge in progesterone that follows ovulation, the menstrual cycle can become unpredictable, contributing to the changes in period lengths.

  • Other Hormonal Changes: Besides estrogen and progesterone, levels of other hormones such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH) also change during perimenopause. FSH levels can rise as the ovaries become less responsive, a change that is sometimes used to diagnose the transition into menopause. These hormonal changes can further contribute to irregular menstrual cycles.

What Happens when Your Ovaries Don’t Release Eggs (Anovulation) in Perimenopause?

Anovulation refers to a cycle during which the ovaries do not release an oocyte, or egg, which means ovulation does not occur. This can be a common occurrence in perimenopause, characterised by significant hormonal changes and increasingly irregular menstrual cycles.

During perimenopause, the body's levels of estrogen and progesterone, the hormones that regulate the menstrual cycle, become erratic due to the decreasing ovarian reserve (the remaining number of eggs). Here's what happens during an anovulatory cycle in the perimenopause years:

  • Hormonal Fluctuations: The normal hormonal patterns required for ovulation become disrupted. Typically, a surge in luteinizing hormone (LH) triggers ovulation, but during perimenopause, hormonal fluctuations may prevent this surge from occurring effectively.

  • Follicular Development: In a regular menstrual cycle, follicles in the ovaries mature and one becomes dominant, eventually releasing an egg during ovulation. In anovulatory cycles, these follicles may not develop properly or the dominant follicle may not release an egg, despite some level of menstrual cycle activity continuing.

  • Menstrual Cycle Impact: Anovulation can lead to a variety of menstrual irregularities during perimenopause, including missed periods, irregular periods, or lighter or heavier bleeding than usual. Since ovulation is a key event that triggers the second half of the menstrual cycle, its absence can disrupt the predictable pattern of menstrual bleeding.

  • Progesterone Production: After ovulation, the corpus luteum (the remains of the follicle that released the egg) produces progesterone, which helps prepare the uterine lining for a potential pregnancy. In an anovulatory cycle, this progesterone boost doesn't occur, which can affect the menstrual cycle and lead to symptoms like irregular bleeding.

It's worth noting that anovulation is not uncommon and can occur in women of any age for various reasons, but it becomes more frequent during perimenopause due to the natural decline in reproductive hormones. Changes in period length and menstrual flow are also common during perimenopause, extremely heavy bleeding, very frequent periods, or periods that last longer than a week should be discussed with your healthcare provider along with persistent anovulation or other symptoms troubling you.

The Four Stages of Perimenopause

  1. Very Early Perimenopause
  2. Early Menopause Transition
  3. Late Menopause Transition
  4. Late Perimenopause.

This diagram shows the absolute hormonal rollercoaster we're on (that we did NOT ask to get aboard!) *note estradiol is a type of oestrogen.

In the diagram above it shows you what oestrogen and progesterone are up to (dizzying, we know!) and see below for a list of perimenopause symptoms they cause.

Symptoms of High and Fluctuating Estrogen

  • Hot flashes and night sweats (2 cups a day of this will help reduce these)
  • Heavy and painful periods
  • Breast pain
  • Irritable mood
  • Depression
  • Insomnia (take this twice a day to help)
  • Migraines.

Symptoms of Low Progesterone

  • Mood changes - less able to cope with stress, increased risk of depression, anxiety and memory loss
  • Sleep disturbances 
  • Hot flashes and night sweats 
  • Heart palpitations
  • Migraines
  • Heavy periods
  • Painful periods.

Note that some of the symptoms are the same for low progesterone and fluctuating and high oestrogen as they are caused by the combination of the low progesterone and high and fluctuating oestrogen.

Need help with sleep, hot flushes, night sweats and migraines?  Try our Peri Chai Latte, Peri Hot Choccy or Peri Peppy Shroom Latte (take 2 cups a day for maximum results)

Read about the different stages below and what symptoms to expect and what your period might be doing in the four difference stages.

STAGE 1: Very Early Perimenopause (lasts 2 - 5 years on average)

  • Cycles are still regular but could be shorter in length, maybe between 21-26 days. 
  • Likely to have less progesterone and more oestrogen.
  • Symptoms might be heavier periods, increased period pain, migraines, sleep disturbances.

STAGE 2: Early Menopause Transition (2 - 3 years on average)

  • Cycles are starting to be irregular and vary in length up to seven days
  • Likely to have less progesterone and more oestrogen. Oestrogen is starting to fluctuate and when it drops it goes lower than you are used to.
  • Symptoms might be more hot flashes and night sweats.

STAGE 3: Late Menopause Transition (you might be 4 years away from menopause)

  • You start to miss cycles or have your first cycle that is longer than 60 days.
  • Symptoms could increase: hot flashes/night sweats and heavier periods. Breast pain should ease if you have any.

STAGE 4: Late Perimenopause (the twelve months from your final period)

This is the start of your body getting used to low oestrogen and you should start to feel less of the symptoms associated with the wild fluctuating oestrogen levels like migraines and mood symptoms. 

While you are transitioning from late menopause transition to late perimenopause you will float between the two stages until you don’t have a period for 12 months (at that point you have reached Menopause).

For example you might not have a period for 8 months and feel less of the wild fluctuating oestrogen symptoms. Then you might get another period and experience symptoms and then the countdown starts again until you reach 12 months with no period.  Drives you nuts!

Wrap up

We hope that helps unravel some of the mystery around the duration of cycles and what’s happening in that beautiful body of yours. Please know that there are lifestyle choices and natural supports that can help you deal with the perimenopause symptoms that you might be dealing with. You can dive in here and read more on How to balance your hormones naturally in Perimenopause.


March 13, 2024 — Angela Greely

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