What is perimenopause?

Perimenopause marks the transition of the female body into menopause. During this phase, the amount of female hormones, especially estrogen, decreases, resulting in the first irregular menstrual cycles. At the beginning of perimenopause, the phase of follicle maturation shortens, resulting in a generally shorter cycle. In later perimenopause, just before menopause proper, irregular cycles become more frequent, often without ovulation, and menstrual irregularities may occur. The duration of perimenopause varies greatly from woman to woman. While some women experience this transitional phase for only a few months, for others it can last up to eight years. On average, however, the time span is four to five years.

During perimenopause, many women experience a change of consciousness of sorts. Instead of focusing on their fertile days they now turn their attention to the end of their fertile lifespan. While Daysy cannot predict exactly how your body will handle this sensitive transition, Daysy can help you recognize, understand and deal with the current changes.

Premenopause, Perimenopause, Postmenopause

What is the difference with menopause?

Menopause (The time of the last menstrual bleeding) marks a period in a woman's life when her fertility declines and the last menstrual period triggered by ovulation occurs. This stage usually occurs between the ages of 45 and 55, although experiences can vary greatly from woman to woman. The transition into menopause is called perimenopause, is a gradual process in which the different phases often merge seamlessly.

Cycles during perimenopause: insight into hormonal change

As we age, the ovaries respond less and less to hormonal stimulation. This is because the number of follicles drops to about 1000 during menopause (for comparison, at the end of puberty, a woman has about 250,000 germ cells per ovary that can mature into follicles). As the ovaries become less sensitive to regulatory hormones, the release of follicle-stimulating hormone (FSH) is increased. This results in a strong stimulation of follicular maturation and thus estrogen production during this time. The consequence of this dominance of estrogen is always a (relative) deficiency of progesterone. This hormonal imbalance is mainly responsible for the typical symptoms of perimenopause.

Ovulatory and anovulatory cycles

With decreasing estrogen levels and increasing FSH levels to stimulate follicular growth, two things can happen during perimenopause:

1. Ovulatory cycle

Follicles respond, estrogen levels rise, and LH (luteinizing hormone) triggers ovulation (ovulatory cycle). An early sign of perimenopause is often a shortening of the menstrual cycle by about 2-4 days1. This is due to a rapid ovarian response to increased FSH levels during perimenopause, resulting in premature ovulation and thus a shorter cycle. In addition, the gradual decline in progesterone levels during this time can lead to heavier menstrual bleeding, regardless of estrogen levels. This is "true menstruation" accompanied by a rise in temperature from 10-16 days prior. Shortening of cycles by a few days are the first typical recognizable changes that occur in perimenopause.

Premenopause, Perimenopause, Postmenopause

(It's important to know that menstrual cycles can get shorter for a variety of reasons. So you shouldn't immediately assume you're reaching perimenopause just because your cycle is a little shorter in your 30s. In fact, the average cycle length decreases with age, from about 29 days for people in their 20s to about 26 days for people in their 40s).

By tracking your menstrual cycle in your forties with Daysy tracks, you can develop a better understanding of your regular cycles in perimenopause. You'll also be able to quickly see if your cycle has changed over time in your stats in the DaysyDay app. Daysy has been programmed to accurately distinguish non-fertile days from fertile days, even with variable cycles.

2. Anovulatory cycle

The follicles do not respond, the estrogen level remains low as a result, and ovulation does not occur (anovulatory cycle). In contrast to a cycle with ovulation, due to the lack of reaction of the ovaries in an anovulatory cycle, there is no temperature increase in the luteal phase and the cycle ends with a usually somewhat shorter breakthrough bleeding.

The bleeding that occurs after an anovulatory cycle is, strictly speaking, not a "real" menstruation, but an estrogen breakthrough bleeding. It is caused by low progesterone levels and the accumulation of uterine lining. You can recognize an anovulatory cycle in your Daysy by the fact that there is no temperature increase in your basal body temperature curve and that Daysy will not show you any green days after ovulation (see figure). You can confirm breakthrough bleeding just like real menstruation on your Daysy.

Menstruation during perimenopause

Just like the cycles, the intensity of your menstruation can also vary during perimenopause. In cycles without ovulation, menstruation can be lighter, while menstruation after a long cycle can last longer, often with more blood loss. Studies in women who are in the late phase of the transition to menopause (one to three years before menopause) show that the average blood loss during menstruation after cycles with ovulation is more than double that in the middle years of their fertility (70ml compared to 30 ml)2. According to another study, on average, about 6 of the last 10 cycles in the year before menopause are anovulatory3. This means that during this late phase of perimenopause, approximately 60% of cycles may occur without ovulation.

During this transition phase, Daysy offers you the opportunity to learn more about your body and to consciously experience and shape this stage of your life. With Daysy you can actively follow and better understand the changes that are taking place in your body.

Typical symptoms and changes during perimenopause

Perimenopause, as described, is the transitional phase before menopause proper, when the body gradually stops releasing follicles and the production of hormones such as estrogen and progesterone slowly decreases. During this phase, similar to puberty, various symptoms and changes may occur in the body. Here are some typical symptoms and changes that may occur during perimenopause:

The most common symptoms in perimenopause include: 

  • Irregular menstrual cycles: during perimenopause, menstrual cycles may become irregular. Some women may experience longer or shorter cycles, heavier or lighter bleeding. Some cycles may even go without ovulation.
  • Hot flashes and night sweats: these are probably the best known symptoms of perimenopause and menopause. Hot flashes can cause sudden feelings of heat in the upper body, often accompanied by flushing and sweating. Night sweats can cause sleep disturbances. By the way, hot flashes and night sweats do not affect basal body temperature, so measuring with Daysy is not a problem. You can find more on this topic here.
  • Mood swings: Many women report mood swings, irritability or depression during perimenopause. This may be due in part to the hormonal changes, but also to sleep disturbances due to night sweats.
  • Sleep disturbances: Problems falling asleep or sleeping through the night may occur during perimenopause, often in conjunction with night sweats.
  • Changes in sexuality: some women experience decreased libido or changes in sexual response and sensation. Vaginal health may also be affected, with symptoms such as dryness or discomfort during intercourse.
  • Cognitive changes: Some women report difficulty concentrating or memory problems during perimenopause.
  • Physical changes: Physical changes such as weight gain and change in fat distribution may occur.

What can I do about perimenopause symptoms?

It is important to know that perimenopause is a normal transition process that can sometimes take years. In the first step, it can already be very helpful to deal with the situation, track symptoms and understand what exactly is happening based on the basal body temperature. 

With the symptoms described, a holistic and individualized approach is especially important. Since every woman experiences perimenopause in a different way, it is important to address specific symptoms and overall health. A healthy diet, regular exercise and adequate sleep can be the first step in alleviating individual symptoms.

Although there are no specific vitamins that are exclusive to perimenopause, certain vitamins and nutrients can be helpful. Calcium is important for bone health, while vitamin D aids in the absorption of calcium. Vitamin K plays a role in bone health and blood clotting. Vitamin E may be supportive for menopausal symptoms such as hot flashes. B vitamins, especially vitamin B6, can assist with hormone regulation and mood swings. Magnesium can reduce muscle cramps and sleep disturbances. 

If you suffer from very distressing symptoms that affect your quality of life, medical treatment may be necessary, such as hormone therapy to relieve severe hot flashes or the use of sleep medications for insomnia caused by menopause. These measures aim to provide women with relief and help them cope better with the effects of menopause.

The onion principle

Dressing in layers can help you with hot flashes. By wearing several layers of clothing, you can remove one layer if necessary to lower your body temperature. Once the hot flash is over, you can put the layer of clothing back on. This is especially helpful because a hot flash is often followed by a cold flash. After a hot flash, a functional undershirt that does not absorb moisture may be more comfortable than cotton underwear.

Weight gain

As you reach the age of 30, your body composition changes: less muscle mass is built up, while the proportion of body fat increases. Since muscle burns more energy than fat tissue, the daily basal metabolic rate decreases as a result - this is the amount of calories your body needs to perform its basic functions. To avoid excessive weight gain, it's advisable during perimenopause to make sure you eat a healthy, balanced diet. In addition, you should stay physically active. Sports and other physical activities increase calorie consumption and help maintain and strengthen muscles.

Sleep disorders

Sleep disturbances may be more common during perimenopause due to hormonal fluctuations and other symptoms such as hot flashes and night sweats. Here are some strategies that can help alleviate sleep problems.

  • Good sleep hygiene: try to maintain a regular bedtime and create a quiet, dark and cool sleeping environment. Avoid screens and other electronic devices just before bedtime, as the light from these devices can disrupt sleep.
  • Relaxation techniques: Techniques such as yoga, meditation or breathing exercises can help calm the mind and promote relaxation before bed.
  • Exercise: Regular physical activity can help improve sleep quality. However, try to avoid intense workouts just before bedtime, as the adrenaline released causes additional physical restlessness.
  • Avoid heavy meals and alcohol just before bedtime: Both can disrupt sleep and cause discomfort and digestive problems.

Alternative Therapies

Alternative therapies for menopause have gained popularity in recent years, and one of them is the method of menopause expert Lara Briden4. Lara Briden is a well-known author and health expert who specializes in hormonal health. Her approaches are based on naturopathic principles and a holistic approach to menopause.

Lara Briden emphasizes the importance of a balanced diet, regular exercise and stress management as fundamental pillars of hormonal health during menopause. She recommends a diet rich in healthy fats, whole grains, vegetables and high-quality proteins to provide the body with the nutrients it needs.

In addition to a healthy diet, Lara Briden also recommends certain supplements that can support hormone balance, such as magnesium, omega-3 fatty acids and vitamin B6. She also stresses the importance of a well-functioning digestive system, as it plays a role in hormonal balance.

In addition, Lara Briden emphasizes natural methods for relieving menopause symptoms. These include herbal preparations such as black cohosh and Vitex, which can help with hot flashes and mood swings. However, she stresses that not every woman will benefit from these alternatives and that individualized adjustments may be needed.

It is recommended to consult with a health care professional before using such therapies to consider possible interactions with other medications or individual health concerns. Each woman should weigh her decision to use alternative therapies carefully and consider individual needs and risks.

Hormone Replacement Therapy

Another widely used treatment option for severe menopausal symptoms (link) is hormone replacement therapy (HRT). This therapy consists of taking artificial hormones, specifically estrogen and progesterone, to compensate for hormone deficiencies during menopause. Hormone replacement therapy can be administered in the form of pills, patches, gels, or injections. Hormone replacement therapy can be effective in relieving many of the symptoms of menopause, such as hot flashes, night sweats, vaginal dryness and sleep disturbances. In addition, it may also slow the loss of bone mass (osteoporosis) that can accompany menopause.

However, it is important to note that hormone replacement therapy may also carry risks and side effects. For this reason, it is recommended that hormone replacement therapy be discussed with a health care professional to weigh individual risks and benefits and to tailor treatment to specific needs.

Daysy is an intelligent fertility tracker that lets you get to know your very own menstrual cycle.


1) Prior JC. Perimenopause: the complex endocrinology of the menopausal transition. Endocrine Reviews. 1998 Aug;19(4):397-428.

2) Hale, G. E., Manconi, F., Luscombe, G., and Fraser, I. S. Quantitative measurements of menstrual blood loss in ovulatory and anovulatory cycles in middle- and late-reproductive age and the menopausal transition. Obstetrics and Gynecology , 115(2 Pt 1):249–256, Feb 2010

3) Landgren BM, Collins A, Csemiczky G, Burger HG, Baksheev L, Robertson DM. Menopause transition: annual changes in serum hormonal patterns over the menstrual cycle in women during a nine-year period prior to menopause. The Journal of Clinical Endocrinology & Metabolism. 2004 Jun 1;89(6):2763-9.