The female cycle is a natural, recurring process that prepares a woman's body for pregnancy. This cycle is regulated by a finely tuned interplay of hormones, each playing a distinct role in different phases. The main hormones involved are estrogen and progesterone, which, along with other hormones, ensure the smooth functioning of the cycle. Understanding these hormones and their functions can help you better grasp what’s happening in your body.
The phases of the female cycle
The female cycle is divided into four phases:
Menstrual phase: This phase begins on the first day of your period. During menstruation, the uterine lining is shed because pregnancy has not occurred. Your body then prepares to start a new cycle. Many women experience fatigue, cramps, or mood swings during this time.
Follicular phase: The follicular phase begins alongside menstruation and lasts until ovulation. During this phase, estrogen levels rise significantly, stimulating the growth and maturation of eggs in the ovaries. The increasing estrogen levels often lead to a boost in energy, improved mood, and a radiant complexion.
Ovulation phase: Ovulation marks the peak of the cycle. Around the middle of the cycle, a mature egg is released from the ovary due to a surge of luteinizing hormone (LH). LH triggers ovulation. During this phase, body temperature may increase slightly, and many women notice a heightened sexual desire.
Luteal phase: After ovulation, the luteal phase begins, during which progesterone takes center stage. This hormone prepares the uterine lining for potential implantation. If pregnancy does not occur, progesterone and estrogen levels drop, and the cycle starts anew. In this phase, just before menstruation, symptoms like mood swings, breast tenderness, or increased appetite can be more pronounced.
The menstrual cycle: (FSH = Follicle-stimulating hormone, LH = luteinizing hormone)
The figure shows how hormone levels change throughout the menstrual cycle. Estrogen rises during the follicular phase, FSH and LH promote egg growth and release. Progesterone dominates the luteal phase, preparing the uterine lining for implantation, and decreases if no pregnancy occurs. The drop in progesterone and estrogen leads to menstrual bleeding. Cycle length (28 days) and bleeding duration (3-5 days) vary individually, usually ranging from 21-35 days for the cycle and 2-7 days for bleeding.
The figure also shows follicle growth. A follicle contains an egg that matures during the follicular phase. The follicle grows under FSH until it becomes mature. In the middle of the cycle, an LH surge triggers ovulation, releasing the egg. After ovulation, the empty follicle becomes the corpus luteum, which produces progesterone. If there is no fertilization, the corpus luteum regresses.
How long is a “normal” cycle – and does it really exist?
The answer is not so simple. A “normal” cycle can last anywhere from 21 to 35 days, and the often-quoted 28-day cycle is more of a guideline than the rule. Many women experience slight variations in cycle length from month to month. These fluctuations are entirely normal and depend on various factors such as age, stress, diet, or lifestyle. So, there is no absolute “normal.” The key is to monitor your own cycle, observe its regularity, and note any changes – you are the expert on your body!
Cycle-related discomforts
The cycle doesn’t just involve hormonal changes but can also bring a variety of symptoms. Many women experience pain during menstruation, ranging from mild cramps to severe pain that impacts daily life. Premenstrual syndrome (PMS) is relatively common and can add symptoms such as irritability, headaches, food cravings, or sleep disturbances. If these symptoms are regular, pronounced, or impact your everyday life, PMS may be at play.
"On some days, it was so bad that I could barely get out of bed. I wanted to see a doctor, but even the thought of leaving the house felt overwhelming in those moments."
– Lea, 28
The strength and duration of bleeding can vary from cycle to cycle. Some women experience very heavy periods, known as menorrhagia. Another condition that can greatly impact the cycle is endometriosis, where tissue similar to the uterine lining grows outside the uterus, leading to severe pain and irregular cycles. However, there are approaches to relieve symptoms, from pain management and hormonal treatments to surgical interventions in severe cases. It’s important to take these symptoms seriously and seek support from our Evela experts when needed.
Hormonal effects outside of reproductive organs
There are millions of hormone receptors throughout the body, not only in reproductive organs but also in the brain, bones, cardiovascular system, and skin. Hormones like estrogen and progesterone, therefore, influence many other areas of your body. Estrogen, for example, helps maintain bone density, supports skin elasticity, and impacts memory and mood in the brain. When hormone levels drop during menopause, many women notice not only common symptoms like hot flushes but also issues with memory (sometimes called “brain fog”) and mood swings. This shows how extensively these hormones affect the whole body.
Who else experiences cycles and menopause?
The female cycle is not exclusive to humans. Many mammals also have a reproductive cycle. Interestingly, only a few animals, such as whales (like orcas), go through menopause similarly to humans. This means that after their reproductive phase, they can live many years without having offspring – a rare exception in the animal kingdom.
Effects of hormonal contraceptives on the cycle
Contraceptive methods like the birth control pill or hormonal IUD (intrauterine device) have a direct impact on the female cycle:
The “classic” pill is a combination of estrogen and a progestin (a synthetic form of progesterone) and prevents ovulation. It stabilizes hormone levels, often leading to lighter and more regular bleeding.
The mini pill contains only a progestin (no estrogen) and has similar effects to the classic pill.
Hormonal IUDs release hormones locally in the uterus, often resulting in very light or absent bleeding. Besides hormonal IUDs, there are also copper IUDs, which release copper ions to prevent pregnancy. IUDs provide long-term contraception, usually effective for 3–5 years (sometimes up to 10 years).
Depending on the symptoms and the type of contraceptive, these methods are not only effective for birth control but can also help manage symptoms like severe menstrual pain or heavy bleeding. Your gynecologist is the best person to help you find the method that suits you.
Non-hormonal contraceptive methods
Contraception is not limited to hormones and medications. There are several non-hormonal methods that are also effective.
Contraception is not “women’s responsibility”
Contraception is not solely the responsibility of women. Men play just as important a role! It’s long overdue to view contraception as a shared responsibility. Some countries are actively researching hormonal contraceptive methods for men, but until these are widely available, condoms remain a reliable option. Don’t hesitate to discuss this openly – contraception is a shared responsibility!
Another non-hormonal option is the temperature method. This natural method is based on daily body temperature measurement to determine fertile and infertile days in the cycle. Just before ovulation, the temperature slightly rises, helping you identify the fertile days. This method, however, requires regular and precise cycle tracking and is best for women with a stable cycle. It is less reliable than hormonal methods or condoms, so consider this carefully if you wish to avoid pregnancy with certainty. Book an appointment with your Evela expert here and receive solutions tailored to you.
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Sources:
Gesundheitsinformation.de https://www.gesundheitsinformation.de/wie-funktioniert-der-weibliche-zyklus.html
Bundeszentrale für gesundheitliche Aufklärung (BZgA) https://www.familienplanung.de
Deutsche Menopause Gesellschaft e.V. https://www.menopause-gesellschaft.de
NHS (National Health Service, UK) https://www.nhs.uk/conditions/contraception/
Robert Koch-Institut (RKI) https://www.rki.de