Your female cycle is controlled by a lot of hormones but the two best known are: oestrogen and progesterone. They are two important sex hormones in women. These hormones, together with other hormones such as FSH and LH, ensure that eggs can mature, jump and implant properly during fertilisation.
Your cycle starts on the first day of your period. On average, this lasts between 3 and 7 days.
After your period, oestrogen starts to increase in your body. During this period, called the follicular phase, small follicles on the ovary begin to develop. Towards the middle of your cycle, one of these follicles will develop into a full-sized egg.
In each cycle, an egg is released from one of your ovaries: this is called ovulation. The level of oestrogen in your body rises in the days before the peak of luteinising hormone (LH).
Oestrogen helps prepare your body for ovulation by thickening the uterine wall and also creates a sperm-friendly endometrium. The increase in oestrogen signals the start of your period of high fertility, which usually lasts four or more days.
Healthy men are fertile every day but women only a few days a month. The greatest chance of pregnancy is if you have sex around the days you are fertile.
The sperm cells of the man stay alive longer than the egg cell of the woman (up to 3-5 days). Therefore, you have the chance to be fertilised up to 3 days before and 2 days after your expected ovulation. Depending on your goals, it is best to have sex during this period or to use contraception if you want to avoid children.
New chief in town.
From the second half of your cycle (after ovulation) progesterone is in charge. The amount of oestrogen then decreases and the progesterone level increases. If the egg is not fertilised, progesterone decreases again and the accumulated endometrium is shed. This is the start of your period and the beginning of your next menstrual cycle.
Some women experience physical as well as emotional symptoms before or during their periods. The severity of the symptoms varies greatly from one woman to another.
Women who suffer from premenstrual syndrome (PMS) have an increased sensitivity to hormonal fluctuations between oestrogens and progesterone.
PMS often involves a surplus of oestrogen in the body. Typical symptoms are mood swings, fatigue, irritability, anxiety, cramps, acne, anger, sleep disturbances, sore breasts, bloating and/or binge eating.
Often these symptoms are labelled as part of being a woman, but it doesn't have to be that way. Read in this article how diet and exercise can have a positive influence on your cycle.
The two female protagonists.
Oestrogen also known as the 'feel good' hormone is produced in the ovaries, but fat cells can also produce the hormone. The production of this hormone only starts in puberty.
Estrogen plays an important role in regulating the menstrual cycle, pregnancy and other body processes such as:
- Strong bones
- Radiant and healthy skin
- Emotional stability
- Good brain functions:
- Estrogen increases the amount of serotonin in the brain. Serotonin affects your mood, sleep, libido and eating behaviour.
- Estrogen influences the production of endorphins. Endorphins are primarily painkillers, but they also cause a feeling of happiness or euphoria.
A good balance of oestrogen helps you feel good about yourself.
Progesterone is made in your ovaries and adrenal glands. In the adrenal glands, it plays a role in the production of the stress hormones cortisol and adrenaline.
Progesterone prepares your body for a possible pregnancy and ensures good blood flow to the uterus so that the egg can nestle.
During pregnancy it ensures that your baby can grow optimally and safely.
If the egg is not fertilised, progesterone decreases again so that menstruation eventually starts at the end of the luteal phase.
A good balance of progesterone contributes to a stable blood sugar level and has a calming and stabilising effect on your brain.
At the end of the luteal phase (read more about the different phases here) progesterone will suddenly drop and you may experience certain complaints as a result.
At the beginning of a pregnancy progesterone will continue to rise and this may also be the reason why you are tired in the beginning of a pregnancy.
An imbalance between oestrogen and progesterone can disrupt your menstrual cycle. This can lead to an irregular cycle or even no menstruation at all.
Progesterone and estrogen balance is crucial to feeling good, having a regular cycle and preparing for a healthy pregnancy.
If you want to learn more about how nutrition and exercise affect your cycle and hormones, read about it here.