The woman's cycle: Ovulation, PMS, hormones, sex drive and energy levels 

t's no secret that women's cycles and rising and falling hormone levels are to blame for a lot when it comes to mood and several women have probably heard the comment "is it that time of the month?". You should definitely not make that comment, but there is no doubt that women's hormones actually go up and down significantly depending on where you are in your cycle.

In this article, we review how the sex hormones change during the cycle and how they can affect how you feel both physically and mentally.

Progesterone and estrogen

There are two sex hormones that go up and down during a natural cycle. Progesterone and estrogen. Progesterone is produced in the follicles of the ovary and together with estrogen it helps to make the uterus receptive to a possibly fertilized egg. This happens by increasing the blood supply, so that the mucous membrane produces more thick mucus, in which a possibly fertilized egg can get stuck.

The level of progesterone is highest after ovulation, while it is lowest in the period from menstruation to ovulation. If you as a woman do not produce enough progesterone (normal level after ovulation is 20-100 nmol/L, but the level after menstruation is below 5) then it can mean that it is very difficult to get pregnant, as it can mean that you not ovulating. Read more about ovulation here: If you are worried about whether you are not producing enough progesterone, a blood test carried out a week before menstruation can give you an answer)

Estrogen is produced in the woman's ovaries and has the function in the cycle of building up the lining of the uterus, where a possibly fertilized egg must be able to attach. In women, the hormone increases when you go through puberty, while it decreases when you go through menopause and are no longer fertile. 

Cycle and hormones

Week 1 menstruation, fatigue and lack of energy

Week 1 starts on the day the woman gets her period. Day 1 of the cycle is therefore the first day of menstruation. At this time, the ovaries produce very little estrogen and no progesterone. Here, many will experience that they have menstrual pains and the breasts may feel sore and heavy. Here, many women find that they are tired, perhaps a little depressed and drained of energy.

The low production of hormones is detected by the pituitary gland in the brain, which produces the follicle-stimulating hormone (FSH) and the ovulatory hormone luteinizing hormone (LH). In an average cycle, the period lasts 5 days and when the period is about to finish, the brain will once again cause estrogen levels to start rising

Week 2 Higher energy levels, increased sex drive and ovulation

Now the woman's period is over and estrogen levels continue to rise. This means that many people experience having more energy and being in a better mood. Here the sexual drive will also increase in many women, and there is a reason for that. At the end of week 2 around day 14, if you have an average cycle of 14 days, ovulation will occur. If you want to be pregnant, it is therefore also this week when the woman is most fertile. In this way, the brain and the body are really smart, because now is the time to have intercourse if you want to be pregnant. If you want to use ovulation tests to be sure of catching your ovulation, then you can read more about when you should start testing in the article here: How to test for ovulation and when to start testing? – Gravidtid

Just before ovulation, the brain will turn down the FSH hormone, which started the production of estrogen, and then instead the ovulatory hormone LH will be turned up. The LH hormone will cause the mature follicle to burst and the woman will ovulate and is therefore at the most fertile time in the cycle. If you are using an ovulation test because you want to get pregnant, your ovulation test will now be positive. Because the estrogen level was turned down when the LH hormone was turned up, many women will experience a slight downturn around ovulation.

After ovulation, the body will get ready to receive a fertilized egg. A mucous membrane has grown, and the body will produce the sex hormone progesterone, which must make the mucous membrane stable and prevent bleeding, so that the egg can attach itself to the uterus and develop into a pregnancy.

Week 3 calm state of mind and perhaps a little drained of energy

The woman's progesterone level is still high, while the estrogen level is now falling. This means that many women during this period feel calm and safe, because progesterone can have this calming effect, while others can feel a little depressed and a little drained of energy.

Week 4 PMS

We have now reached the last days until the next period (unless the woman has become pregnant) And in the last days before the period, the body has completely stopped producing estrogen and progesterone. The marked decrease in the production of sex hormones affects many women and you get Premenstrual Syndrome, also called PMS. It is characterized by headaches, joint pain, lack of energy and sex drive, fluctuating mood and in some almost a depressive state.

After a few days, the lack of progesterone will mean that the woman will have her period (unless she has become pregnant) and when the period starts, a new cycle will begin. With all that it implies, for better or for worse, of rising and falling sex hormones and mood. If you have a desire to become pregnant, the time is approaching when you can test for pregnancy. You can read more about that here: When can you test for pregnancy with a pregnancy test? – Gravidtid

Furthermore, a study published last year showed that the menstrual cycle is the factor that has the greatest influence on a woman's mood. The study is based on 3.3 million women who have used the app Clue to record changes in mood in relation to menstruation and cycle. Read more about the study here: Nature Human Behaviour