Hormones interact together to regulate certain phases of the menstrual cycle. Understanding the different stages of the menstrual cycle is important to help you get familiar and recognise the changes your body is going through and how you may feel during each phase. It is during this cycle that the levels of oestrogen or progesterone rise or fall. So how do your hormones change during the menstrual cycle?
01 What is the menstrual cycle?
The menstrual cycle, otherwise known as the ovulatory cycle, can be defined as the systematic changes occurring in the body that are induced by the action of hormones, especially progesterone, oestrogen, follicle- stimulating hormone (FSH), and luteinising hormone (LH).
These stimulate the reproductive organs to prepare for fertilisation e.g. an eventual pregnancy. In most cycles, ovulation occurs, which is the process by which one of the ovaries releases an egg. If the egg is not fertilised, the lining of the uterine cavity, called the endometrium, is shed and bleeding occurs. This is known as menstruation or a period. Hormones play a key role in this, and they can also affect your moods, emotions and appearance.
02 What happens during your menstrual cycle and how hormones affect your body and mood?
Are you wondering how your body knows when it’s ready for your period? Or why you may experience certain emotional or physical changes a week or so before you menstruate?
It’s all because of the hormone changes during your menstrual cycle. The first day of the menstrual cycle is also the first day of bleeding. The levels of the hormones - oestrogen and progesterone - are at a low level. This is when you usually feel sluggish, sleepy and tired. You may also experience abdominal pain or cramps, have poorer concentration and be more sensitive to pain. You may also notice that the skin is very prone to dryness and flaking and may be easier to be irritated.
Around the 10th day of the cycle, oestrogen levels increase. You may then feel more energy, strength and resilience. You may also become more sensitive to touch. This time is the best for your skin, its elasticity and hydration improve, and it can look more rested and radiant. Progesterone levels rise towards the end of the menstrual cycle, if fertilisation does not occur. The desire for intimacy decreases as oestrogen falls. Then a few days before menstruation you may feel swollen, irritable and sleepy. You may tire more quickly and get headaches, also changes in your mood can occur. At days 1-6 oestrogen is at a very low level. Progesterone levels are getting higher. Some women may develop premenstrual syndrome during this time.
03 Menstrual cycle and hormones
During the menstrual cycle, many changes take place in your body. To understand them better, it is helpful to learn what hormones are, which ones are involved in the menstrual cycle and how they affect your cycle. This will help you have a better understanding of your body and your feelings during your menstrual cycle.
1. What are hormones?
Hormones are natural chemicals in your body. They are produced by glands in the brain and ovaries and tell other parts of your body what to do.
Menstrual cycle hormones have specific regulatory functions and even the smallest amounts can impact your body. They are closely linked to each other. Hormones can affect whether you feel happy or sad, stressed or relaxed, anxious or angry. They are also responsible for metabolism, libido, the development of sexual characteristics during adolescence, the functioning of the reproductive system, and the ability to get pregnant or the regulation of the menstrual cycle.
Understanding the hormonal control of your menstrual cycle is helpful for getting a grasp on what’s going on with your body during puberty and beyond.
2. Which hormones are involved in my menstrual cycle?
There are four hormones involved in the menstrual cycle:
- oestrogen
- progesterone
- luteinising hormone (LH)
- follicle- stimulating hormone (FSH).
Luteinising hormone and follicle- stimulating hormone are produced by the pituitary gland in the brain that controls the menstrual cycle by promoting ovulation and stimulating the ovaries to produce oestrogen and progesterone.
Changes that occur in your oestrogen and progesterone levels during your menstrual cycle can have effects on your body and emotions. You might experience breast tenderness, bloating, headaches, food cravings or tiredness. You might also have days where hormonal changes make you feel more confident and ready to take on new challenges!
3. How do these hormones affect my menstrual cycle?
Variations in menstrual cycle hormone levels account for the difference in menstrual cycle lengths. This is because each body is slightly different, fluctuating in how much hormones are produced and when.
The average menstrual cycle is anywhere between 21 to 35 days. There can however be a lot of variability in your cycle length, particularly in the first few years after your first period.
04 Hormones during menstrual cycle
The menstrual cycle is divided into several phases, including menstruation, the follicular phase, ovulation and the luteal phase. During the cycle, menstrual cycle hormone levels continually rise and fall.
Female hormone cycle chart
Changes in hormone levels are best demonstrated by the below hormone cycle chart.
During the first days of the cycle, known as menstruation, (days 1-5), hormone levels drop. The endometrium begins to be shed and leaves the body with the menstrual blood. The ovarian follicles begin to redevelop. The low levels of oestrogen and progesterone can also affect your mood.
In the next phase, known as the follicular phase, occurs around days 6-13 of the cycle. You may notice that any abdominal cramps or other discomforts disappear. The follicles of the ovary grow and they release increasing amounts of oestrogen.
Ovulation occurs around day 14 of the cycle. This is when the highest concentration of oestrogen occurs. Between days 15 and 20 of the cycle, known as the luteal phase, oestrogen levels are still high. When the ovarian follicle loses its egg, it turns into a mass of cells in your ovary known as the corpus luteum, which begins producing progesterone. If fertilisation does not occur, between days 21 and 28 of the cycle, oestrogen and progesterone levels drop.
05 Menstruation (Day 01 - 07)
The first day of your period is Day one of your menstrual cycle. This is when the menstrual cycle hormone levels are at their lowest.
At the start of the menstrual cycle, when hormone levels are low, the pituitary gland releases a hormone called follicle- stimulating hormone. This hormone helps prepare an egg for release by stimulating some ovarian follicles to grow and produce oestrogen.
Prompted by the low levels of oestrogen and progesterone, the lining of your uterus (endometrium) breaks down and leaves your body through the vagina, as a reddish fluid. This is your period.
06 Pre-ovulation - The Follicular Phase (Day 08 - 13)
In the second phase of your menstrual cycle, your ovaries start producing more of the follicle-stimulating hormone (FSH), which makes your period lighter until it stops altogether. Oestrogen starts to rise as the ovarian follicles grow.
During this time the endometrium gets thicker as it prepares for a potential pregnancy. The follicular phase ends at the onset of ovulation. The time before and after ovulation is referred to as the fertile days. This is the period when a woman has the best chance of becoming pregnant. They start about 5 days before ovulation and end about 2 days after.
07 Ovulation and post-ovulation (Day 14 - 24)
On Day 14 of a 28-day cycle (or 14 days before the next period), a peak in ovulation hormones makes the ovarian follicle release an egg, a process known as ovulation. The process is driven by a significant increase in oestrogen levels. This hormone stops the release of FSH and at the same time stimulates the release of the LH hormone. Right after ovulation starts, the empty follicle (where the egg was released) turns into something called the corpus luteum, a temporary collection of cells involved in the regulation of hormones levels. Thanks to the LH hormone, the corpus luteum starts making progesterone and continues producing oestrogen, just like the follicle did before.
This egg travels along the fallopian tube and can survive for up to 24 hours - during which time fertilisation can occur. If a sperm fertilizes the egg, a baby will start to develop.
08 Pre-menstruation - The Luteal Phase (Day 25 - 28)
The next part of the female hormone cycle is called the luteal phase. This is when progesterone levels rise, and oestrogen levels drop.
Progesterone’s job is to thicken the lining of your uterus in preparation so that the egg you release during ovulation can successfully attach (if it was fertilised) and grow inside your uterus. On Days 21 to 24, progesterone reaches its peak.
After this, if your egg is not fertilised, progesterone levels start to drop, signalling to your body to start breaking down the lining of your uterus, as it is no longer needed.
This is when you may start to experience symptoms of PMS (premenstrual syndrome).
Read more here about PMS, what it is, and how to manage it.
Then, your body starts all over again with Day 1 of your menstrual cycle.
