The Menstrual Cycle Phases Explained

The Four Different Phases and How Each Affects Your Well Being

Some of this article may get a little scientific in its explanations but stick with us. Once you get the general understanding of the four phases of your menstrual cycle you will feel much more empowered, prepared and knowledgeable about the way your body operates.

Controlled by several different glands and the hormones that these glands produce, the workings of our menstrual cycle can be complex. The average length of the menstrual cycle is 28 days, but this can vary from woman to woman and from one cycle to the next. The length of the menstrual cycle is calculated from the first day of your period to the day before the next period starts. Apart from preparing your body for pregnancy, these hormonal fluctuations have some serious repercussions on your mind, body and emotions. We’ll show exactly what’s going on in your head throughout the (approximately) 28 days of your cycle.


Day 1 to Day 5 Menstruation (Your Period)

According to Dr. Louann Brizendine, a neurobiologist at the University of California, and author of The Female Brain, hormonally speaking, the first day of bleeding is a relatively quiet time. At this stage your brain and your body’s levels of the three major hormones that regulate your cycle—estrogen, progesterone, and testosterone—are about as low and balanced as they’ll be during this entire month.

When a surge in hormone-like compounds called prostaglandins begins, this is when cramps or nausea can begin as your uterus releases its unfertilized egg and any extra blood or tissue that accumulated as your body prepared for pregnancy. The body also begins to create more estrogen and testosterone as your period proceeds, although levels of both are still relatively low, this again according to Dr. Brizendine. That extra release of estrogen stimulates the release of feel-good compounds like endorphins, which remove any leftover crankiness or foggy thinking you may have experienced during PMS.


Day 5 to Day 14 Follicular Phase

Starting now, the estrogen hormone levels will being to climb sharply until just before you start ovulating in order to prepare your uterus for fertilization. “Estrogen acts like fertilizer for brain cells,” Dr. Brizendine says. Now here comes a nice side effect. This fertilizer causes a 25 percent growth of synaptic connections in your hippocampus. In normal person talk this translates to you having increased short-term memory capabilities and stronger decision-making skills. We can also add the sharpening of verbal fluency abilities. Dr. Brizendine joking advises, “I always tell my female students to plan to take their oral exams the day before ovulation, when there estrogen levels are peaking.”

During the Follicular Phase testosterone production is also increased thus intensifying a woman’s sex drive. Combined with the swell of brain activity from estrogen, that leaves you feeling more social, flirtatious, mentally sharp, and energetic. As Mother Nature is working her hardest to keep the species going you may also feel, act and dress in a more ‘look at me’ type of manner. This testosterone injection comes with a side of competition sensation, which can mean you might feel more jealous or threatened by other women and well as working harder to get the man you have your eye one.

One more little scientific fact nugget related to estrogen, it could also affect your sense of smell. Remember all those cartoons and cheap perfumes advertised to mimic male pheromones? Well they really exist and we become more attuned to them during this phase. These chemicals trigger sexual desire during this week before ovulation. Let’s just say it’s a bit amazing how estrogen can change our behavior.


Day 14 Ovulation

If you are on a typical 28-day cycle, ovulation occurs on day 14. However, most women have different menstrual cycle lengths. In general, ovulation happens 11 to 16 days before your upcoming period. At this time, your body reacts by lowering self-control (this has been proven by researchers I swear!). As a result, you might find yourself attracted to more masculine looking faces, and you’re more likely to engage in risky sexual behavior.

Ovulation is technically defined as one of the ovaries releasing a mature egg. The egg travels out to the nearest fallopian tube and into your uterus. As the egg moves down the fallopian tube over three to four days, the lining of the uterus continues to grow thicker. Now the egg waits for roughly 24 hours in hopes of being fertilized before it starts degenerating.

Studies issued out of Germany have shown that the high amounts of estrogen we produce, increase grey matter in our brain, particularly in the hippocampus. That may improve our memory and our ability to process information. Unfortunately, once ovulation has begun, those hormones drop again, then leaving us feeling cranky.

Now a different hormone, progesterone starts to kick in. This one acts on the same brain receptors that a prescription muscle relaxer does, meaning we get an overall feeling of calm. Progesterone prepares the uterus for implantation of a fertilized egg (if there happens to be one).

Unfortunately, as your ovulation ends and your progesterone levels continue to rise, your hippocampus and the other parts of your brain become less active, meaning your short-term memory, verbal fluency, and general sociability may all fall. The same German research as mentioned above also states that your brain’s grey matter stores will shrink as well.


Day 15 to 28 Luteal Phase

When pregnancy does not occur, the body prepares to remove the unfertilized egg. Progesterone and estrogen levels radically drop at this time too. This then starts a chain reaction causing an increase in stress chemicals like cortisol. This is not so great as it can contribute to your bad mood during PMS. Headaches, poor sleep, and a general absence of energy and enthusiasm are all pretty common side effects.

For those who experience severe PMS mood swings, your hormone levels might be especially high. But look on the bright side, in just a few days, this whole roller-coaster hormone cycle will start all over again (yay!). Your estrogen levels will pick up as your period begins and the awful PMS symptoms will disappear like that box of chocolate you devoured last week.


1 Comment
  1. This was really helpful. Learned a whole lot a didn’t know. Thanks for sharing!

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