All About Period Brain Fog & What You Can Do To Help

A young woman with short dark hair holds her hand to her forehead, with an exhausted face.

Many of us, in the days leading up to our periods, may find that we begin to feel a bit out of sorts in terms of concentration, memory, and making decisions. No, it’s not just you. What you’re experiencing is actually called period brain fog, and it’s only really starting to be looked at as a topic when talking about women’s health.

But what is period brain fog? What causes it? And perhaps most importantly, how do you get rid of period brain fog when it becomes too much in the time leading up to your most delicate days?

In this article, we'll look into the definition of period brain fog, the common symptoms many women experience, and some tips and tricks that may help you manage it more effectively. 

So, what is period brain fog?

Period brain fog is a condition that causes people to feel forgetful, indecisive, or sluggish at certain points in their menstrual cycle. It’s a common symptom of premenstrual syndrome (PMS). However, brain fog can also be a symptom or side effect of certain health conditions, such as chronic fatigue syndrome, or through various mental health disorders.

Research on brain fog and periods is currently very limited, but many women on menstruating age have shared their experience of brain fog, which appears related to their menstrual cycle. Some health professionals dismiss period brain fog, and although it hasn't been proven to be a unique medical condition, some research exists into the possible causes of it.

PMS has been identified and accepted by medical professionals as a cluster of symptoms relating to hormone changes in the body due to a woman's menstrual cycle. According to the NHS, common symptoms of PMS include mood swings, tiredness, and trouble sleeping — all of which can be linked to the experience many women have of period brain fog. 

In the neuroscientific journal Endocrine Reviews, Barbara B Sherwin posted that the hormone oestrogen (which is normally at its lowest level during menstruation) can be used to treat and prevent cognitive decline. Therefore, it's possible that the fluctuating oestrogen levels which. occur around the menstrual cycle, could affect cognitive function and be responsible for the phenomenon of brain fog.

Again, research into period brain fog is limited and ongoing, but many women have identified this as an issue significant to their lives, and their mental health.

What affects can period brain fog have?

Women who believe they suffer from the phenomenon of period brain fog often describe the toll it takes on their daily life. Some effects of period brain fog include, but are not limited to:


Women may feel absent-minded, or have a tendency to forget things at different parts of their menstrual cycle. This can lead to feelings of frustration, as well as causing issues at school, work, or as part of a person's family life, if important things slip the person's mind.


Many who experience brain fog report feeling tired, burnt out, or exhausted — even after what appears to be a good night's sleep. This tiredness can affect everyday tasks, and make activities like going to the gym or socialising seem more draining or difficult.


Some people who struggle with period brain fog may feel disconnected from people, or even the world around them. Feelings of tiredness may cause some people to withdraw, and avoid social situations. They may struggle to pay attention to when people speak to them, feel distracted, or just feel a general disinterest in conversation.

Low mood

Brain fog, and period brain fog, have been associated with low mood in individuals. They may feel bored, fatigued or even unhappy, without a clear understanding. Although period brain fog is temporary, and normally lasts only a few days, periods of low mood can be very difficult for people. For those who already suffer from mental health conditions, such as anxiety or depression, the additional low mood brought on by PMS can be truly devastating., 

Causes of period brain fog

Whether experts are looking into the issue or not is really beside the point. People are getting brain fog before, during, and just after their periods. 

Here are some of the causes that researchers have found to explain the symptoms of PMS, which may well relate to the phenomenon of period brain fog.

Hormonal imbalances

The most common reason for getting PMS, and potentially brain fog, before a period, is hormonal imbalances, specifically in your sex hormones. During the second half of your menstrual cycle, you’ll have elevated levels of progesterone compared to your levels of oestrogen. In the days leading up to your period, both of these will fall. In turn, this impacts other hormones and neurotransmitters, often lowering levels of serotonin and increasing levels of cortisol. These hormones help regulate mood and your sense of “alertness”, so when they’re all over the place, you’re likely to feel that way.


If you suffer from anaemia, you’re also more likely to experience brain fog before your period. This is because your blood lacks the healthy red blood cells needed to transport oxygen around your body, meaning your brain won’t receive enough oxygen. This may often lead to you feeling dizzy or fatigued, and will often get worse before your period starts. 

As your body loses blood during your period, it’s likely that the brain fog stemming from anaemia will continue.

Poor sleep or insomnia

PMS often comes with poor sleep, or bouts of insomnia, which may be caused by hormonal fluctuations during the luteal stage of the menstrual cycle. These have been shown to disrupt sleep patterns and cause fragmented sleep, causing people to sleep poorly and wake up not feeling as sharp as they might have been before.

If you suffer from particularly bad cramps or have a heavy period, it’s possible this may continue past the luteal phase, as the pain may keep you awake at night. This loss of sleep could also be a significant factor, which contributes to the feeling of period brain fog in your waking hours. 

Anxiety and depression

Both depression and anxiety have the potential to cause brain fog, because of altered chemical production in the brain and how they manifest. Depression, for example, manifests as feelings of numbness, sadness, and apathy ‒ all of which are common feelings to experience when going through a spell of brain fog. 

Anxiety, on the other hand, often takes up a lot of mental energy because of the intrusive thoughts the person is dealing with. It can also impair their thinking and ability to concentrate, which may be worse if they get overwhelmed and feel even more unable to focus. 

Coming up to a period may exacerbate these particular symptoms, as the levels of hormones affecting your moods will drop. Researchers have identified links between depression and PMS, and found evidence that symptoms of depression can be heightened and made more serve by premenstrual stress. One study, conducted by SK Padhy et. al, and published in the Indian Journal of Psychological Medicine, was just one supporting source for this hypothesis. 


Different medicines and drugs list tiredness, poor concentration, and brain fog as some of their side effects, including antidepressants, antihistamines, and some types of cancer treatments. If medication is the cause of your period brain fog, it may worsen a bit before your period starts, but it shouldn’t fluctuate too much at any other time. It may be that the changes in your hormone levels have a temporary effect on how your medication works within your body, leading to listed symptoms such as brain fog or poor concentration to become more severe.


Your brain needs a lot of energy to stay working at its best, and it gets this energy from nutrients, vitamins, and minerals. It needs a lot more of it if you’re preparing for your next menstrual cycle too! If you aren’t getting the right food for this to happen, then there’s a chance you won’t have enough energy for your brain to function just how it should.

If you have any food sensitivities, there is a chance that you may feel sluggish after you’ve eaten something that would normally trigger you. Similarly, if you have a slow metabolism, you might also experience brain fog after eating. However, if you do experience a slow metabolism, your brain fog and fatigue should also be consistent and not linked to PMS.

Other PMS symptoms

Sometimes, you’ll find that your other PMS symptoms are impacting how alert and present you feel. For example, if you’re being bothered by mood swings, have constant food cravings, or are distracted during your day by painful cramps, you may not be paying as much attention as possible to other things. If you're looking for ways to manage your PMS, which don't include taking medication, check out our article for some natural remedies to help reduce the effects of PMS on your daily life.

Getting brain fog after your period

While many know about getting a brain fog before or during your period, not many realise it’s possible to get brain fog after your period. This is all part of what’s known as post-menstrual syndrome, during which your iron levels will drop. Even a small decrease in the amount in your body can cause fatigue and brain fog, alongside irritability and aches, and these symptoms may last for a few days after your period is over.

Post menstrual syndrome typically isn't discussed as much as pre menstrual syndrome, which is recognised by various medical organisations, including the NHS. However, many women also experience post menstrual syndrome, which refers to a cluster of common symptoms individuals experience only after their period ends.

To find out more about post menstrual syndrome, you may like to read the following article by Healthline: Everything You Need to Know About Post Menstrual Syndrome. 

How to get rid of period brain fog:

There are a few things you can do to help alleviate your brain fog, and to lead a healthier lifestyle that should help you to have an easier period:

  • Make sure you’re eating healthily; eat plenty of fruits and vegetables, lean proteins, and things low in fat. Try to ignore cravings for sweet or salty things!
  • Avoid taking in too much alcohol or caffeine
  • Try to sleep well; set yourself a sleep schedule and limit brain stimulation (e.g. scrolling through your phone or watching television) before you try to rest.
  • Get some light exercise during the day to stimulate both your body and your brain (taking a nice walk is particularly good for this, and it will help you sleep better at night).
  • Avoid stress wherever possible
  • Make sure you’re getting the right vitamins, such as B group vitamins, Zinc, and omega fatty acids (for your brain), Vitamin D (for your moods and concentration), and Magnesium (for your nervous system)
  • Speak to your doctor to make sure you haven’t got any undiagnosed medical issues, such as anaemia, or different hormonal imbalances

If these suggestions don’t help with the brain fog around your period, it may be necessary to speak with your doctor again to try something else. They should be able to discuss potential treatment options with you, or refer you to a specialist.

Planning ahead for your period:

At fluxies, we believe in being prepared for every period, no matter what you can expect from the days before, during, and after your cycle. This is why our fabulous sets of period pants come in designs and styles that are just right for any kind of blood flow! 

Whether your periods are heavy or light, last a few days or a full week, we've got the perfect pair to keep you resh and clean throughout your cycle. Our ultra soft, absorbent period pants come in a wide range of designs, from briefs to boxers, and even our discreet period thongs. You won’t even have to think too hard about what to do with them once they’ve been worn ‒ just bung them straight in the wash, hang them up to dry, and then put them away for next time!

You’ll even be covered in the event our undies are not for you, with our 60-day money-back guarantee. So, what are you waiting for? Buy up a pair or two (or three) for your next period and give them a go ‒ see how comfortable they make your cycle!