Menstruation and Tiredness – why am I so exhausted on my period?

Image by Caroline Taporda via Dupe.

We've all been there – it's day two of your period and you feel like you could sleep for a(nother) solid 12 hours, even though you just woke up. Or maybe you're staring at your laptop screen wondering why simple tasks suddenly feel so much more difficult than they did a few days ago. Sound familiar?

This exhaustion is incredibly real and affects millions of women and people who menstruate. "Most women say that their menstrual cycle affects their sleep in some way", says Dr. Linda Schachter, Medical Director of Sleep Services Australia. "Around menstruation, women find that it is harder to get to sleep and stay asleep," she adds.

This is known as period fatigue and it's incredibly common; and, there are solid physiological reasons why. From hormonal fluctuations, to blood loss and sleep disruptions, your body is working overtime during the menstrual phase of your cycle. The exhaustion you feel is real, valid, and completely normal. Let's dive into why it happens and what you can do about it.

WHY DO PERIODS MAKE YOU SO TIRED?

It's all about what's happening inside your body during this time. The hormones oestrogen and progesterone levels plummet just before and during your period, which can leave you feeling like you've been hit by a truck.

But it's not just hormones causing the chaos. During menstruation, you're literally losing blood (and iron along with it), which can contribute to feelings of fatigue and weakness. Your body is also dealing with inflammation as it sheds the uterine lining, which requires energy and can leave you feeling drained.

Sleep often takes a hit too – whether it's cramps keeping you awake, bloating making you uncomfortable, or anxiety about leaks disrupting your rest. Poor sleep quality naturally leads to next-day exhaustion. Add in the emotional and physical stress that can come with your period, and it's no wonder you feel like you could sleep for a week straight.

UNDERSTANDING PERIOD FATIGUE AND ITS CAUSES

Tiredness during period isn't just caused by one thing. It's often driven by a perfect storm of factors working together to zap your energy. Let's break down the main culprits behind exhaustion during menstruation:

Iron deficiency is a big one. You're losing blood every month, and with it goes iron – an essential mineral for carrying oxygen around your body. Low iron means less oxygen to your muscles and brain, resulting in that sluggish, tired feeling.
Poor sleep is another major player in period causing fatigue. Hormonal changes, physical discomfort from cramps or bloating, and even anxiety about your period can all mess with your sleep quality. When you're not getting restorative sleep, daytime fatigue is inevitable.
Premenstrual syndrome (PMS) brings its own set of energy-draining symptoms. Mood swings, food cravings, breast tenderness, and irritability all require mental and physical energy to manage.
Inflammation is also at play – your body's natural response to shedding the uterine lining can trigger inflammatory processes that leave you feeling run down and achy, similar to how you might feel when fighting off a cold.
Stress can be both a cause and consequence of period fatigue. The physical stress of menstruation on your body, combined with any emotional or life stressors, can drain your energy reserves. "Increased stress causes increased cortisol, which can also affect your ability to fall asleep, stay asleep, or your sleep quality, with more frequent arousals through the night," explains Dr. Schachter.

Let's further unpack a couple more key culprits...

SLEEEP DISRUPTIONS DURING YOUR PERIOD

Hormonal shifts in the days leading up to and during your period can throw off your natural sleep-wake cycle. "Changes in oestrogen and progesterone affect the ability to fall asleep, stay asleep and also reduce sleep quality," says Dr. Schachter.

Physical symptoms don't help either – period cramps, bloating, breast tenderness, and that general feeling of discomfort can make finding a comfortable sleeping position feel impossible. Then there's the mental load: worrying about leaks, feeling anxious about pain levels, or dealing with mood changes can keep your mind racing when you should be winding down. Ensuring you're using reliable, quality and comfortable period care you can trust, like an overnight pad or period cup (which can provide 12hr wear) helps alleviate the overnight leak anxiety, meaning there's one less thing to worry about.

Poor sleep quality directly contributes to tiredness during period, creating a frustrating cycle where you're tired because you can't sleep well, but you can't sleep well because of period symptoms. This is "why am I so tired on my period?" becomes such a common question.

The good news? It's not forever. "It's important to remember that the disrupted sleep or insomnia is usually not a long-term issue, so it's going to settle once your mentrual cycle is over," says Dr. Schachter. "This may mean that you have less frustration and anxiety about your sleep," she adds.

Understanding the connection between sleep and your period is the first step to breaking the cycle. Simple sleep hygiene practices and relaxation techniques can make a real difference (more about those further on). If it ever gets too much, or thigns don't seem to be improving post period, check in with your doctor.

HORMONAL CHANGES AND FATIGUE

The relationship between menstruation and tiredness is deeply rooted in your hormones. Right before your period starts, both oestrogen and progesterone take a dramatic nosedive. These aren't just "period hormones", but major players in regulating your energy, mood, and overall wellbeing.

Oestrogen helps maintain steady energy levels and supports the production of serotonin, your body's natural mood stabiliser. When oestrogen drops, serotonin can drop too, leading to that sluggish, low-energy feeling. Progesterone, which has a naturally sedating effect, also plummets, which might sound like it would make you more energetic, but the sudden withdrawal can actually leave you feeling even more fatigued.

This hormonal rollercoaster affects everything from your sleep patterns to your metabolism, explaining why you might feel like you're running on empty during your period. Your body is essentially recalibrating itself, and that process takes serious energy.

WHAT IS MENSTRUAL BRAIN FOG?

Period brain fog is a real phenomenon linked to those same hormonal fluctuations causing your fatigue. When estrogen levels drop, it affects neurotransmitters in your brain that are crucial for memory, concentration, and mental clarity. It's like your brain's processing power has been temporarily reduced (you know - that feeling when your brain feels like it's wrapped in cotton wool, or when you can't remember where you put your keys, when you struggle to focus on simple tasks, or find yourself reading the same sentence three times without taking it in).

Symptoms of menstrual brain fog include difficulty concentrating, forgetfulness, feeling mentally "slow," trouble finding words, and that general sense that your thoughts are moving through treacle. Some people describe it as feeling disconnected from their usual sharp mental state.

The good news is that period brain fog is temporary and directly linked to your cycle. As your hormones stabilise after your period, that mental clarity typically returns. Understanding that this is a normal part of menstruation can help reduce the frustration and self-criticism that often comes with these cognitive changes.

WHEN TO WORRY - IS PERIOD TIREDNESS EVER A MEDICAL CONCERN?

While period fatigue is normal, there are times when extreme tiredness might signal something more serious that needs medical attention. If your exhaustion is so severe that it's significantly impacting your daily life, work, or relationships, it's worth having a chat with your healthcare provider.

Heavy menstrual bleeding can lead to iron deficiency anemia, which causes profound fatigue that goes beyond typical period tiredness. Other red flags include fatigue that doesn't improve after your period ends, shortness of breath, dizziness, or pale skin.

Conditions like endometriosis, polycystic ovary syndrome (PCOS), or thyroid disorders can also cause severe period-related fatigue. Endometriosis, in particular, can cause inflammation throughout your cycle, leading to chronic exhaustion.

If you're experiencing extreme fatigue alongside other concerning symptoms like very heavy bleeding, severe pain, or significant mood changes, don't hesitate to seek medical advice. Your doctor can run blood tests to check for anemia, thyroid issues, or other underlying conditions that might be contributing to your exhaustion.

HOW TO MANAGE PERIOD FATIGUE: PRACTICAL TIPS

The good news is that there are plenty of ways to combat period fatigue and support your energy levels during menstruation. Here are some practical, science-backed strategies:

Prioritize iron-rich foods like spinach, lean red meat, lentils, and dark chocolate (yes, really!). Pair them with vitamin C sources like citrus fruits or bell peppers to boost absorption.
Stay hydrated – dehydration can worsen fatigue, so aim for plenty of water throughout the day. Herbal teas (like our Moxie FLO TEA, specially Naturopathically blended with PMS in mind) can be particularly soothing and contribute to your fluid intake.
Sync with the light "In the morning, it's important to be exposed to lots of natural light, and reduce light exposure (i.e. phones and bright TVs) at night before bed," suggest Dr. Schachter. "It's also important to go to bed at the same time and get up at the same time each day," she adds.
Gentle movement might feel counterintuitive when you're exhausted, but light exercise like walking, stretching, or gentle yoga can actually boost energy levels and improve mood.
Rest without guilt – your body is working hard during your period, so give yourself permission to slow down. Take naps if you need them, go to bed earlier, and don't feel bad about saying no to extra commitments.
Manage stress through meditation, deep breathing, or whatever relaxation techniques work for you. Stress can worsen period symptoms and drain your energy even further.
Consider magnesium supplements (after checking with your healthcare provider) as they may help with sleep quality and muscle relaxation.

Check out our detailed post that delves further into what you can do if you're having trouble sleeping on your period.

TRACKING SYMPTOMS TO BETTER UNDERSTAND YOUR CYCLE

One of the most powerful tools for managing period fatigue is understanding your own patterns. Dr. Schachter advises that "if your sleeping problems are related to your menstrual cycle, it's important to track your cycle so that you can anticipate when the problems are likely to occur." You can then plan ahead accordingly.

Use a period tracking app or simple journal to note your energy levels, sleep quality, and mood each day. After a few cycles, you'll start to see patterns emerge – maybe you always feel exhausted two days before your period, or perhaps your energy crashes on day two of bleeding.

This information is incredibly valuable for both self-care and medical discussions. You can schedule lighter days when you know you'll be tired, stock up on iron-rich foods before your energy dips, or adjust your exercise routine to match your cycle.

FINAL THOUGHTS

Understanding the connection between menstruation and tiredness is a crucial part of period literacy. Your exhaustion isn't weakness, but your body responding to significant hormonal and physical changes. The fatigue you feel is valid, normal, and manageable with the right strategies. If it feels like it's getting too much at any point, or if you're ever unsure of anything, check in with your doctor or healthcare practitioner.

Remember, every person's experience with periods is different. What works for your friend might not work for you, and that's perfectly okay. Be patient with yourself as you figure out what helps you feel your best during your cycle. Your period doesn't have to derail your life – with understanding and the right tools, you can navigate period fatigue with confidence and self-compassion.

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NOTE: just like the discussions had and info provided on TikTok, the information provided here is intended to educate and inform only, and does not constitute medical advice or replace a personalised medical diagnosis from your GP or a medical professional. The aim is to inform and encourage you to get to know your flow and your body, and get checked if things seem off in any way.