Last updated: October 2026
Insomnia before your period is common. In the week or so before a period, progesterone falls and your body runs slightly warmer, which can make sleep lighter and more broken. It usually eases once your period starts. A cool bedroom, a regular routine and treating pain can help. If it’s severe or comes with low mood, see a GP.
Below: why it happens, how common it is, how long it lasts, perimenopause and the pill, what helps, the pregnancy question and when to see a GP.
Why you can’t sleep before your period
A few things tend to stack up in the days before a period.
Falling progesterone
Progesterone rises after ovulation and then drops steeply in the last few days before your period. Progesterone and the substances your body makes from it generally help sleep, so a 2023 review of reproductive hormones and sleep found that this late drop is linked with more broken sleep.
A slightly warmer body
In the second half of your cycle, after ovulation, your core body temperature runs a little higher and its usual daily rise and fall is flatter. Add a warm bedroom, which the NHS lists as a common cause of insomnia, and nights can feel lighter and more restless. Researchers also see slightly less REM (dreaming) sleep in this phase.
PMS symptoms that keep you awake
The NHS lists “tiredness or trouble sleeping” among the most common PMS symptoms, alongside mood swings, anxiety, bloating, cramping, breast tenderness and headaches. Any of these can make it harder to drop off. Worry plays a big part: in one sleep-lab study, women with severe PMS rated their sleep as much worse before their period even though their measured sleep looked fairly normal, and the worse they felt about their sleep, the more anxious they were. If your mind races in bed, see anxiety at night.
PMDD
For a small number of women, symptoms are much more intense. This is premenstrual dysphoric disorder (PMDD), and the NHS lists problems sleeping alongside feeling very anxious, angry, depressed or suicidal. PMDD is treatable, so speak to a GP.
Period pain
Poor sleep before and during a period is more common in women with painful cramps. Treating the pain is one of the quickest wins (see the table below).
How common is insomnia before a period?
Very common, but it doesn’t affect everyone. The NHS says most women have PMS at some point, and trouble sleeping is one of its most common symptoms. Researchers estimate that up to 18% of women have severe premenstrual symptoms, and 3% to 10% meet the criteria for PMDD.
Patterns differ from person to person. When 213 young women tracked their sleep every day for two cycles, some found it harder to sleep around their period, some found it harder mid-cycle, and others noticed no change at all. So whatever your pattern, it’s normal.
How long does it last?
For most people, sleep gets worse in the few nights to a week or so before a period and settles once bleeding starts, as other PMS symptoms do. If you have painful periods, poor sleep can carry on into the first day or two of bleeding.
A few rough nights a month won’t harm you, but they can add up. See sleep debt for how to recover without making it worse. If poor sleep spreads beyond the days before your period, it may be insomnia rather than a premenstrual pattern; the NHS calls insomnia lasting 3 months or longer long-term insomnia.
Perimenopause and the pill
Insomnia before your period in perimenopause
The NHS says a change in your periods is usually one of the first signs of perimenopause, and that sleep problems are common and may be worse with night sweats. So premenstrual insomnia that is new, or much worse than it used to be, can be part of perimenopause. See perimenopause and sleep, the full list of perimenopause symptoms and night sweats.
Insomnia before your period on the pill
The combined pill stops your ovaries releasing an egg each month, and the NHS lists PMS among the things it can help with. The bleed you get in the pill-free break or dummy-pill week is described by the NHS as bleeding like a period. If your sleep changed when you started or switched pill, talk to your GP or sexual health clinic. For other hormone-related causes, see hormonal imbalance symptoms.
What helps insomnia before a period
These steps come from the NHS advice on insomnia and PMS. They work best if you start a few days before you expect sleep to slip, so a period tracker or calendar helps.
| What to try | Why it helps | How |
|---|---|---|
| Keep your bedroom cool | The NHS lists a room that’s too hot as a common cause of insomnia, and you run warmer before a period | Lighter bedding, a window open or a fan |
| Keep the same wake-up time | Steadies your body clock | Get up at the same time every day, and don’t sleep in after a bad night |
| Wind down for an hour | Gives your mind time to slow down | A bath, a book, low light, no phone. See our bedtime routine |
| Treat cramps and headaches | Pain is a common reason for waking | Ibuprofen or paracetamol, as the NHS suggests for PMS pain; ask a pharmacist if you’re unsure. A hot water bottle helps too |
| Cut caffeine and alcohol later in the day | Both disturb sleep | The NHS advises no tea, coffee or alcohol for at least 6 hours before bed. See alcohol and sleep |
| Eat little and often | The NHS advises against a big meal late at night | The NHS suggests smaller meals every 2 to 3 hours for PMS |
| Exercise regularly | Helps both PMS and sleep | Daily movement, but not hard exercise in the 4 hours before bed |
| Calm a busy mind | Stress and anxiety are top causes of insomnia | Yoga, meditation or slow breathing |
| Go to bed only when you’re sleepy | Part of the NHS advice for insomnia | If you’re wide awake, read in low light until you feel drowsy |
| Keep a symptom diary | Shows the pattern and helps your GP | Note sleep, mood and symptoms for at least 2 cycles |
For more ideas, see 12 sleep hygiene habits and how to get more deep sleep.
What about magnesium?
The NHS says supplements such as vitamin B6, calcium, vitamin D and magnesium may help with PMS, but that there isn’t much evidence that they work. We look at the small trials in magnesium for PMS.
Many women like a warm, caffeine-free drink as part of their wind-down in the days before a period. Our Magnesium Glycinate Sleep Complex combines magnesium bisglycinate and citrate with glycine, L-theanine and chamomile. Magnesium contributes to normal psychological function and to the reduction of tiredness and fatigue. For more on why magnesium matters for women, see magnesium for women.
Our products are for adults only. We don’t recommend our products during pregnancy or breastfeeding. Check with a GP or pharmacist before starting a supplement if you take any medicines.
Insomnia before a period or early pregnancy?
You can’t tell from sleep alone. Pregnancy can disturb sleep too, and early signs overlap with PMS: the NHS notes that sore breasts in early pregnancy can feel just as they might before a period, and feeling extremely tired is another early sign.
If your period is late and you could be pregnant, take a pregnancy test. The NHS says most tests work from the first day of a missed period. If the test is negative but your period still hasn’t come, wait a few days and test again, and see your GP if the second test is negative and your period still hasn’t arrived.
When to see a GP
See a GP if:
- changing your sleep habits hasn’t helped
- you’ve had trouble sleeping for months, or it’s spreading beyond the days before your period
- poor sleep or PMS is affecting your daily life, work or relationships
- your periods have changed, or you think you might be in perimenopause
Take your symptom diary. A GP can look for other causes and may suggest cognitive behavioural therapy (CBT) for insomnia, or treatments for PMS such as the combined pill, CBT or antidepressants. GPs now rarely prescribe sleeping pills.
If low mood, anger or anxiety take over before your period, read about PMDD and talk to your GP. If you’re feeling suicidal, call 999 or go to A&E. You can also call Samaritans free, day or night, on 116 123.
If your period is late as well, see can stress delay your period?
If pain is keeping you awake once your period starts, see period pain at night and what helps.
FAQs
Why can’t I sleep before my period?
Progesterone, which generally helps sleep, drops steeply in the days before a period, and your body runs slightly warmer after ovulation. PMS symptoms such as anxiety, cramps and bloating can also keep you awake.
How many days before a period can insomnia start?
Usually in the few nights to a week or so before a period. It tends to ease once bleeding starts, though painful periods can keep sleep broken for a day or two longer.
Is insomnia before a period normal?
Yes. The NHS lists trouble sleeping among the most common PMS symptoms. See a GP if it’s severe, lasts for months or comes with low mood.
Is insomnia before a period a sign of perimenopause?
It can be, if it’s new or getting worse and your periods are changing too. Changes to your periods are usually one of the first signs of perimenopause, and sleep problems are common.
Is insomnia before a period a sign of pregnancy?
You can’t tell from sleep alone, as early pregnancy and PMS share symptoms. If your period is late, take a pregnancy test from the first day of your missed period.
Does magnesium help sleep before a period?
The NHS says there isn’t much evidence that supplements help PMS. Magnesium contributes to normal psychological function and to the reduction of tiredness and fatigue.
Sources
- NHS. PMS (premenstrual syndrome).
- NHS. Insomnia.
- NHS. Doing a pregnancy test.
- Haufe A, Leeners B. Sleep disturbances across a woman’s lifespan: what is the role of reproductive hormones? J Endocr Soc, 2023.
- Baker FC, Lee KA. Menstrual cycle effects on sleep. Sleep Med Clin, 2018.
- Baker FC, Driver HS. Circadian rhythms, sleep, and the menstrual cycle. Sleep Med, 2007.
- Baker FC et al. Perceived poor sleep quality in the absence of polysomnographic sleep disturbance in women with severe premenstrual syndrome. J Sleep Res, 2012.
- Van Reen E, Kiesner J. Individual differences in self-reported difficulty sleeping across the menstrual cycle. Arch Womens Ment Health, 2016.
This guide is general information, not medical advice. Evopure makes the Magnesium Glycinate Sleep Complex.
