Why do I get insomnia before my period?

In the luteal phase, rising then falling progesterone and a slightly higher body temperature make sleep lighter and more broken, so many women have their worst nights in the days before their period.

Is cyclical insomnia normal?

It’s common and usually harmless, but it shouldn’t be dismissed if it’s wearing you down. Tracking it against your cycle helps you and a doctor see the pattern and decide whether to treat it.

How can I tell if my insomnia is hormonal?

Map your sleep against your cycle for a couple of months. If bad nights reliably cluster in the same phase and ease when your period starts, that timing points to a hormonal driver.

Sleep

Why does my insomnia come and go every month?

Quick answer

If your insomnia seems to switch on and off in a monthly rhythm (a few bad nights that then settle, month after month) it's very likely linked to your cycle. Sleep tends to get lighter and more broken in the luteal phase, the week or so before your period, when progesterone rises then falls and your body temperature runs slightly higher. It's one of the most overlooked patterns in women's sleep, because night to night it looks random. Tracked against your cycle, the timing usually lines up.

What might be happening

After ovulation, progesterone climbs and nudges your core body temperature up, which can make it harder to fall and stay asleep. Then, in the days before your period, progesterone and estrogen drop sharply, and that withdrawal is linked with more night-time waking, lighter sleep and early waking. For many women the worst nights cluster in those few pre-period days.

PMS and perimenopause both amplify it. Anxiety, a racing mind, cramps and night sweats often arrive in the same window and fragment sleep further. So a run of bad nights that then resolves as your period starts isn't a coincidence, it's a hormonal pattern repeating each cycle.

What to notice

Which cycle days the bad nights fall on (map them against your period)
The type of disruption: trouble falling asleep, waking in the night, early waking, night sweats
Whether it eases once your period starts
What else shows up that week: anxiety, cramps, low mood, cravings
Caffeine, alcohol, stress and room temperature on the same nights

Log your sleep alongside your cycle for two or three months. If the disrupted nights repeat in the same phase, you can start to plan for them rather than being caught out.

Related patterns

Women whose insomnia comes and goes with their cycle often also track premenstrual mood changes, brain fog, cramps, night sweats and daytime fatigue in the same phase.

When to get support

If disrupted sleep is frequent, leaving you exhausted, or paired with low mood, talk to a doctor. If the pattern is severe and clearly premenstrual, ask about PMS or PMDD; if your cycles are also changing, ask about perimenopause. Persistent insomnia is treatable, you don’t have to wait it out.