Why Some Women Sleep Worse Before Their Period, and What Research Says You Can Do About It

Ever notice that your sleep crashes right before your period starts? You're not imagining it, and you're definitely not alone. Many women experience lighter sleep, more tossing and turning, and early wakeups during the luteal phase of their menstrual cycle. Two well-documented studies help explain why.

Let’s break it down and give you practical ways to manage it.

The Luteal Phase: What’s Happening in Your Body

The menstrual cycle has two main halves:

• Follicular phase (starts on day 1 of your period)

• Luteal phase (begins after ovulation, around day 14, and ends when your period starts)

  
  

During the luteal phase, progesterone rises significantly. This hormone supports a possible pregnancy but also affects sleep regulation, particularly by increasing core body temperature and interacting with the brain's GABA system, which influences calmness and sleep.

As the luteal phase progresses, progesterone then sharply drops, especially right before menstruation. That crash can lead to more fragmented sleep, increased wakefulness, and lighter sleep stages.

Study #1: Sleep Quality Suffers in the Luteal Phase

Published in Health Psychology, 1997 PMID: 9152698

This study followed 32 healthy women across two full menstrual cycles, tracking their sleep-wake patterns through detailed daily logs.

Here’s what they found:

• Sleep Onset Latency Increased: Women took significantly longer to fall asleep during the luteal phase compared to the follicular phase.

• Sleep Efficiency Decreased: The ratio of time asleep versus time in bed dropped.

• Subjective Sleep Quality Worsened: Women reported feeling less rested and more disrupted—even those who didn’t report typical premenstrual symptoms.

  
  

The researchers concluded that “the luteal phase is associated with measurable, cyclical sleep disturbances that are not necessarily tied to PMS diagnosis.”

Study #2: Hormones, Body Temperature, and Sleep Architecture

Published in Journal of the Endocrine Society, 2023 PMID: 37091307

This newer review pulled together data on reproductive hormones and their impact on sleep quality across a woman’s lifespan.

Key takeaways:

• Increased Core Body Temperature: Progesterone raises resting body temp during the luteal phase by ~0.3 to 0.5°C. Since a drop in body temp is essential for sleep onset, this may explain difficulty falling asleep.

• Reduced REM Sleep: Some women experience less REM (dream) sleep, which can reduce sleep satisfaction.

• Sleep Fragmentation: Even in the absence of conscious awakenings, women may cycle through lighter sleep stages more frequently during the luteal phase.

• Higher Risk of Insomnia-Like Symptoms: Especially in women with heightened hormonal sensitivity or underlying conditions like PMDD.

  
  

How to Prepare for Poor Sleep During the Luteal Phase

Instead of fighting it, prepare for it. Here are science-backed ways to improve sleep during this hormonal rollercoaster:

1. Track Your Cycle

Use a period-tracking app or journal. Knowing when your luteal phase begins helps you anticipate disrupted sleep and adjust your habits.

2. Cool Your Sleep Environment

Since core body temperature is elevated, cooling the bedroom helps. Use a fan, keep the thermostat around 65°F (18°C), and opt for breathable sheets.

3. Cut Off Caffeine Earlier

You may be more sensitive to stimulants during the luteal phase. Consider avoiding coffee and other stimulants after noon to minimize delayed sleep onset.

4. Prioritize Wind-Down Routines

Aim for consistency with a 30–60-minute calming routine: no screens, low lighting, meditation, a warm (not hot) shower, or reading.

5. Nutritional Support

Some studies suggest magnesium, vitamin B6, and omega-3s can reduce PMS symptoms and improve sleep quality. Talk to your healthcare provider about supplementation.

6. Practice Self-Compassion

This isn’t “bad sleep hygiene”, it’s biology. Accepting that some nights will be harder helps reduce anxiety about sleep, which ironically helps you sleep better.

Final Thoughts: Work With Your Cycle, Not Against It

The research is clear: hormonal changes during the luteal phase, especially rising and then crashing progesterone, can disrupt sleep through effects on body temperature, brain chemistry, and sleep architecture.

But understanding this gives you power.

By aligning your sleep habits with your body’s natural rhythm, you can reduce the impact, improve rest, and feel more in control.