Sleep & Hormones: Resetting Your Routine as Days Shorten
As the bright days of summer fade into the coziness of fall, it’s common to notice subtle shifts in your energy, mood, and even your menstrual cycle (not to mention overwhelming cravings for a good ‘ole PSL). The earlier sunsets and longer nights don’t just mean lighting candles sooner in the evening. Instead, this shift directly influences your circadian rhythm and hormone balance.
If you’ve ever felt like you need more sleep, crave heavier comfort foods, or just feel a little “off” emotionally as the seasons change, you’re not imagining it. Your body is responding to real biological changes. But once you understand how daylight, sleep, and hormones interact, you can make simple, nourishing adjustments that help you feel grounded, balanced, and in rhythm with your body this fall.
The Connection Between Daylight, Sleep, and Hormones
Your Circadian Rhythm: Nature’s Internal Clock
Your circadian rhythm is your body’s built-in 24-hour clock. It helps regulate not just when you feel awake or sleepy, but it also affects hormone release, digestion, body temperature, and yes, even fertility.The biggest influence on your circadian rhythm is light, which is why the shift to shorter days in fall and winter can leave your body feeling more than a little out of sync.
When daylight decreases, your brain naturally makes more melatonin, the hormone that tells your body it’s time to rest. While melatonin is essential for deep, restorative sleep, too much of it, especially during the day, can leave you feeling groggy sluggish. At the same time, less sunlight means less serotonin, your feel-good neurotransmitter, which can take a toll on both mood and motivation.
Hormones Most Affected by Shorter Days
Melatonin: Rises earlier in the evening and stays elevated longer, making you feel tired sooner.
Cortisol: Your natural “get-up-and-go” hormone may peak later in the morning, leaving you with slower starts and affecting energy and focus.
Serotonin: Lower levels can contribute to mood changes, cravings, and even symptoms of seasonal affective disorder (SAD).
Reproductive Hormones: Because circadian rhythm and sleep directly influence the hypothalamic-pituitary-ovarian (HPO) axis, changes in light and sleep can subtly affect ovulation, cycle regularity, and PMS symptoms.
Why Sleep Matters for Hormone Balance & Fertility
Quality sleep is one of the most overlooked pillars of hormone health. Poor or inconsistent sleep can disrupt the delicate balance of estrogen, progesterone, insulin, cortisol, and thyroid hormones, all of which play a role in fertility and overall well-being.
For Women Trying to Conceive
Ovulation: Sleep disturbances can affect luteinizing hormone (LH) surges, which trigger ovulation.
Progesterone: Low-quality sleep is linked to lower progesterone during the luteal phase. Since progesterone is crucial for implantation, this can make conception more challenging.
Stress & Cortisol: Poor sleep raises cortisol, your main stress hormone, which competes with reproductive hormone production.
For Every Women’s Health
Even if pregnancy isn’t your current goal, restorative sleep still deserves a front-row seat in your wellness routine. Consistent, deep rest supports:
More stable moods
Balanced energy throughout the day
Smoother, more predictable cycles
Stronger digestion and gut health
In short: quality sleep is one of the most powerful ways to actually feel like your best self.
Resetting Your Routine as the Days Shorten
One of the beautiful things about a functional medicine approach is that even small, intentional shifts can create a big ripple effect in your sleep, hormones, and fertility. As the seasons change, think of this as an opportunity to gently realign your body with the natural rhythm of fall.
Here are a few ways to get started:
1. Maximize Morning Light
Your circadian rhythm runs on light cues and the most powerful signal comes in the morning. Aim to step outside within 30–60 minutes of waking, even just 10–15 minutes of natural sunlight can make a difference. If you’re up before the sun, a light therapy box can help mimic daylight and support your body’s internal clock.
2. Keep Evenings Dim
Fall evenings invite cozy routines, but screen time can sneak in, too. The blue light from phones, TVs, and laptops sends your brain mixed signals, making it harder to release melatonin and wind down. Try:
Wearing blue-light–blocking glasses after sunset
Switching your lamps and overhead lights to warm, softer lighting
Setting a gentle screen “curfew” at least an hour before bed
3. Anchor Your Sleep & Wake Times
Your body thrives on consistency. Heading to bed and waking up around the same times each day (yes, even on weekends) helps strengthen your circadian rhythm. This consistency makes it easier for your body to release hormones at the right times, which supports everything from deeper sleep to steadier energy during the day.
4. Support Sleep with Nutrition
The foods you eat can be powerful allies in supporting your circadian rhythm:
Magnesium-rich foods like pumpkin seeds, leafy greens, and dark chocolate help calm the nervous system.
Tryptophan-rich foods like tofu, oats, and nuts support melatonin production.
Balanced blood sugar (pairing protein, fiber, and healthy fats at each meal) prevents those 2 a.m. cortisol spikes that can jolt you awake.
5. Incorporate Gentle Movement
Movement improves sleep quality, steadies cortisol, and supports insulin sensitivity. In fall, consider swapping late-night HIIT sessions for grounding activities like yoga or walking after dinner, so that you’re more calm than stimulated as bedtime approaches.
6. Manage Seasonal Mood Shifts
If shorter days leave you feeling a little down, know that you are definitely not alone and that there are simple, supportive practices that can help:
Use light therapy in the morning to boost serotonin
Prioritize daily outdoor time (yes, even when it’s cloudy!)
Try calming mind-body practices like meditation, breathwork, prayer or journaling to lower cortisol and support reproductive hormone balance
Functional Medicine Testing for Sleep & Hormone Balance
Sometimes, even with the best habits in place, you can still struggle with sleep issues, hormone imbalances or just feeling like something is “off”. That’s where functional testing can be incredibly helpful. Instead of guessing, these tools uncover the root causes of sleep and hormone imbalances, giving us a clear picture of what your body truly needs. For example:
DUTCH Test: Offers a detailed look at your cortisol rhythm, melatonin production, and sex hormone balance. (Curious if the DUTCH test is right for you? I wrote a full guide here that breaks it down in detail).
Comprehensive Nutrient Panel: Reveals deficiencies in key nutrients like magnesium, B vitamins, or iron, all of which play a role in sleep quality and energy.
Thyroid Testing: Identifies whether thyroid hormones are contributing to fatigue, mood shifts, or cycle changes. (Learn more about thyroid health and fertility in my post here.)
Testing takes out the uncertainty, allowing us to create a plan that’s personalized and targeted to you so you can stop wondering if you’re doing things right and start supporting your body with confidence.
Embracing Seasonal Rhythms
Rather than fighting against shorter days, consider this season an invitation to slow down, reconnect, and reset. The longer evenings offer space to rest, build nourishing rituals, and support your hormones in finding balance. By leaning into this seasonal shift, you not only protect your fertility and energy now, but also strengthen your resilience for the months ahead.
Final Thoughts
As the days grow shorter, your body is making subtle yet powerful adjustments on a hormonal level. By honoring your circadian rhythm and weaving in small, intentional changes, you can support your fertility, balance your hormones, and move through fall feeling grounded and energized.
If you’re ready to dive deeper into your hormone health and want a plan that’s personalized to your body and goals, I’d love to support you. You can learn more about my services here, or schedule a consultation below.
