As the mornings get darker and colder and the days grow shorter, it’s easy to blame the outside world for our changing mood, lower energy level and lack of focus. But here’s the thing – it’s not just the weather. Your hormones are shifting too.
The seasonal transition into Autumn affects key hormones like cortisol, serotonin, melatonin and even your reproductive hormones – all of which play a huge role in how you feel day to day.
So if you’ve noticed your motivation dipping or your cravings creeping in, you’re not imagining it. There are both psychological and physiological reasons behind these changes. As the world around us slows down, our bodies and minds are simply trying to adjust to the new rhythm of the season.
What Happens to Your Hormones in Autumn?
As the light fades and the temperature drops, your body quietly starts to recalibrate. It’s all part of nature’s rhythm – and your hormones are front and centre in this seasonal adjustment.
Here's what’s really going on behind the scenes:
☀️Serotonin Takes a Dip
Less sunlight means your body produces less serotonin, the “feel-good” hormone responsible for keeping your mood steady and your motivation high. That’s why the Autumn blues are very real – your brain chemistry is literally reacting to the darker days.
🌙 Melatonin Rises
As daylight hours shrink, your body increases melatonin production – the hormone that regulates sleep. More melatonin can make you feel sleepier earlier, slow your mornings down and leave you craving extra rest (and maybe that third coffee).
⚖️ Cortisol Fluctuations
The shift in routine and reduced daylight can subtly change cortisol levels, your main stress hormone. Darker mornings may mean your cortisol isn’t spiking at the right time, leaving you feeling sluggish and foggy-headed. Then, as the day goes on, your body might try to compensate – spiking cortisol later in the afternoon or evening. That can make it harder to unwind, fall asleep or feel truly relaxed. Over time, these shifts can throw off your natural rhythm, energy levels and even appetite.
🌞Vitamin D Levels Drop
Although it’s called a vitamin, Vitamin D acts more like a hormone, regulating mood, immunity, and reproductive hormones. Our greatest source is sunlight, so as days shorten, levels naturally start to dip. Low Vitamin D can reduce serotonin production and subtly affect PMS, energy and overall hormonal balance.
💕 Reproductive Hormones React
Because your endocrine system works as one connected network, shifts in serotonin, melatonin or cortisol can influence your oestrogen and progesterone balance. That’s why you might notice more intense PMS symptoms, changes in cycle length or mood swings as the seasons change. Low Vitamin D can amplify these effects, making autumn a season where gentle self-care and nutritional support really matter.
How This Feels Day-to-Day
⚡Energy Highs & Lows
With serotonin dipping and melatonin rising, you might find mornings sluggish and afternoons unexpectedly drained. That 9-to-5 feels longer, your workouts require more effort and even small tasks can feel like a mountain.
🥴 Mood Swings & Emotional Sensitivity
Lower sunlight, fluctuating cortisol, and changes in reproductive hormones can leave emotions more intense than usual. Feeling irritable, tearful or more anxious than normal? It may be your body’s way of adjusting to the season.
🍬 Cravings for Comfort Foods
When cortisol and serotonin are out of sync, your body may crave carbs, chocolate or sweet treats (we have a whole blog on this!). These cravings are more than just habits – they’re your body trying to boost serotonin naturally.
As temperatures drop, many people also notice an increase in appetite, particularly for carbohydrates and high-calorie foods. This isn’t just a random craving – it’s an evolutionary response. Eating helps generate internal heat, raising body temperature and during colder months, your body works harder and burns more energy just to keep you warm. Your desire to eat more is a natural signal that your body needs extra fuel to maintain energy and stay cozy.
💤 Sleep Changes
Shorter days and rising melatonin levels can make you feel sleepier earlier in the evening, or leave you tossing and turning if your cortisol spikes later in the day
💕 Cycle-Related Symptoms Intensify
PMS symptoms or hormonal sensitivities may feel amplified. Low Vitamin D, stress and lifestyle changes all play a role – making autumn a season to prioritise self-care and hormone-friendly habits.
Supporting Your Hormones Naturally
Autumn doesn’t have to leave you feeling off-balance. There are simple, everyday ways to support your hormones and help your body adjust to the seasonal shift.
🌞Boost Your Vitamin D
With shorter days and less sunlight, your Vitamin D levels can drop, affecting mood, energy and reproductive hormone balance. Try to get outside for natural sunlight when possible, include Vitamin D-rich foods like fatty fish or fortified options and consider a Vitamin D supplement to keep levels steady.
🧘🏼 Manage Cortisol & Stress
This half of the year can be stressful – whether it’s end-of-year deadlines, exams or the fast approaching holiday season. Cortisol fluctuations during these times can leave you feeling either wired or completely drained. Simple practices like mindfulness, journaling, gentle exercise, yoga or focused breathing can help regulate stress levels.
🥗 Nourish Your Body
Focus on nutrient-dense meals that keep your body fuelled and your hormones happy. Combine complex carbohydrates with protein, healthy fats and fiber to help maintain stable blood sugar, which supports energy, mood and hormone balance. Avoid long gaps between meals – this not only keeps your energy steady but can also help curb cravings for high-calorie comfort foods.
💕 Support Your Reproductive Hormones
Nutrients like B6, zinc, magnesium and omega-3 fatty acids support progesterone and oestrogen balance, which can help with PMS and overall hormonal stability. Incorporating these through diet or targeted supplements can make the seasonal shift easier on your body.
Autumn Hormone Takeaway
Autumn is your body’s gentle reminder to slow down, reset and care for yourself. The shorter days, cooler temperatures and seasonal changes naturally affect hormones like cortisol, serotonin, melatonin and your reproductive hormones – which can impact everything from your mood, energy, cravings and sleep.
The good news? With small, intentional steps, you can support your hormones and feel your best this season. Prioritising Vitamin D, nourishing meals, stress management, balanced blood sugar and quality sleep can make a big difference in how you feel day to day.
Think of it like this: your body isn’t working against you – it’s just adapting to the rhythm of the season. Lean into this natural shift and give yourself the care you need to glide through Autumn with energy, balance and ease.