Understanding the Menstrual Cycle: Phases, Hormones and Nutrition

The menstrual cycle is a vital component of women’s health, influencing everything from fertility and energy to digestion, mood, and sleep. While commonly associated with reproduction, the cycle is also a powerful indicator of overall well-being and hormonal balance. Understanding its phases can help you work with your body rather than against it, allowing you to meet your needs with more compassion and clarity.

In this article, we’ll explore the four phases of the menstrual cycle, the key hormones involved, and how a balanced, consistent approach to nutrition and lifestyle can help support hormonal health and promote better physical and emotional well-being.

What Is the Menstrual Cycle?

The menstrual cycle refers to the monthly hormonal process that prepares the body for a potential pregnancy. Although the average cycle length is 28 days, it can range from 21 to 35 days in healthy individuals. The cycle is governed by a complex interplay between the hypothalamus, pituitary gland, ovaries and uterus.
If pregnancy does not occur, hormone levels fall and the body sheds the uterine lining, resulting in a period. But the menstrual cycle is more than just menstruation, it's a dynamic, cyclical process that impacts nearly every system in the body.

The Four Phases of the Menstrual Cycle

Each phase of the menstrual cycle is marked by distinct hormonal patterns that influence how we feel, function and fuel. Understanding these shifts can help us adapt how we care for ourselves, physically, mentally and nutritionally, across the month.

Key Hormones Involved in the Menstrual Cycle

To understand the menstrual cycle, it helps to get to know the four main hormones that orchestrate it. Each one plays a unique role in regulating ovulation, menstruation and overall hormonal balance.

Oestrogen: Oestrogen is often referred to as the "growth" hormone. It helps build the uterine lining (endometrium) after a period, supports egg maturation in the ovaries, and influences mood, bone health, skin, cardiovascular health and brain function. It tends to make us feel more energised, confident and sociable when at its peak.

Progesterone: Progesterone is the calming, stabilising hormone that rises after ovulation. It supports the uterine lining to prepare for a possible pregnancy and plays a role in regulating mood, sleep and body temperature. If pregnancy doesn't occur, progesterone drops, triggering the start of a new cycle (your period).

Follicle-Stimulating Hormone (FSH): FSH is released by the pituitary gland in the brain and stimulates the ovaries to grow and mature follicles (each containing an egg). It’s most active in the early part of the cycle, during the follicular phase.
Luteinising Hormone (LH): LH surges mid-cycle and triggers ovulation which is the release of a mature egg from the ovary. It also helps the ruptured follicle transform into the corpus luteum, which produces progesterone during the second half of the cycle.

1. Menstrual Phase (Days 1–5)

This is the start of the cycle and begins on the first day of bleeding. During this phase, oestrogen and progesterone are at their lowest, and the body sheds the uterine lining.
What You Might Notice:

Menstrual bleeding
Cramps or low back pain
Fatigue
Sensitivity to stress and mood changes
 

Nutritional Considerations

This is a time for replenishment and nourishment. Focus on iron-rich foods such as red meat, lentils, tofu and spinach to replace what's lost through bleeding. Combine plant-based iron sources with vitamin C-rich foods like peppers or citrus to enhance absorption. Magnesium-rich foods, such as leafy greens, dark chocolate, and seeds, can help ease cramps by supporting muscle relaxation. Prioritise hydration with water and herbal teas to help with energy and reduce bloating.

2. Follicular Phase (Days 1–14)

This phase overlaps with menstruation at the start and continues until ovulation. Follicle-stimulating hormone (FSH) encourages the growth of ovarian follicles, and oestrogen begins to rise, rebuilding the uterine lining.
What You Might Notice:

Increased motivation and energy
Enhanced mental clarity
Improved skin appearance
Lower appetite

Nutritional Considerations

As oestrogen rises, this is a great time to focus on nutrient-dense, whole foods to support hormone production and clearance. Cruciferous vegetables like broccoli, kale and cabbage help the liver metabolise excess oestrogen. Fermented foods such as kefir, yoghurt and sauerkraut support gut health, which plays a key role in hormone regulation. Include healthy fats from nuts, seeds, olive oil and oily fish to support cell health and hormone synthesis.

3. Ovulatory Phase (Around Day 14)

Ovulation marks the release of a mature egg in response to a surge in luteinising hormone (LH). This is the body’s most fertile window and typically lasts 24–48 hours.
What You Might Notice:

Boosted confidence and sociability
Increased libido
Cervical mucus becomes clear and stretchy
A slight rise in body temperature

Nutritional Considerations

Your body’s energy demands peak here, so fuel it with complex carbohydrates like oats, brown rice, and root vegetables to support blood sugar balance. Combine these with lean proteins such as chicken, eggs, tofu, and legumes, for satiety and muscle repair. During ovulation, your body experiences increased metabolic activity, which can lead to the production of free radicals (unstable molecules that cause oxidative stress). While this is a normal part of the process, including plenty of antioxidant-rich foods like berries, seeds, and nuts can help protect your cells from this oxidative stress. Additionally, folate-rich foods (leafy greens, citrus fruits, beans) support your body in case conception happens, as folate is vital for early fetal development and reducing the risk of neural tube defects.

4. Luteal Phase (Days 15–28)

After ovulation, progesterone rises to support a potential pregnancy. If fertilisation doesn’t occur, progesterone falls, leading to menstruation. This phase is often associated with PMS symptoms due to hormonal shifts.
What You Might Notice:

Mood changes and irritability
Increased hunger and cravings
Bloating or fluid retention
Fatigue or disrupted sleep
Breast tenderness

Nutritional Considerations

This is the phase where many women feel more vulnerable to emotional and physical fluctuations. Prioritise foods rich in vitamin B6 (bananas, chickpeas, potatoes) and magnesium (pumpkin seeds, leafy greens, dark chocolate) to support mood and reduce bloating. Choose fibre-rich carbohydrates such as lentils, sweet potatoes, wholegrains to help stabilise energy and manage cravings. As appetite often increases, it’s important not to restrict; instead, focus on nourishing meals and snacks that are satisfying and blood sugar-stabilising. Anti-inflammatory foods like berries, oily fish and turmeric can also help ease symptoms.

Supporting Hormonal Health Through Nutrition and Lifestyle

While the menstrual cycle is driven by hormones, how we eat, move, rest and manage stress can profoundly influence how it feels. Across all four phases, eating regularly and enough is key. Skipping meals or under-eating can amplify hormonal imbalances, disrupt blood sugar, and worsen symptoms like fatigue, cravings, and mood swings.

Foundational Strategies for a Balanced Cycle:

Eat Balanced Meals: Prioritise meals that include a source of protein, complex carbohydrates, healthy fats and a variety of colourful vegetables. 
Stay Hydrated: Aim for consistently pale yellow urine as a sign your body is well hydrated. Herbal teas such as peppermint, chamomile or ginger can support digestion and relaxation.
Manage Stress: Chronic stress impacts the hypothalamic-pituitary-ovarian (HPO) axis and can disrupt the menstrual cycle. Practices like mindfulness, breathwork, prayer, journalling and gentle movement can support nervous system balance.
Move Your Body: Regular movement improves circulation, supports detoxification, balances mood and aids hormone metabolism. Rather than following rigid rules, tune into the different phases of your cycle and how they affect your energy and needs. Some people may prefer gentler movement like yoga or walking during menstruation, while others feel strong enough for strength training. You might feel more energised during the follicular and ovulatory phases and naturally lean into more intense workouts. Most importantly, listen to your body. Let movement be a form of self-connection that is flexible, responsive, and supportive of how you feel throughout the month.
Prioritise Sleep: Quality sleep is essential for hormone repair and regulation. Aim for 7–9 hours of uninterrupted sleep per night. Evening wind-down routines and limiting screens before bed can make a big difference.
Track Your Cycle: Using an app or journal to track symptoms, mood, energy and appetite can empower you to spot patterns and make informed lifestyle adjustments.
Know what's not normal: While some discomfort is expected, severe pain, extremely heavy bleeding, missing periods, cycles shorter than 21 days or longer than 35, or symptoms that interfere with your daily life are not things you have to just live with. These may be signs of underlying conditions such as PCOS, endometriosis, fibroids, hypothalamic amenorrhoea or thyroid imbalances, which require personalised and often holistic support. If you're experiencing these symptoms, it’s important to seek care from a qualified healthcare provider. You deserve to feel well and supported throughout your cycle.

Final Thoughts

Although we have a growing understanding of how the menstrual cycle affects various aspects of health and wellbeing, there is still much to learn about the individual variations and long-term impacts. More research is needed to explore how different lifestyle factors, nutrition, and exercise interact with each phase of the cycle. 
Understanding the rhythms of your cycle allows you to take a more intuitive, supportive approach to self-care. Rather than expecting yourself to be the same every day, recognising the shifts in your hormones and adapting your nutrition and habits accordingly can lead to greater ease, energy, and emotional resilience.
Remember: food is not just fuel, it's information for your hormones. Eating enough, eating consistently, and choosing nutrient-rich foods across the month is one of the most powerful ways to support your cycle and your overall health.

Sources: 
https://pmc.ncbi.nlm.nih.gov/articles/PMC10316899/
https://journals.sagepub.com/doi/10.1177/17455057231185624
Not Just a Period by Dr Hazel Wallace (book) 
https://www.sciencedirect.com/science/article/abs/pii/S0378432010004148?via%3Dihub