Cortisol and your hormonal cycle

Cortisol: the stress hormone that governs your cycle

Cortisol is produced by your adrenal glands according to a natural rhythm: it peaks in the morning when you wake up to give you energy, then gradually decreases throughout the day. In balanced quantities, it is indispensable. It's the chronic dysregulation of this hormone that's becoming a major problem for women's hormonal health.

HPA versus HPG axis: a silent competition

Your stress hormones (HPA axis) and your sex hormones (HPG axis - estrogen, progesterone, LH, FSH) share the same conductor: the hypothalamus. In situations of chronic stress, the HPA axis systematically takes priority.

Direct consequences on your cycle:

• Delay or suppression of ovulation
• Reduced progesterone in the luteal phase
• Irregular, lengthened or shortened cycles
• Worsening of PCOS and endometriosis

Pregnenolone theft: cortisol versus progesterone

Cortisol and progesterone are made from the same precursor: pregnenolone. In the event of prolonged stress, your body "steals" this raw material to produce cortisol first, to the detriment of progesterone.

Low progesterone in the luteal phase leads to :

• Short cycles
• Painful or heavy periods
• Marked PMS (irritability, anxiety, cravings)
• Difficulty conceiving

What cortisol does at each phase of your cycle

Follicular phase

High cortisol slows the rise of estrogen and can delay ovulation. The body in a state of alert postpones reproduction until later.

Ovulation

A cortisol peak at the moment of ovulation can block or reduce the LH peak needed to trigger ovulation.

Luteal phase

The phase most sensitive to stress. Progesterone, already weakened, falls more rapidly. PMS aggravated, inflammation, water retention.

Menstrual phase

Chronically high cortisol amplifies prostaglandin inflammation, making menstruation more painful.

Diet: support your adrenals

Key nutrients

• magnesium: reduces stress response and regulates cortisol - dark chocolate & 70%, pumpkin seeds, almonds, spinach
• Vitamin C: the adrenal glands are very rich in vitamin C and consume a lot of it during stress - bell peppers, kiwi fruit, broccoli, citrus fruit
• Omega-3: reduces inflammation and attenuates the cortisol response - fatty fish, flaxseed, walnuts
• Zinc: supports regulation of the HPA axis - oysters, pumpkin seeds, legumes
• Adaptogens: ashwagandha, rhodiola, tulsi - plants studied to modulate stress response

Limit in case of high cortisol levels

• Excess caffeine (directly stimulates the adrenal glands)
• Refined sugars (glycemic peaks raise cortisol)
• Alcohol (disrupts cortisol's circadian rhythm)
• Ultra-processed foods (pro-inflammatory)

Habits: regulating your cortisol on a daily basis

Respect the circadian rhythm

• Exposure to natural light within 30 minutes of waking up
• Avoid bright screens after 9pm
• Go to bed at regular times

Take care of your sleep

Lack of sleep is one of the most powerful activators of cortisol. A night of 6 hours or less significantly raises cortisol levels the following day.

Exercise without exhausting yourself

Moderate exercise (walking, yoga, swimming) reduces cortisol. Intense exercise without sufficient recovery raises it. In the luteal phase, gentle activity is preferable.

Regulating the nervous system

• Cardiac coherence: 5 seconds in / 5 seconds out, 5 min, 3×/day
• Mindfulness meditation
• Hot bath in the evening
• Time in nature

When to consult?

If you suspect chronically dysregulated cortisol (persistent fatigue on waking, irregular cycles, severe PMS), a 24-hour salivary cortisol test (DUTCH test or salivary cortisol ×4) can be requested from a functional physician or gynecologist.

Scientific sources

• Tsigos C, et al. Stress: Endocrine Physiology and Pathophysiology. Endotext, 2020.
• Whirledge S, Cidlowski JA. Glucocorticoids, stress, and fertility. Minerva Endocrinologica, 2010;35(2):109-125.
• Kalantaridou SN, et al. Stress and the female reproductive system. Journal of Reproductive Immunology, 2004;62(1-2):61-68.
• Leproult R, Van Cauter E. Effect of sleep restriction on testosterone levels. JAMA, 2011;305(21):2173-2174.
• Chandrasekhar K, et al. Efficacy of Ashwagandha root extract. Indian Journal of Psychological Medicine, 2012;34(3):255-262.
• Pickering G, et al. Magnesium Status and Stress: The Vicious Circle Concept Revisited. Nutrients, 2020;12(12):3672.