Stress is not just a psychological feeling, it's a rapid, whole-body hormonal event. When we perceive a threat - whether it’s physical or psychological - our brain switches on the what’s referred to as the hypothalamic-pituitary-adrenal (HPA) axis. Within minutes, stress hormones rise and our physiology shifts to meet the demand: we mobilise blood sugar, our heart rate increases, and our priorities move from long-term repair to short-term survival. Importantly, our body can't distinguish between running from danger and responding to emails or deadlines; both trigger the same survival physiology when the perceived stress is high. Unlike acute stress, which resolves quickly, modern stressors are often chronic, low-grade, and lead to a persistent activation of this system. Over time, this sustained hormonal signal can disrupt metabolic, reproductive, immune, and sleep regulation, which is why we can’t balance our sex hormones without first looking at stress. Let’s take a closer look at how stress cascades throughout the body.
Cortisol 101
Cortisol is the primary stress hormone. In the short term, it raises blood sugar to fuel the brain and muscles, dials down inflammation, and heightens alertness. But when cortisol stays elevated, it takes a toll on our physiology and can lead to fatigue, disrupted sleep, worse immune function, more central fat storage, and poorer glucose regulation. Cortisol also influences appetite centres in the brain and increases our preference for sugar and fat-rich foods, which helps explain why stress eating is biologically driven rather than purely behavioural. (1)
Stress + Blood Sugar
One of cortisol’s jobs is to ensure that we have energy available, and as such, it stimulates the release of sugar from stored glycogen. It also reduces insulin sensitivity to ensure that we have fuel available during a threat. When stress is chronic, this mechanism can lead to persistently elevated blood sugar and compensatory insulin resistance. Ironically, this rebound can make things worse. After a spike, glucose can drop quickly, and that dip can trigger another cortisol release. Because of this, we end up in a self-reinforcing loop: unstable blood sugar, energy crashes, then another wave of stress activation. Research shows that psychological stress alone can impair how well we control blood sugar, even without changes in diet or activity. (2) That means we can eat and train exactly as we always do and still see our blood sugar become less stable, driven purely by stress.
Stress + Sex Hormones
This is where stress can wreak havoc. When the stress response stays chronically activated, reproduction is one of the first systems we suppress, simply is not deemed urgent for survival. A persistently “on” stress signal impacts the hypothalamic-pituitary-gonadal (HPG) axis, and can make ovulation less reliable, lower progesterone, and impact the regularity of our cycles. Over time, this may contribute to a worsening of PMS, heavy or painful periods, and changes in fertility. In both sexes, chronic stress is associated with reduced testosterone, which can manifest as low libido, fatigue, reduced muscle mass, and diminished motivation. These effects, however, reflect our bodies efforts to conserve energy and ensure it’s safe before we reproduce rather than a primary reproductive disorder. (3,4)
Stress + Digestive Hormones
Digestion is another function that is deemed non-essential during times of stress, and as such, is deprioritised when stress is high. Blood flow is redirected away from the gastrointestinal tract toward muscles and the brain, which reduces stomach acid secretion, pancreatic enzyme output, and coordinated gut motility – all of which will suppress digestion. Stress also changes communication along the gut-brain axis, which impacts hormones and neuropeptides involved in appetite, satiety, and inflammation. In practice, we often see this as bloating, reflux, changes in bowel habits, or poorer nutrient absorption, especially in those of us with functional gut issues. (5)
Stress + Sleep
And finally, we’ve probably all felt the impact that stress has on our sleep. Cortisol follows a circadian rhythm – it's naturally highest in the early morning to promote wakefulness, and lowest at night to allow sleep and repair. Chronic stress can flatten or shift this rhythm; elevated evening cortisol can keep us wired, despite being tired, and suppresses melatonin, the hormone that regulates sleep timing and quality. The result is often difficulty falling asleep, night waking, and non-restorative sleep - which in turn further heightens stress reactivity the following day. (7)
The Solution
Because stress hormones plug into every major endocrine pathway, the symptoms we feel can look completely unrelated; fatigue, digestive issues, cycle changes, poor sleep, cravings, yet share a common physiological driver. And, because these symptoms will be heightened throughout different phases of the menstrual cycle, we’re often quick to blame our sex hormones. So, if we want more stable hormones, we need to shift the focus away from chasing symptoms and towards building stress resilience: adequate nutrition, better sleep, real recovery, and crucially, nervous system regulation. The goal is not just to reduce stressors – because let’s face it, this isn’t always possible – but instead, it’s to increase our capacity to recover from them.
Our favourite tools for stress:
The 10 minute wind down before bed (choose one and try it everyday)
- Physiological sighs (slow inhale, top-up inhale, long exhale, repeat)
- Calming breath-work (use a recording if needed)
- Extended exhale breathing (inhale 4, exhale 6–8)
- Guided mindfulness (use an app)
- Legs up the wall
- Slow walk with nasal breathing
- Mobility on the floor
- Foam rolling
- Yoga nidra (use a recording)
- Hot shower + quiet room after (if that’s your only option)
Supplements:
- Enhanced Nootropics, for those dealing with an always on, hectic lifestyle. Includes ashwagandha, b complex, magnesium and 5 HTP
- Advanced Multi-Nutrient, for full spectrum vitamin, mineral, and herbal support with over 40 active nutrients for whole body resilience.
- Essential Magnesium, if you want to start with a simple evening ritual.
- Cellular Hydration, to get you through stressful days with energy and targeted nervous system support.
- Digest + Debloat, powerful bitters to stimulate digestion for when you know that stress is seriously slowing you down.
References
Kaur J, Gandhi J, Sharma S. Physiology, Cortisol. [Updated 2025 Dec 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538239/
Khani S, Tayek JA. Cortisol increases gluconeogenesis in humans: its role in the metabolic syndrome. Clin Sci (Lond). 2001 Dec;101(6):739-47. doi: 10.1042/cs1010739. PMID: 11724664.
Son YL, Ubuka T, Tsutsui K. Regulation of stress response on the hypothalamic-pituitary-gonadal axis via gonadotropin-inhibitory hormone. Front Neuroendocrinol. 2022 Jan;64:100953. doi: 10.1016/j.yfrne.2021.100953. Epub 2021 Oct 29. PMID: 34757094.
Mbiydzenyuy NE, Qulu LA. Stress, hypothalamic-pituitary-adrenal axis, hypothalamic-pituitary-gonadal axis, and aggression. Metab Brain Dis. 2024 Dec;39(8):1613-1636. doi: 10.1007/s11011-024-01393-w. Epub 2024 Jul 31. PMID: 39083184; PMCID: PMC11535056.
Konturek PC, Brzozowski T, Konturek SJ. Stress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options. J Physiol Pharmacol. 2011 Dec;62(6):591-9. PMID: 22314561.
Kuckuck S, van der Valk ES, Scheurink AJW, et al. Glucocorticoids, stress and eating: The mediating role of appetite-regulating hormones. Obesity Reviews. 2023; 24(3):e13539. doi:10.1111/obr.13539
O'Byrne NA, Yuen F, Butt WZ, Liu PY. Sleep and Circadian Regulation of Cortisol: A Short Review. Curr Opin Endocr Metab Res. 2021 Jun;18:178-186. doi: 10.1016/j.coemr.2021.03.011. Epub 2021 May 5. PMID: 35128146; PMCID: PMC8813037.
