Sauna for endocrine system support

Sauna Therapy, Cortisol & Hormonal Balance

Hormones quietly shape how we feel, think, sleep, recover, and cope with stress. When they are balanced, the body feels resilient and steady. When they are dysregulated (often due to chronic stress, poor sleep, or inflammation) mental, emotional, and physical health can begin to unravel.

Among the growing body of research into non-pharmaceutical wellness interventions, sauna therapy is increasingly recognised for its influence on the endocrine system, particularly stress hormones such as cortisol.

This article explores how sauna therapy affects hormonal health, why cortisol balance matters, and how regular heat exposure may support long-term resilience rather than short-term stimulation.

Understanding Cortisol: The Stress Hormone

Cortisol is often misunderstood. It is not a “bad” hormone. It is essential for survival.

Produced by the adrenal glands, cortisol plays a key role in regulating blood sugar, modulating inflammation, supporting energy production, maintaining blood pressure, and orchestrating the body’s stress response.

Problems arise when cortisol remains elevated for prolonged periods. Unfortunately, this is an all-too-common outcome of our modern lifestyles characterised by constant stimulation, poor sleep, and psychological stress.

Chronic cortisol elevation has been associated with anxiety and low mood, sleep disruption, insulin resistance, abdominal fat accumulation, and impaired immune function.

Balancing cortisol is not about suppressing stress entirely. It is about restoring a natural rhythm to how the body responds to it.

Sauna Therapy as Hormetic Stress

Sauna therapy works through hormesis, which is a biological principle where a low-dose stressor triggers beneficial long-term adaptive responses.

During a sauna session, your core body temperature rises, heart rate increases, and cortisol, adrenaline and noradrenaline temporarily increase. Don’t worry, this acute stress response is short-lived, and with repeated exposure, the body adapts by learning how to respond more efficiently.

A review published in Mayo Clinic Proceedings found that regular sauna bathing improves autonomic nervous system balance and reduces chronic stress markers, including baseline cortisol levels, over time (Hussain & Cohen, 2018).

Cortisol Adaptation: Short-Term Rise, Long-Term Regulation

One of the most important distinctions in understanding sauna therapy is the difference between acute hormonal response and chronic hormonal adaptation.

This improved regulation manifests as lower resting cortisol, reduced exaggerated stress responses, and a faster return to baseline after stress.

These adaptations mirror those seen with regular physical exercise which is another hormetic stressor known to improve endocrine health!

Insulin Sensitivity & The Metabolic System

A study published in JAMA Internal Medicine found that frequent sauna bathing was associated with improved metabolic health outcomes (Laukkanen et al., 2015).

Cortisol closely interacts with insulin, the hormone responsible for blood sugar regulation. Chronically elevated cortisol can impair insulin sensitivity, which directly impacts the metabolic system. However, short, sharp burst of cortisol over time leads to adaptation and enhanced insulin sensitivity.

For individuals experiencing stress-related fatigue, brain fog, or energy crashes, supporting cortisol– insulin balance is foundational.

The Growth Hormone

Heat exposure stimulates the release of human growth hormone (HGH) which is a key hormone involved in tissue repair, metabolism, and nervous system health. A controlled study published in The Journal of Clinical Endocrinology & Metabolism demonstrated that repeated sauna exposure significantly increased growth hormone secretion during sessions (KukkonenHarjula et al., 1989).

HGH works at a cellular level, promoting cell growth and repair, and reducing inflammation. While HGH is often discussed in the context of physical recovery, it also plays a role in brain health, cognitive function, and emotional regulation.

Cortisol, Sleep & Circadian Rhythm

Cortisol follows a natural daily rhythm: high in the morning to promote alertness, and low in the evening allowing melatonin to rise. Chronic stress disrupts this rhythm resulting in continuous cortisol elevation throughout the day and into the night, difficulty falling asleep, night-time awakenings, and subsequent morning fatigue!

Sauna therapy supports circadian alignment by helping the body better adapt to cortisol. Entering and leaving the sauna also mimics the natural drop in body temperature that occurs in the evening which is a natural biological signal for sleep initiation. Research published in Sleep Medicine Reviews shows that passive body heating before bedtime can reduce sleep onset latency (how long you take to fall asleep) and improve sleep depth and quality (Haghayegh et al., 2019).

At Sôlt Haus, evening sauna sessions can be paired with red light therapy which further supports circadian signaling and melatonin production. A study in Journal of Athletic Training found that red light exposure improved sleep quality and melatonin levels in athletes who arguably experience higher levels of physiological stress (Zhao et al., 2012).

The Role of Halotherapy in Hormonal Regulation

Breathing patterns directly influence the parasympathetic nervous system and hormonal responses. It’s why breathwork is a growing in popularity as a wellness practice.

Halotherapy (breathing salt-air) encourages slower, deeper breathing and supports respiratory efficiency. Clinical research published in International Journal of Chronic Obstructive Pulmonary Disease indicates that dry salt aerosol therapy can improve airway function and reduce inflammation (Cervenka & Zilber, 1995).

When halotherapy is used a sauna setting, particularly the dry heat of infrared, by slowing and deepening our breath pattern, it better supports the parasympathetic nervous system and enhances hormonal functioning. This is why we integrate salt into our saunas at Sôlt Haus!

References

• Hussain, J., & Cohen, M. (2018). Clinical effects of regular dry sauna bathing: A systematic review. Mayo Clinic Proceedings.

• Jezová, D., et al. (1994). Neuroendocrine responses to heat stress. Psychoneuroendocrinology.

• Laukkanen, T., et al. (2015). Sauna bathing and cardiovascular health. JAMA Internal Medicine.

• Kukkonen-Harjula, K., et al. (1989). Effect of sauna bathing on growth hormone secretion. Journal of Clinical Endocrinology & Metabolism.

• Haghayegh, S., et al. (2019). Passive body heating and sleep: A systematic review. Sleep Medicine Reviews.

•        Zhao, J., et al. (2012). Effect of red light therapy on sleep and melatonin. Journal of Athletic Training.

• Chervinskaya, A. V., & Zilber, N. A. (1995). Halotherapy for respiratory diseases. International Journal of Chronic Obstructive Pulmonary Disease.