Stress and the Skin: The Hidden Role of Cortisol

It’s no secret that stress leads to skin flare-ups. From acne breakouts to inflamed eczema, stress remains a key trigger for diminished skin health. Whilst stress is the psychological component in this brain-to-skin interaction, when it comes to biological processes, the real culprit here is the hormone cortisol.

This article will explore the science behind stress and the skin from the lens of a neuropsychology graduate. Cortisol’s role in the stress response will be discussed as well as the biological mechanisms by which it impacts the skin. Ultimately, the science highlights that looking after your mind is a crucial piece of the puzzle when it comes to managing your skin health.

Secreted by the adrenal glands in the kidneys, cortisol is considered the body’s primary stress hormone (Chen and Lyga, 2014). In normal levels, cortisol is in fact a good thing; this glucocorticoid hormone plays a crucial role in various bodily functions including sleep-wake cycles, metabolism and blood pressure.

Cortisol levels follow a natural daily rhythm, peaking in the morning to help us wake up and gradually declining throughout the day. The hormone is also extremely useful when responding to perceived threats and initiating the body’s Fight or Flight response. However, the issue arises when cortisol levels become too high – this is known as hypercortisolism (or hypercortisolaemia) and is often indicative of increased stress (Dedovic et al, 2009).

To understand exactly how feeling stressed results in cortisol production, we turn to the hypothalamic-pituitary-adrenal axis (HPA axis). This neuroendocrine mechanism triggers a hormone cascade from the brain to the kidneys, ending with the production of cortisol.

Here’s the breakdown:

1)     A small region at the base of the brain called the hypothalamus produces corticotropin-releasing hormone (CRH) in response to stressful situations.

2)     CRH then stimulates the pituitary gland just below the hypothalamus. The pituitary gland is considered the “master gland” as it produces hormones that are crucial for a range of bodily functions. In response to the CRH it produces a hormone called adrenocorticotropic hormone (ACTH).

3)     ACTH then travels via the bloodstream to the kidneys, where the adrenal glands are stimulated to produce cortisol.

Hypercortisolism is used as a marker of stress as it reflects the function of this HPA axis (Qin et al, 2015).

The effects of hypercortisolism often manifest physically in the skin. The skin and brain communicate through a network called the skin-brain axis (Zhang et al., 2024). When it comes to stress specifically, effects on the skin are exerted mainly through the HPA axis and cortisol (Chen and Lyga, 2014).

Cortisol causes an increase in sebaceous gland activity. These glands secrete sebum (or serum), an oily substance that lubricates the skin. If cortisol levels are high, increased sebum secretion occurs which can result in skin appearing oily. This also has implications for existing acne; increased sebum can exacerbate acne lesions, with research suggesting an association between cortisol levels and acne severity (Borzyszkowska et al., 2022).

Cortisol also impairs the skin barrier function (Kim et al., 2023). The skin barrier is the outmost layer of the skin, which acts as a crucial defence from environmental irritants such as pathogens, chemicals and UV radiation. Therefore, impaired functioning of the skin barrier can severely compromise immune responses and the body’s natural defence mechanisms. For instance, elevated cortisol has been linked to an increased risk of skin infections (Maarouf et al., 2019).

Wound healing also appears to be compromised by cortisol (Pujos et al., 2014) which can have implications for eczema healing and even acne scars. Diminished skin barrier integrity can additionally be visible in the form of fine scale irregularities on the surface of the skin, including changes to skin texture and the appearance of fine lines (Pujos et al., 2014).

The skin can also become inflamed due to cortisol and even CRH. These hormones impair the keratinocyte epidermal barrier and trigger the secretion of pro-inflammatory cytokines (Zhang et al., 2024). This can lead to redness, swelling and sensitivity in the skin, meaning that conditions such as eczema and psoriasis are more likely to flare up.

More generally, heightened inflammation can have significant negative consequences to overall health and well-being, with inflammation being associated with weakened immune responses, cardiovascular problems and depression (Amasi-Hartoonian et al., 2022).

Despite being psychological, stress leads to real biological consequences in our bodies. We’ve seen that excess cortisol due to stress can have a substantial effect on overall skin health and pre-existing skin conditions. The evidence being a stark reminder of the brain-skin link and highlighting the importance of mental health when it comes to skin health.

Given the effects of cortisol, products with anti-inflammatory and barrier-strengthening ingredients, like niacinamide or ceramides, are often recommended for stressed skin. However, whilst cleansers, serums and moisturisers remain an essential part of any skincare routine, another step you can take to prioritise your skin, is to prioritise your mind.

Consider incorporating stress-reducing practices into your lifestyle; mind-body therapies like meditation, yoga or guided imagery, alongside lifestyle habits such as maintaining a balanced diet and regular sleep, have all been shown to lower cortisol and reduce overall stress.

Remember, prioritising mental wellbeing not only helps to lower stress and promote overall wellbeing but also supports healthier, clearer skin. After all, when you glow on the inside, you glow on the outside.

Amasi-Hartoonian, N., Sforzini, L., Cattaneo, A., & Pariante, C. M. (2022). Cause or consequence? Understanding the role of cortisol in the increased inflammation observed in depression. Current opinion in endocrine and metabolic research, 24, e100356. https://doi.org/10.1016/j.coemr.2022.100356

Borzyszkowska, D., Niedzielska, M., Kozłowski, M., Brodowska, A., Przepiera, A., Malczyk-Matysiak, K., Cymbaluk-Płoska, A., & Sowińska-Przepiera, E. (2022). Evaluation of Hormonal Factors in Acne Vulgaris and the Course of Acne Vulgaris Treatment with Contraceptive-Based Therapies in Young Adult Women. Cells, 11(24), 4078. https://doi.org/10.3390/cells11244078

Chen, Y., & Lyga, J. (2014). Brain-skin connection: stress, inflammation and skin aging. Inflammation & allergy drug targets, 13(3), 177–190. https://doi.org/10.2174/1871528113666140522104422

Dedovic, K., Duchesne, A., Andrews, J., Engert, V., & Pruessner, J. C. (2009). The brain and the stress axis: The neural correlates of cortisol regulation in response to stress. NeuroImage, 47(3), 864–871. https://doi.org/10.1016/j.neuroimage.2009.05.074

Kim, J., Byung Eui Kim, Evgeny Berdyshev, Bronova, I., Bin, L., Bae, J., Kim, S., Kim, H.-Y., Un Ha Lee, Myoung Shin Kim, Kim, H.-M., Jin Young Lee, Hall, C. F., Hui, J., Chang, Y., Anna Sofia Bronoff, Hwang, D., Hae Young Lee, Goleva, E., & Ahn, K. (2023). Staphylococcus aureus causes aberrant epidermal lipid composition and skin barrier dysfunction. Allergy, 78(5), 1292–1306. https://doi.org/10.1111/all.15640

Maarouf, M., Maarouf, C. L., Yosipovitch, G., & Shi, V. Y. (2019). The impact of stress on epidermal barrier function: an evidence‐based review. British Journal of Dermatology, 181(6), 1129-1137. https://doi.org/10.1111/bjd.17605

Pujos, M., Chamayou‐Robert, C., Parat, M., Bonnet, M., Couret, S., Robiolo, A., & Doucet, O. (2024). Impact of chronic moderate psychological stress on skin aging: exploratory clinical study and cellular functioning. Journal of Cosmetic Dermatology, 24(1), e16634. https://doi.org/10.1111/jocd.16634 

Qin, D., Rizak, J., Chu, X., Li, Z., Yang, S., Lü, L., Yang, L., Yang, Q., Yang, B., Pan, L., Yin, Y., Chen, L., Feng, X., & Hu, X. (2015). A spontaneous depressive pattern in adult female rhesus macaques. Scientific reports, 5, 11267. https://doi.org/10.1038/srep11267

Zhang, H., Wang, M., Zhao, X., Wang, Y., Chen, X., & Su, J. (2024). Role of stress in skin diseases: A neuroendocrine-immune interaction view. Brain, Behavior, and Immunity, 116, 286–302. https://doi.org/10.1016/j.bbi.2023.12.005