How does stress affect hair?

The essential points to remember.

Stress appears capable of disrupting the hair growth cycle by acting on the nervous system and immunity.
Acute stress situations, such as exam periods, can temporarily slow down hair growth, generally without lasting consequences.
Chronic stress is often accompanied by a prolonged elevation of cortisol measurable in hair, which can disrupt hair balance and make hair more brittle.
Stress may also contribute to premature hair aging and graying, although this connection remains scientifically debated.
The stress management techniques can reduce psychological and physiological stress, with potentially beneficial effects on hair health.
Simple everyday strategies — physical activity, relaxation, leisure pursuits, social support — also contribute to limiting the impact of stress on the body and hair.

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How does stress affect hair?

The stress is now recognized as a factor capable of influencing numerous bodily tissues, including the hair follicle.

Some individuals may notice hair loss or a slowdown in hair growth following an episode of intense psychological or physical stress. These manifestations are explained by the impact of stress on the biological mechanisms that regulate the hair cycle, particularly at the level of follicular stem cells.

Indeed, several studies have shown that stress can slow hair growth by blocking the cell cycle of follicular stem cells. In a mouse model exposed to intense stress — induced either by repeated resiniferatoxin injections or by physical restraint — researchers observed a marked inhibition of regrowth after depilation, in both the telogen and anagen phases. Transcriptomic analysis revealed decreased expression of genes involved in cell proliferation, coupled with activation of the cAMP signaling pathway in Lgr5+ follicular stem cells. This response was accompanied by sympathetic nervous system activation and increased norepinephrine release, which reduced cell proliferation, decreased the expression of cell cycle regulators such as cyclin D1/D2 and CDK4, and increased the proportion of cells in the G0/G1 quiescent phase of the cell cycle.

Beyond these experimental data, some clinical studies have also examined the concrete effects of stress on hair. One study involving 33 medical students assessed the impact of prolonged stress from preparing for a final exam on immunity and hair parameters. Participants were monitored at three distinct time points: before the review period, during exams, and after 12 weeks of recovery. The results show that perceived stress increased significantly during the exams, accompanied by a transient shift in immune balance toward a Th1-type response, as well as measurable changes in the hair growth cycle. However, these alterations remained within physiological limits and disappeared after the rest period, with no lasting differences compared to the control group.

These data suggest that intense stress can temporarily disrupt hair growth via immune mechanisms, while remaining reversible — a reassuring finding for individuals noticing hair loss during periods of intense pressure.

Beyond the transient effects of acute stress, prolonged exposure to chronic stress also appears to affect hair growth. A recent meta-analysis combining 66 independent studies (with over 10,000 participants) examined hair cortisol concentration, a biological marker of cumulative long-term stress exposure. The results show that groups subjected to chronic stress exhibit higher hair cortisol levels than others, which may impair hair growth. Conversely, when stress is in the past, hair cortisol levels no longer differ significantly, suggesting a reversible phenomenon. These data thus reinforce the idea that it is not so much the intensity of a single stress event but the duration of exposure that may have a lasting impact on hair health.

+ 22%

hair cortisol levels in groups subjected to chronic stress (a meta-analysis of 66 studies, involving over 10,000 participants).

+ 43%

hair cortisol in groups exposed to chronic stress that remained present at the time of assessment (meta-analysis including 66 studies, involving over 10,000 participants).

Moreover, stress could also accelerate the graying of hair.

It should be recalled that hair color depends on the activity of the melanocytes located in the hair follicle, which are responsible for melanin production. During episodes of stress, the release of neurotransmitters by the nervous system can promote the establishment of an oxidative stress characterized by the accumulation of free radicals capable of damaging melanocyte DNA to the point of impairing their function. This type of oxidative damage is more broadly implicated in the cellular aging of skin and hair. However, while some empirical data suggest a link between stress, oxidative stress, and the onset of gray hair, direct scientific evidence remains limited to date, indicating that other factors—genetic, hormonal, or environmental—also contribute to the hair depigmentation process.

How can the effects of stress on hair be mitigated?

When addressing the potential effects of stress on hair, treatment primarily relies on strategies aimed at reducing psychological burden and its physiological consequences.

Interventions such as mindfulness-based stress reduction, cognitive-behavioral therapy, or hypnotherapy have demonstrated their ability to improve mental health, reduce anxiety, and, in some cases of hair loss, promote hair regrowth. More broadly, structured stress management programs can lead to a decrease in cortisol levels measured in hair, thereby suggesting a potential benefit for balancing the hair growth cycle.

A controlled clinical study involving 78 pregnant women specifically evaluated the effectiveness of a cognitive-behavioral stress management therapy on hair cortisol levels. Participants were assigned either to a control group or to a group undergoing eight weekly CBT sessions. After the intervention, only the women in the CBT group showed a concurrent reduction in both hair cortisol and perceived stress, including pregnancy-related stress.

Scores avant et après l’intervention dans les principales mesures de stress. — Pre- and post-intervention scores on the primary stress measures.
Source: PERALTA-RAMIREZ R. I. & al. Effects of cognitive-behavioural therapy for stress management on stress and hair cortisol levels in pregnant women: A randomised controlled trial. Journal of Psychosomatic Research (2020).

Learning to manage stress thus appears to be an effective means of preserving psychological, physical, and even hair health.

Note : It is not always necessary to rely on complex approaches to better manage daily stress. Taking a step back in difficult situations, maintaining regular physical activity, practicing meditation or breathing exercises, preserving leisure time, and connecting with one’s social circle are all simple strategies that help limit stress. However, when anxiety becomes overwhelming or persistent, psychological support can be beneficial for restoring better balance in everyday life.