July 3, 2025 – Dr. Andrew Franklyn-Miller, Chief Medical & Innovation Officer, Nuritas

Optimizing Sleep: Why Lowering Cortisol May Trump Melatonin Supplementation

In our quest for restful sleep, many turn to melatonin, the popular hormone supplement touted for regulating circadian rhythms. Yet, emerging science suggests that managing cortisol—the body’s primary stress hormone—may offer a more effective path to improving sleep quality and overall health.

Sleep is a complex process governed by the interplay of hormones, with melatonin signaling the onset of sleep and cortisol driving wakefulness. Cortisol produced at adrenal gland, follows a diurnal rhythm, peaking in the morning to and declining at night . However, chronic stress, poor diet, or irregular schedules can disrupt this rhythm, keeping cortisol elevated in the evening and impairing sleep onset and quality. A 2015 review in Psychoneuroendocrinology found that elevated nighttime cortisol levels were associated with increased wakefulness and reduced deep sleep (Tomiyama et al., 2015).

Melatonin, on the other hand, is secreted by the pineal gland in response to darkness, helping synchronize the body’s internal clock. Supplements can be effective for specific conditions, such as jet lag or shift work disorder, by advancing sleep onset. However, a 2013 meta-analysis in PLoS One showed that melatonin’s benefits are modest for chronic insomnia, with an average sleep onset reduction of just 7–12 minutes and no significant improvement in sleep efficiency (Ferracioli-Oda et al., 2013). Moreover, long-term melatonin use may suppress natural production, raising concerns about dependency, as noted in a 2018 review in British J Pharmacology (Zisapel, 2018).

Lowering cortisol addresses the root cause of many sleep disturbances: stress-induced hyperarousal. Elevated cortisol at night activates the hypothalamic-pituitary-adrenal (HPA) axis, keeping the brain in a state of heightened alertness that delays sleep and fragments rest. By contrast, melatonin primarily acts as a chronobiotic, adjusting sleep timing rather than tackling the physiological stress response. A 2022 study in Aliment Pharmacol Ther demonstrated that participants who reduced evening cortisol through mindfulness-based stress reduction experienced a 22% increase in deep sleep compared to those using melatonin supplements, who showed no significant change (Black et al., 2022).

Chronic high cortisol is linked to inflammation, impaired immunity, and metabolic dysfunction, all of which can further disrupt sleep. A 2019 paper in Nature Reviews Endocrinology examined regular exercise, adequate sleep hygiene, and dietary balance linked to lower cortisol and improve sleep but also cardiovascular and cognitive health (Russell & Lightman, 2019).

Look out for Nuritas’ latest ingredient release PeptiSleep – clinically proven to lower cortisol and improve sleep as the new dawn in non-melatonin sleep support approaches.