top of page


Image credit: Minich DM, Henning M, Darley C, Fahoum M, Schuler CB, Frame J. Is Melatonin the "Next Vitamin D"?: A Review of Emerging Science, Clinical Uses, Safety, and Dietary Supplements. Nutrients. 2022;14(19):3934. Published 2022 Sep 22. doi:10.3390/nu14193934.

Adequate darkness at night and brightness in the morning

 The production of melatonin is dependent on the exposure to darkness. Exposure to bright lights (of any color) during the night or evening hours can increase cortisol secretion and, in turn, decrease melatonin production due to their inverse relationship. However, exposure to blue light in the evening has been found to be most disruptive to melatonin production. Conversely, exposure to daytime (early and mid-day) light increased nocturnal melatonin secretion (1,2), and exposure to blue light in the morning has been shown to increase cortisol levels by approximately 130-140% compared to red light (3). Utilizing light exposure may help restore circadian rhythms and cortisol-associated disorders (1–3).




                                       Image credit: Permission for use from Symphony Natural Health, Inc.

Improving adequate darkness exposure

  • Create routines to turn off screens and dim the lights at least an hour before bed.

  • In that hour, do calming activities like reading, puzzles, chamomile tea, or cuddle time with children.

  • Take a warm bath with calming bath salts, chamomile tea, or a few drops of lavender essential oil.

  • Remove nightlights and bright alarm clocks 

  • Hang blackout curtains in the bedroom or use an eye mask

  • Wake consistently every day – to sunlight or a dawn simulator when living in a darker climate

  • Be consistent in sleep routine

  • Get outside – at least one hour of direct sunlight daily supports the natural sleep/wake cycles

Blue Blocking Glasses

The circadian release of melatonin is strongly suppressed by light, particularly blue light. Even light of five to ten lux while sleeping with eyes closed will impact the circadian system (4). Blue-light-blocking glasses can protect from the melatonin-suppressing effects of light (5). When worn during a 60-minute light pulse at 0100 hr, blue-light-blocking glasses resulted in a slight increase in melatonin levels compared to baseline, while melatonin levels decreased significantly by 46% in the control condition (6). After seven nights of wearing blue blockers for two hours before bed, people with insomnia have significantly improved subjective and objective total sleep time, sleep quality, and soundness (7). For people with Delayed Sleep-Wake Phase, wearing blue-light-blocking glasses from 2100 h to bedtime for two weeks resulted in their dim-light melatonin onset occurring 78 min earlier, while sleep onset was significantly earlier by 132 min (8). In healthy adults without sleep or circadian disorders, using blue-light-blocking glasses from 1800 h until bedtime for a week resulted in subjective reports of earlier sleep onset, though objective measures were not improved.


  1. Ensure adequate protein intake, including tryptophan, found in foods like dairy including milk, yogurt, and cheese, eggs, poultry including turkey, chicken, and duck, red meat, pork, tofu, fish including salmon, tuna, cod, snapper, and mahi-mahi, nuts and seeds including chia seeds, flax seeds, cashews, and pistachios.  

  2. Ensure adequate intake of the nutrient cofactors to support the conversation of tryptophan to melatonin. This includes iron, folate, calcium, magnesium, zinc, vitamin C, niacin (vitamin B3),  methylcobalamin (vitamin B12), and pyridoxine hydrochloride (vitamin B6) or pyridoxal phosphate (PLP), the active form of vitamin B6.

  3. Consume foods rich in melatonin as part of a healthy, anti-inflammatory diet. 

Supplemental melatonin

When needed, use the lowest physiological dose of supplemental melatonin to support the desired health outcomes. 


Authors: Deanna Minich, Ph.D., Melanie Henning, ND, Catherine Darley, ND, Mona Fahoum, ND, Corey B. Schuler, DC, James Frame

Reviewer: Content partially peer-reviewed in Nutrients Journal

Last updated: November 14, 2023



1. Nagashima S, Yamashita M, Tojo C, Kondo M, Morita T, Wakamura T. Can tryptophan supplement intake at breakfast enhance melatonin secretion at night? J Physiol Anthropol. 2017;36(1).

2. Hashimoto S, Kohsaka M, Nakamura K, Honma H, Honma S, Honma KI. Midday exposure to bright light changes the circadian organization of plasma melatonin rhythm in humans. Neurosci Lett. 1997;221(2–3).

3. Robertson-Dixon I, Murphy MJ, Crewther SG, Riddell N. The Influence of Light Wavelength on Human HPA Axis Rhythms: A Systematic Review. Life (Basel). 2023 Sep 26;13(10).

4. Tähkämö L, Partonen T, Pesonen AK. Systematic review of light exposure impact on human circadian rhythm. Vol. 36, Chronobiology International. 2019.

5. Hester L, Dang D, Barker CJ, Heath M, Mesiya S, Tienabeso T, et al. Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review. Vol. 38, Chronobiology International. 2021.

6. Bennett S, Alpert M, Kubulins V, Hansler RL. Use of modified spectacles and light bulbs to block blue light at night may prevent postpartum depression. Med Hypotheses. 2009;73(2).

7. Shechter A, Kim EW, St-Onge MP, Westwood AJ. Blocking nocturnal blue light for insomnia: A randomized controlled trial. J Psychiatr Res. 2018;96.

8. Esaki Y, Kitajima T, Ito Y, Koike S, Nakao Y, Tsuchiya A, et al. Wearing blue light-blocking glasses in the evening advances circadian rhythms in the patients with delayed sleep phase disorder: An open-label trial. Chronobiol Int. 2016;33(8).

Cortisol Melatonin.jpg
bottom of page