Functional Endocrinology: Cortisol and Melatonin Circadian Rhythm


Do you feel:

  • You cannot stay asleep at night?
  • You have a slow start in the morning?
  • Afternoon fatigue?
  • Waking up tired even after getting six or more hours of sleep?
  • Under a high amount of stress?

If you are experiencing any of these situations, then it might be due to your melatonin and cortisol levels affecting your body and circadian rhythm.

Across the world, millions of people have trouble sleeping. In the United States, there are roughly about 50-70 million people who have a poor quality of sleep. When a person has slept for less than eight hours, they become tired, and many problems can come to them, especially if their lives are hectic. With a hectic lifestyle and poor sleep, it can cause the body to have low energy to get any task done, the cortisol stress hormone will be raised, and diseases like high blood pressure and diabetes can cause problems that can be chronic if it is not treated.

In functional endocrinology, melatonin and cortisol are hormones that the body produces naturally. The cortisol hormone or the stress hormone helps the body be in a state of “fight or flight” mode, which can be a good thing for anyone who is doing a project or going for a job interview. Although when cortisol hormone levels are high, it can lead the body to have complications like inflammation, chronic oxidative stress, and high blood pressure.

The Melatonin Circadian Rhythm

With the melatonin hormone, this hormone tells the body when it is time to sleep. Sometimes though, people do have a hard time sleeping, and taking melatonin supplements can actually relax the body and thus making the person fall asleep. Since the pineal gland produces melatonin from the brain, it can also be found in the eyes, the bone marrow, and the gut to relax the body and making the person fall asleep naturally. Some studies show that the circadian rhythm of the pineal gland that is producing melatonin. By doing this, the research shows that the administration of melatonin can:

  • One: induce sleep on individuals who have trouble falling asleep.
  • Two: inhibits the body to wake up naturally from the circadian pacemaker.
  • Three: shift the circadian biological clocks to increase sleep intake when a person is trying to sleep at an earlier time to get the full eight-hour benefits of sleep.

When a person is working at a 9 to 5 job, they are rising with their bodies and relaxing their bodies after a hard day at work. Studies found out that the melatonin and cortisol hormones help regulate the 24-hour pattern of the body’s function and responses tremendously. With the body’s hormone production cycle, it can be disturbed if the person is staying awake late at night or sleeping during the day. When this happens, the person can get disruptive disorders like mood swings, dizziness, be irritable and depressed, and have metabolic disorders. Not only that, but the body’s immune system and its endocrine system can also be damaged as well, causing the body to be a host to infections and diseases.

There have been more studies on the circadian rhythms in the body, as the studies show how people who work in the night shift have been associated with a vast number of adverse health problems that attack the cardiovascular and gastrointestinal system as well as disturbing the metabolic system. Anyone who has worked the night shift has to change their sleep schedule and adapt to the rapid reorientation in their sleep/wake schedule to go to work and do their job. Since everyone is working at a shift schedule, it can be stressful and can affect a worker’s body performance as well as affecting melatonin and cortisol secretion.

Ways To Support Cortisol and Melatonin

Surprisingly though, there are ways to lower cortisol levels and make sure that melatonin levels are working correctly for the body to function. For cortisol levels to be lowered, a person should do meditative practices, find an enjoyable hobby, and, most importantly, try deep breathing exercises to relax the body from unwanted stress. With deep breathing exercises, it can help the body to release any tension that a person is holding, and the muscles in the body began to relax, and the blood starts to flow. With the melatonin levels, they work together with the body’s circadian rhythm and make sure the body knows when it is time to wake up, sleep and eat. The melatonin hormone can also help regulate the body’s temperature, blood pressure, and hormone levels to make sure it is functioning correctly. When there are high levels of these systems, it can cause the body to develop chronic illnesses and harm the body in the process.

Research shows that melatonin hormones can bind to neurological receptors in the body, thus promoting relaxation. Since melatonin binds to neurological receptors, it can also reduce nerve activity and dopamine levels to make the eyes heavy, thus making the person fall asleep.


With the body being able to naturally produce melatonin and cortisol levels to make sure that the body does not get overly stressed throughout the entire day. Since melatonin is partnered with the body’s circadian rhythm, the body knows when to stay up and fall asleep. Since everyone has a hectic schedule, it is essential to take time and relax and get on a healthy sleep schedule so the body can be healthy and functioning. Some products are here to make sure that the endocrine system is functioning properly and supporting the adrenal glands and sugar metabolism.

The scope of our information is limited to chiropractic, musculoskeletal, and nervous health issues or functional medicine articles, topics, and discussions. We use functional health protocols to treat injuries or disorders of the musculoskeletal system. Our office has made a reasonable attempt to provide supportive citations and has identified the relevant research study or studies supporting our posts. We also make copies of supporting research studies available to the board and or the public upon request. To further discuss the subject matter above, please feel free to ask Dr. Alex Jimenez or contact us at 915-850-0900.


Cajochen, C, et al. “Role of Melatonin in the Regulation of Human Circadian Rhythms and Sleep.” Journal of Neuroendocrinology, U.S. National Library of Medicine, Apr. 2003,

James, Francine O, et al. “Circadian Rhythms of Melatonin, Cortisol, and Clock Gene Expression during Simulated Night Shift Work.” Sleep, Associated Professional Sleep Societies, LLC, Nov. 2007,

Monteleone, P, et al. “Temporal Relationship between Melatonin and Cortisol Responses to Nighttime Physical Stress in Humans.” Psychoneuroendocrinology, U.S. National Library of Medicine, 1992,

Raman, Ryan. “How Melatonin Can Help You Sleep and Feel Better.” Healthline, Healthline Media, 3 Sept. 2017,

Zamanian, Zahra, et al. “Outline of Changes in Cortisol and Melatonin Circadian Rhythms in the Security Guards of Shiraz University of Medical Sciences.” International Journal of Preventive Medicine, Medknow Publications & Media Pvt Ltd, July 2013,

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The information herein on "Functional Endocrinology: Cortisol and Melatonin Circadian Rhythm" is not intended to replace a one-on-one relationship with a qualified health care professional or licensed physician and is not medical advice. We encourage you to make healthcare decisions based on your research and partnership with a qualified healthcare professional.

Blog Information & Scope Discussions

Our information scope is limited to Chiropractic, musculoskeletal, acupuncture, physical medicines, wellness, contributing etiological viscerosomatic disturbances within clinical presentations, associated somatovisceral reflex clinical dynamics, subluxation complexes, sensitive health issues, and/or functional medicine articles, topics, and discussions.

We provide and present clinical collaboration with specialists from various disciplines. Each specialist is governed by their professional scope of practice and their jurisdiction of licensure. We use functional health & wellness protocols to treat and support care for the injuries or disorders of the musculoskeletal system.

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Our office has reasonably attempted to provide supportive citations and has identified the relevant research studies supporting our posts. We provide copies of supporting research studies available to regulatory boards and the public upon request.

We understand that we cover matters that require an additional explanation of how it may assist in a particular care plan or treatment protocol; therefore, to further discuss the subject matter above, please feel free to ask Dr. Alex Jimenez, DC, or contact us at 915-850-0900.

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Dr. Alex Jimenez DC, MSACP, RN*, CCST, IFMCP*, CIFM*, ATN*


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