Sanesco Blog

Melatonin and the Immune System: The Sleeper Antioxidant


Melatonin is commonly known for its role in sleep. However, the relationship between melatonin and the immune system is just as important for our health.

The Benefits of Melatonin

Few things in life are as important as a good night’s sleep. Healthy sleep cycles contribute to the proper function of numerous body systems including the nervous, cardiovascular, endocrine, gastrointestinal, and of particular significance as of late, the immune system.1 However, according to Wayne Giles, M.D., from the Centers’ for Disease Control and Prevention (CDC), more than 33% of American adults get less than seven hours.2

When faced with sleep irregularities, many people look to supplementation for support. Melatonin, often referred to as the body’s “sleep hormone,” plays a pivotal role in circadian rhythm regulation and the sleep-wake cycle. Because of this, it often serves as the first choice for many people who have trouble falling or staying asleep.* Surprisingly, melatonin also functions as a potent free radical scavenger and an immune system modulator, highlighting a possible link between a restful night’s sleep and immune system health.*

Melatonin and the Immune System

It turns out that while we sleep, T-cells of the immune system “learn” defenses against foreign agents in a process called adaptive immunity. Pro-inflammatory molecules such as IL-2, IL-6, and IL-12 drive this type of response, and melatonin stimulates the production of all three.*3 Therefore, restful sleep is critical as rising melatonin levels enhance the immune system’s ability to adapt and create new responses.*

Pro-inflammatory cytokines can also contribute to oxidative stress. Melatonin’s unique chemical structure makes it a potent free radical scavenger, enabling one molecule to effectively neutralize up to four different radical oxygen or nitrogen species.*4 In this way, melatonin acts , neutralizing harmful effects caused by the release of free radical ions.*5 In fact, melatonin is such an excellent antioxidant that it has been retained in virtually every organism from prehistoric prokaryotes to human beings5, proving that it is simply too effective not to keep around.*

Additionally, melatonin helps to maintain balanced activity within the immune system. Melatonin is thought to help stimulate the immune system when activity is low or suppressed as well as bring the immune system under control during acute inflammatory responses.*5 It seems, melatonin helps the immune system to maintain healthy levels of activity.

Melatonin Production Outside the CNS

Interestingly, melatonin production also takes place outside of the central nervous system. Key immune structures like the spleen, liver, and bone marrow synthesize melatonin. Even some cells of the immune system such as macrophages, mast cells, and natural killer cells can produce melatonin in a paracrine manner.6,7

In fact, the location of melatonin production depends on what is currently taking place inside the body. In other words, if there is an acute immune response taking place, melatonin production shifts from the brain to the site of the injury where it functions as an antioxidant and anti-inflammatory molecule.*8,9,10 Indeed, melatonin inhibits production of certain powerful inflammatory markers such as TNF-α, IL-1β, and INF-γ.*5,9,10 It is no wonder that this incredible molecule continues to emerge as a key player in a healthy immune response as well as a good night’s sleep.

Learn how you can support healthy melatonin levels.

Clinical Contributor

Peter Tracy, Clinical Support Representative

Peter graduated from the University of Central Florida with a double major in Biotechnology and Biomedical Sciences in 2015. He began his career with the Department of Neurosurgery at the Mayo Clinic of Jacksonville, Florida in 2016. Peter joined the Clinical Support Team of Sanesco in November 2020. His interests include functional integrative medicine, exploring the great outdoors, sports, and spending time with his wife, Amina, and their cattle dog, Smokey.


  1. Banks S, et al. J Clin Sleep Med. 2007;3(5):519-528.
  2. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention Online. 2016.
  3. Srinivasan V, et al. Immunity and Ageing. 2005;2:17.,12%20is%20stimulated%20by%20melatonin.
  4. Tan DX, et al. Current Topics in Medicinal Chemistry. 2002;2(2):181-197.
  5. Carrillo-Vico A, et al. International Journal of Molecular Sciences. 2013;14(4):8638-8683.
  6. Emet M, et al. Eurasian Journal of Medicine. 2016;48(2):135-141.
  7. Carrillo-Vico A, et al. FASEB J. 2004;18(3):537-539.
  8. Markus RP, et al. Neuroimmunomodulation. 2007;14(3-4):126-133.
  9. Markus RP, et al. International Journal of Molecular Sciences. 2013;14(6):10979-10997.
  10. Markus RP, et al. British Journal of Pharmacology. 2018;175(16):3239-3250.
  11. Pontes GN, et al. Journal of Pineal Research. 2007;43(4):365-371.
  12. Tarocco, A., et al.Cell Death and Disease 2019;10. 317.,%2C71%2C72%2C73.
  13. Esposito E, et al. Current Neuropharmacology. 2010;8(3):228-242.
  14. Tan DX, et al. Molecules. 2015;20(10):18886-18906.,is%20referred%20as%20its%20cascade.
  15. Hardeland, R. Cellular and Molecular Life Sciences.2017;74. 3883–3896.
  16. Mayo Foundation for Medical Education and Research. Mayo Clinic Online. 2018.,blood%20vessel%20(cardiovascular)%20disease





Sharon Norling, MD, MBA

Sharon Norling, MD, MBA

Dr. Sharon Norling is a nationally known and highly respected medical doctor specializing in integrative medicine and practicing advanced functional medicine in Hendersonville, NC. Dr. Norling graduated from Case Western Reserve School of Medicine and has trained at USC and UCLA. She received her MBA from St. Thomas University.

Dr. Norling’s expertise is based on her years of clinical experiences, former Assistant Professor at the University of Minnesota Medical School, and her research. She is national board-certified in OB/GYN, Integrative Medicine and Medical Acupuncture. Dr. Norling combines a credible and responsible academic knowledge with years of experience and a caring nature.

Recognized for her expertise, she has testified before the White House Commission on Complementary Alternative Medicine Policy. She has served in multiple leadership roles as Medical Director and senior management in two large healthcare organizations.During her years in health care she has been nurse, medical doctor, hospital administrator, advocate and a dismissed and misdiagnosed patient.

Her passion is finding the root cause of illnesses instead of just using a pharmaceutical drug to treat the tip of the iceberg. Hormonal and neurotransmitter balancing is one of her specialties.

Dr. Norling is an international speaker and the author of Your Doctor is Wrong. As a presenter, she is engaging, articulate, humorous, and insightful, making learning a dynamic professional and personal growth experience. Whether you have heard her on the radio, seen her on TV or sharing the stage with celebrities, Dr. Norling is the expert.

Dr. Norling is a medical authority, a visionary and an extraordinary leader who provides real solutions for patients who have been dismissed or misdiagnosed.

Disclaimer: The information provided is only intended to be general educational information to the public. It does not constitute medical advice. If you have specific questions about any medical matter or if you are suffering from any medical condition, you should consult your doctor or other professional healthcare provider.

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