Melatonin: Safety and precautions - CancerChoices

Melatonin supplements mimic the effects of your own naturally produced melatonin in promoting sleep. Research shows melatonin can have a substantial role in cancer outcomes and side effects.

Safety and precautions

Melatonin is generally considered safe, although a doctor’s supervision is recommended. Melatonin use at recommended doses typically does not lead to dependency, habituation or a drug hangover, all common issues with many pharmaceutical sleep aids.

Side effects or adverse events

Melatonin has a very low toxicity profile and is not associated with significant side effects.1Yeh CM, Su SC et al. Melatonin as a potential inhibitory agent in head and neck cancer. Oncotarget. 2017 Aug 9;8(52):90545-90556. 

  • No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on cognitive performance among healthy volunteers with full-body application of a cream containing 12.5% melatonin compared to placebo in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects2Scheuer C, Pommergaard HC, Rosenberg J, Gögenur I. Effect of topical application of melatonin cream 12.5% on cognitive parameters: a randomized, placebo-controlled, double-blind crossover study in healthy volunteers. Journal of Dermatological Treatment. 2016 Nov;27(6):488-494.
  • “I’ve seen melatonin intensify memories of dreaming which can be disruptive to some. In addition, there is a subset of people in whom melatonin seems to induce more wakefulness.”3Dugald Seely. Comment on this review. April 16, 2022.

Interactions with other therapies

Melatonin should be stopped 5 to 7 days before surgery to avoid magnifying the effects of anesthesia.4Block KI. Life over Cancer: The Block Center Program for Integrative Cancer Care. New York: Bantam Dell. 2009.

Keep reading about melatonin


Nancy Hepp, MS

Lead Researcher
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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS Lead Researcher


Laura Pole, MSN, RN, OCNS

Senior Clinical Consultant
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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, MSN, RN, OCNS Senior Clinical Consultant

Dugald Seely, ND, MSc

Physician, researcher, and CancerChoices advisor
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Dugald Seely, ND, MSc is a naturopathic doctor and clinician scientist living in Ottawa, Canada. Dr. Seely serves patients living with cancer in clinic and is active in research building on the base of evidence for integrative and naturopathic oncology. Helping to pioneer the delivery and development of integrative oncology, Dr. Seely is the founder and executive director of The Centre for Health Innovation (CHI); an adjunct professor at the University of Ottawa, Faculty of Medicine; executive director for research and clinical epidemiology at the Canadian College of Naturopathic Medicine; and president of the Oncology Association of Naturopathic Physicians (OncANP). Dr. Seely has led numerous clinical trials and synthesis research over the past 18 years and has published and presented internationally. Dugald is the father of two and most happy when spending time with his family in the wild outdoors.

Dugald Seely, ND, MSc Physician, researcher, and CancerChoices advisor

Last update: July 3, 2024

Last full literature review: October 2021

CancerChoices provides information about integrative in cancer care, a patient-centered approach combining the best of conventional care, self care and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocial therapy, and acupuncture therapies and self-care lifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

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