Melatonin
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.
Melatonin at a glance
Melatonin, a hormone produced by the pineal gland in your brain, helps regulate your sleep and wake cycles. Very small amounts of melatonin are found in fruits, nuts, olive oil, and wine. It is also available as a supplement used as a sleep aid.
No clinical evidence shows melatonin is effective as a first-line cancer treatment, but studies show improved outcomes and response to conventional treatmentsthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy when melatonin is used. Melatonin is also effective in managing several common symptoms and side effects of cancer treatments, with some effects in improving your body environment—your terrainthe internal conditions of your body, including nutritional status, fitness, blood sugar balance, hormone balance, inflammation and more—to make it less supportive of cancer. Its safety profile is excellent, although before surgery you should discuss with your oncology team whether to stop use temporarily.
CancerChoices ratings for melatonin
We rate melatonin on seven attributes, with 0 the lowest rating and 5 the highest. We rate the strength of the evidence supporting the use melatonin for a medical benefit, such as improving treatment outcomes or managing side effects.
See how we evaluate and rate complementary therapies ›
Improving treatment outcomes
See More- Melatonin is one of our top therapies beneficial across several cancer types
- Strong evidenceconsistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analyses of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results (this is the CancerChoices definition; other researchers and studies may define this differently) of better survival, tumor response, and remission among people with solid tumors treated with melatonin, mostly when combined with conventional treatments
- Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of better clinical response to chemotherapy among people with advanced cancer with enhanced melatonin levels
- 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 survival among people with advanced cancer treated with melatonin in 2 studies
Optimizing your body terrain
See More- Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently) of lower inflammation in a general population (not specific to people with cancer) treated with melatonin
- Good evidence of less oxidation in a general population (not specific to people with cancer) treated with melatonin
- Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of less oxidation among people with cancer treated with melatonin
- Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of lower levels of procoagulant factors among healthy young men treated with melatonin
- Preliminary evidence of hormone stimulation with 0.5 mg dose melatonin, but inhibition at 5.0 mg dose among healthy people treated with melatonin
- Preliminary evidence of higher white blood cells counts among people with untreatable metastatic solid tumors treated with melatonin and naltrexone
- 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 biomarkers for assessing immune function/inflammation after cancer resection among people with non-small cell lung cancer treated with melatonin in a large study
- No evidence of an effect on hormone levels among postmenopausal women with breast cancer treated with melatonin in 2 preliminary studies
Managing side effects and promoting wellness
See MoreGood evidence of benefit
- Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently) of less anxiety among adults preparing for surgery treated with melatonin, comparable to results with benzodiazepines (not specific to people with cancer); note cautions about the effects of melatonin on anesthesia in Safety and precautions ›
- Good evidence of less anxiety after surgery among people treated with melatonin (not specific to people with cancer)
- Good evidence of less wasting (cachexia) among people with advanced cancer treated with melatonin
- Good evidence of less fatigue during radio/chemotherapy among people with cancer treated with melatonin
- Good evidence of less weakness or lack of energy (asthenia) among people with advanced metastatic cancer
Modest evidence of benefit
- Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of less chemotherapy-related toxicity among people treated with melatonin
- Modest evidence of less severe reductions in blood cell counts during chemo/radiotherapy among people treated with 20 mg oral melatonin, but 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. with 40 mg oral melatonin
- Modest evidence of less toxicity to the heart (cardiotoxicity) during chemotherapy among people with advanced cancer treated with melatonin
- Modest evidence of less neurotoxicity during radio/chemotherapy among people treated with melatonin
- Modest evidence of less oral inflammation (oral mucositis or stomatitis) during radio/chemotherapy among people treated with melatonin
- Modest evidence of better markers of sleep among children and adolescents with chronic insomnia or among adults only with other health conditions treated with melatonin
Preliminary evidence of benefit
- Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of lower incidence of low blood pressure among people with advanced cancer treated with melatonin
- Preliminary evidence of better tolerance of chemotherapy among people with lung cancer treated with melatonin
- Preliminary evidence of better cognitive performance during chemotherapy or hormone therapy among people with breast cancer treated with melatonin
- Preliminary evidence of less depression among people with breast cancer treated with melatonin at doses higher than 3 mg
- Preliminary evidence of less pain during treatment among people with cancer treated with melatonin
- Preliminary evidence of better sleep quality without regard to treatment phase among people with cancer treated with melatonin
- Preliminary evidence of better sleep quality after surgery among people treated with melatonin
- Preliminary evidence of better sleep quality during cancer treatment among people treated with melatonin
- Preliminary evidence of less radiation dermatitis among people treated with a melatonin emulsion
No evidence of an effect
- 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 adverse events after cancer resection among people with non-small cell lung cancer treated with melatonin in a large study
- No evidence of an effect on anxiety after cancer resection among people with non-small cell lung cancer treated with melatonin in a large study
- No evidence of an effect on appetite among people with cancer cachexiaweakness and wasting of the body due to severe chronic illness treated with melatonin in a preliminary study
- No evidence of an effect on fatigue among people with advanced cancer treated with melatonin in a preliminary study
- No evidence of an effect on fatigue after cancer resection among people with non-small cell lung cancer treated with melatonin in a large study
- No evidence of an effect on depression after cancer resection among people with non-small cell lung cancer treated with melatonin in a large study
- No evidence of an effect on hot flashes among among postmenopausal women with breast cancer treated with 3 mg of melatonin in a preliminary study
- No evidence of an effect on pain after cancer resection among people with non-small cell lung cancer treated with melatonin
Reducing cancer risk
See More- Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently) of lower risk of recurrence at 5 years after cancer resection among people with stage 3/4 non-small cell lung cancer treated with melatonin
- Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of a higher risk of breast cancer among people with lower melatonin levels
- Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of lower risk of melanoma recurrence among people treated with melatonin supplements
- Preliminary evidence of less skin damage during sun exposure among people using a topical melatonin cream
- Preliminary evidence of a higher risk of ovarian cancer among people with lower melatonin levels
- Preliminary evidence of a higher risk of prostate cancer or of advanced cancer among men with prostate cancer with lower melatonin levels
Use by integrative oncology experts
See More- Not yet evaluated or mentioned in clinical practice guidelines
- Used widely by integrative oncology experts
Safety
See More- Generally safe, with no serious side effects
- Caution and supervision are needed for people preparing for surgery due to possible interactions with anesthesia
Affordability and access
See More- Widely available without restriction in retail drug stores in the US, although needing a prescription in many other countries
- Generally inexpensive (less than $500 US/year)
Keep reading about melatonin
Author
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.
Reviewers
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.
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.
Last update: April 11, 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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