March 2013

Melatonin May Not Reduce Weight Loss in Cancer Patients

Contrary to previous findings, a recent study suggests that melatonin supplementation may not increase appetite or reduce weight loss in advanced cancer patients.

Melatonin is a hormone produced in the brain by the pineal gland from the amino acid tryptophan. The synthesis and release of melatonin are stimulated by darkness and suppressed by light, suggesting the involvement of melatonin in circadian rhythm and regulation of diverse body functions. Levels of melatonin in the blood are highest prior to bedtime.

There are several early-phase and controlled human trials of melatonin in patients with various advanced-stage malignancies, including brain, breast, colorectal, gastric, liver, lung, pancreatic and testicular cancers, as well as lymphoma, melanoma, renal cell carcinoma and soft-tissue sarcoma. Currently, no clear conclusion can be drawn in this area. There is not enough definitive scientific evidence to discern if melatonin is beneficial against any type of cancer, whether it increases (or decreases) the effectiveness of other cancer therapies, or if it safely reduces chemotherapy side effects.

In a recent study, researchers sought to evaluate the potential effects of melatonin supplementation on weight loss, appetite and quality of life in advanced lung and gastrointestinal cancer patients. Most individuals with cancer will lose weight at some time with their disease. Losing 10 or more pounds without dieting or intending to lose weight can be one of the first symptoms experienced with cancer, particularly cancers of the pancreas, stomach, esophagus or lung.

Patients were randomly assigned to receive 20 milligrams of melatonin or placebo daily for 28 days. Various symptoms, including weight and quality of life were assessed at the beginning and end of the 28 day study.

The researchers found that significant differences were lacking for weight loss, appetite and quality of life between the melatonin and placebo groups following the 28 days of treatment. The authors concluded that melatonin may not improve these symptoms in advanced cancer patients. Further research is warranted.

For more information about integrative therapies for cancer, please visit Natural Standard's Comparative Effectiveness Database.

For more information about melatonin, please visit Natural Standard's Foods, Herbs & Supplements Database.

To comment on this story, please visit Natural Standard's blog.


  1. Del Fabbro E, Dev R, Hui D, et al. Effects of Melatonin on Appetite and Other Symptoms in Patients With Advanced Cancer and Cachexia: A Double-Blind Placebo-Controlled Trial. J Clin Oncol. 2013 Feb 25. 
  2. Natural Standard: The Authority on Integrative Medicine. 

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