For about 15 years, melatonin supplementation has been studied extensively -- mainly in Europe -- for treating cancer. In studies conducted in laboratory animals or human cancer cell cultures, melatonin appeared to keep some types of tumors from spreading as rapidly as untreated tumors. Several studies have also been conducted in humans with advanced tumors. In general, supplemental melatonin appeared to help prevent or delay the spread of tumors for many of these individuals, but much more study is needed to confirm this finding. In animal studies, certain cancers, such as leukemia, may have been worsened by supplemental melatonin. For the treatment of cancer, melatonin is most often injected into muscle tissue, but injectable melatonin is not available for use.

Melatonin may have additional positive effects. In recent studies, melatonin has shown some value for easing the withdrawal from benzodiazepine drugs for individuals who have become dependent on those drugs. Other studies show that melatonin supplements may also be useful in helping individuals who are trying to stop smoking. It has also shown some effectiveness in lowering blood pressure levels in several human studies and reducing blood cholesterol levels in limited animal studies. Other recent research indicates that melatonin is concentrated in certain cells (which may also produce natural melatonin) in the stomach and intestines, where it may help prevent damage caused when non-steroidal anti-inflammatory drugs are taken on a long-term basis. In one study, supplemental melatonin may have prevented cluster headaches in individuals susceptible to having that type of headache. Because very high oral doses of melatonin are believed to decrease fertility for women, some inconclusive research has been done into its use as a contraceptive. In other studies, a liquid form of melatonin was applied to the skin to serve as protection from ultraviolet light and sunburn. In laboratory animals, melatonin may help to prevent the development of Type 1 diabetes. While clinical research continues for the use of melatonin in these and many other conditions, no definitive results prove that melatonin is effective for any of them.

NOTE: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It should not be construed to indicate that the use of the product is safe, appropriate, or effective for you. Consult your healthcare professional before taking the product.