Naturally synthesized in the pineal gland and gastrointestinal tract, melatonin is a primary hormone involved in regulating the body’s circadian rhythm. In addition, melatonin is classified as an antioxidant. Though the body naturally produces melatonin, certain physiological conditions require additional supplementation.
Low levels of melatonin in the blood can cause a disturbance in the circadian rhythm, as it is a main component of the sleep-wake cycle. A research review suggests melatonin supplementation is effective in normalizing circadian rhythm. It can adjust the sleep cycle among individuals with jet lag, varied work schedules, or nighttime shift work.
Poor sleep quality is a common complaint among older individuals, as melatonin production may become impaired. One study found melatonin supplementation (2 mg) improved sleep and morning alertness in 170 subjects (55 years and older) with poor sleep quality. In addition, discontinuing melatonin did not cause withdrawal symptoms. Furthermore, melatonin was given to 51 patients with cognitive disabilities and sleep disturbances finding it improved the onset of sleep and increased total sleep time.
Several studies have indicated melatonin is safe and effective for children with sleep disturbances. A double-blind study recruited 62 children (6 to 12 years old) with sleep problems to take melatonin (5 mg) or a placebo at night. The melatonin group showed improvements in their sleep cycle, as they fell asleep faster and awoke more refreshed.
One study reviewed melatonin’s benefits on sleep disturbances in 105 hyperactive children, ages 6 to 12 years. A four-week administration of melatonin (3 or 6 mg) helped to restore the circadian rhythm and enhanced sleep time.
Gastrointestinal upset (indigestion, heartburn, bloating, etc.) continues to be a prevalent complaint for many people. More recently researchers found melatonin is largely synthesized in the gastrointestinal tract (400 times more than the pineal gland). Melatonin’s secretion in the GI tract offers a wide range of gastrointestinal benefits from indigestion to chronic bowel ailments. It even scavenges free radicals to protect the stomach lining from stress-induced damage.
One study reviewed melatonin’s inhibiting effects on gastric upset by comparing a dietary supplementation (melatonin, l-tryptophan, vitamin B6, folic acid, vitamin B12, methionine and betaine) with a traditional drug used for gastric upset. Every subject (176 patients) taking the melatonin combination experienced a decrease in symptoms after 40 days of treatment. In contrast, only 65.7% of the group taking the traditional drug (115 subjects) noticed a decline in symptoms.
A twelve-week study recruited 60 patients with stomach pain to take melatonin (5 mg) or a placebo. Patients in the melatonin group had a complete (56.6%) or partial (30%) reduction in frequency and intensity of stomach pain, while the majority of the placebo group (93.3%) did not experience any improvement in symptoms.
One study reviewed the effects of melatonin in 40 female patients with chronic bowel ailments. Subjects were randomly assigned to receive melatonin (3 mg) or a placebo at bedtime for two weeks. Patients taking melatonin experienced less abdominal pain. A similar study found the same therapeutic results of melatonin (3 mg) in alleviating bowel ailments among 14 female patients.
Anxiety and Mood
Melatonin may relax the nervous system during stressful situations. One study gave melatonin (4 mg) to healthy female subjects and measured their startle response during a stress-induced modulation. Melatonin lowered the startle response and elicited a calmer reaction that was indicated by a lower heart rate.
The role of melatonin on improving sleep quality has shown that it can also generate a positive mood. One study compared the mood enhancing effects of melatonin with common mood boosting drugs, such as serotonin reuptake inhibitors (SSRIs). Though SSRIs have been viewed as successful treatments in improving mood, they often disrupt the sleep cycle. The study suggested melatonin could be a promising alternative to improve mood by normalizing sleep patterns.
Melatonin’s effect on memory has also been investigated, as its antioxidant activity may reduce oxidative stress that leads to neurodegenerative ailments. One study focused on improving spatial memory by administering a combination of melatonin, alpha lipoic acid, and trans resveratrol to rats for 18 days. Researchers saw significant improvement in spatial memory suggesting melatonin reduced the accumulation of oxidative stress.
Another cognitive study found a low dose of melatonin (0.75 mg) improved memory function in young volunteers. In addition, memory was optimal even two weeks after the drug was terminated.
Brain injuries that develop in infants before or right after birth can lead to learning disabilities. An animal study investigated the effects of melatonin on preventing learning ailments in five day old mice with brain injuries. Results indicated melatonin reduced the formation of lesions caused by brain injuries and helped to prevent learning disabilities.
Melatonin’s widespread involvement in physiological processes can include cardiovascular health. One study suggests melatonin can aid stress-induced blood pressure imbalances, as a reduction in melatonin levels was apparent in rats with abnormal blood pressure levels. Melatonin administration decreased components related to irregular blood pressure, while it increased amino acids (Taurine and GABA) associated with normal heart function.
The cardiovascular benefits may extend further, as melatonin has several antioxidant functions that include scavenging and reducing the formation of free radicals, stimulating antioxidative enzymes, and enhancing the efficiency of other antioxidants.
Additional Information – Dosage & Interactions
As a dietary supplement, take one capsule one hour before bedtime as needed, or as directed by a physician.
0.3 to 3 mg nightly for sleep disturbance or jet lag
The maximum safe dosage of this supplement has not been determined for children, pregnant or nursing women, or those with severe liver or kidney disease. As with all supplement regimens, please consult your physician prior to use.
Do not take melatonin if you have liver disease, neurological disorders (seizures, etc.), or depression.
DO NOT operate machinery or drive a motor vehicle while taking this product as it may cause drowsiness. Taking too much may cause morning grogginess or undesired drowsiness. This product is not intended for use by anyone under 25 years of age. If you are pregnant or nursing, consult a physician prior to using this product.
Consult your physician before supplementing with Melatonin if you are taking the following medications.
Fluvoxamine (Luvox); Corticosteroids; Sedating drugs (benzodiazepines, etc.); Nifedipine (Adalat, Procardia); Warfarin (Coumadin); Interleukin-2
*Statements made herein have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.
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