Melatonin is a hormone produced by the pineal gland, a gland located in the middle of the brain. The hormone helps regulate the body’s circadian rhythm (sleep-wake cycle). Melatonin levels increase after sunset, and they remain elevated overnight. They decrease sharply around sunrise, and this causes individuals to wake from sleep.
Melatonin supplements are available in tablet, liquid, and gummy formulations, and they are used primarily as natural sleep aids. The recommended dosage of melatonin is based on the patient’s age.
Pediatric patients can safely take up to six milligrams of melatonin, and doctors suggest starting with a dose of 0.5 milligrams for this age group. The dose should be taken thirty to sixty minutes before bedtime. Adults should start with a dose of 0.2 milligrams, and they can work up to a maximum dose of five milligrams.
Patients in this age group should take melatonin supplements sixty minutes before bed. For older adults over sixty years old, the recommended starting dose is one milligram, and the suggested maximum dose is six milligrams.
The major uses, benefits, side effects, and precautions associated with melatonin supplements are discussed below.
How Melatonin Works
Melatonin is a fat-soluble hormone synthesized from an amino acid called tryptophan. The hormone sends signals to the brain’s receptor agonist, and it binds to receptors that reduce nerve activity.
Research shows it can help reduce levels of dopamine, a hormone that helps patients stay awake. Studies indicate melatonin is also involved in regulating body temperature and blood pressure.
While the exact manner in which melatonin works is currently unclear, researchers believe its involvement in the regulation of body temperature, blood pressure, and the reduction of nerve activity could be responsible for its ability to promote sleep and relaxation.
Ongoing research is being conducted to discover more about how this occurs.
Melatonin supplements are commonly used as sleep aids to reduce insomnia and jet lag. Studies suggest the supplements can improve sleep duration and reduce the amount of time it takes for a patient to fall asleep, and they may also improve the quality of their sleep.
In studies of individuals with jet lag, melatonin supplements have shown the potential to prevent shifts in sleeping and waking times as well.
Additional research suggests melatonin supplements may be beneficial for the relief of migraines and cluster headaches, and a study from 2014 reported tinnitus patients who used melatonin supplements had improvements in their symptoms.
Researchers believe the supplements could be useful in slowing cognitive decline associated with Alzheimer’s disease, and patients with cancer may wish to ask their oncology team about whether melatonin could support their treatment.
While the exact mechanism is unclear, some small studies suggest melatonin could help keep cancer from starting and advancing. In addition, research published in 2017 discovered melatonin supplements could improve how a tumor responds to the radiation therapy used in cancer treatment.
Potential Side Effects
Melatonin supplements are recognized as generally safe for most individuals, and side effects are uncommon. Potential side effects for adults include headaches, dizziness, drowsiness, and nausea. Daytime drowsiness is especially common.
Patients who take larger doses may be at an increased risk of side effects, and melatonin supplements have produced morning hangovers in some individuals who exceeded the recommended dose. Some adults have reported depression, irritability, and stomach pain while taking melatonin.
In addition to nausea, dizziness, and headaches, pediatric patients have experienced diarrhea and bedwetting as a result of taking melatonin supplements. It appears these supplements may increase the risk of seizures in children who have severe neurological conditions.
Less common side effects that may develop with melatonin use include anxiety, vivid dreams or nightmares, confusion, loss of appetite, joint or back pain, and changes in blood pressure.
Precautions to Remember
Melatonin supplements are not regulated in the United States, and patients should research brands before making a purchase. It is important to buy a reputable brand that has effective measures for quality control, and patients might also want to research brands to check for potency levels and any added ingredients.
Patients could begin to feel drowsy around thirty minutes after taking a melatonin supplement, and this could persist for at least one hour.
Experts recommend that individuals avoid driving and operating heavy machinery if they feel very sleepy after consuming melatonin, particularly if this sleepiness persists the next day. In general, it is suggested patients avoid driving and using heavy machinery for at least four hours after taking a dose of melatonin.
Melatonin supplements should not be used by patients with epilepsy or autoimmune conditions, and individuals with diabetes, liver disease, kidney disease, or heart problems could be at an increased risk of side effects.
Patients should check with their doctor before using melatonin if they are pregnant, breastfeeding, or taking any other medication.
Melatonin supplements are only intended for short-term use, and patients should speak with their doctor if their symptoms persist after starting melatonin or if new symptoms develop while taking the supplements.
Caffeine could increase or prolong the sedation caused by melatonin, and patients should avoid caffeinated beverages and energy drinks during treatment with melatonin. Alcohol consumption should be avoided as well.
Potential Medication Interactions
Melatonin supplements could interact with many different types of medication. Patients who take sedatives should not use these along with melatonin, and individuals who take fluvoxamine also need to avoid taking melatonin.
Using melatonin supplements during treatment with diabetes medicines could reduce the effectiveness of these medicines and lead to an increase in blood glucose.
Interactions are known to exist between melatonin and blood thinners such as warfarin, acetylsalicylic acid, and heparin too, and patients on these medicines should check with their doctor before taking melatonin supplements.
Individuals who take nifedipine should check with their healthcare provider about whether it is safe for them to use melatonin as well.
Patients can ask their healthcare provider to check their current medication list for potential medication interactions with melatonin, and they should ask the pharmacist to double-check for interactions before any medication is dispensed.