Melatonin is a hormone produced by the pineal gland in your brain. It’s primarily responsible for regulating your body’s circadian rhythm to manage your natural sleep cycle. Darkness triggers the body to make more melatonin, which signals the body to sleep. Light decreases melatonin production and signals the body to be awake. Some people who have trouble sleeping have low levels of melatonin. Therefore, it’s often used as a sleep aid to combat issues like insomnia. It's thought that adding melatonin from supplements might help them sleep. People most commonly use melatonin for insomnia and improving sleep in different conditions, such as jet lag.
What are the health benefits of taking melatonin?
Jet lag affects people when they travel by air across multiple time zones. you may not feel well overall and you may have disturbed sleep, daytime tiredness, impaired functioning, and digestive problems. Research suggests that melatonin supplements may help with jet lag. This is based on medium-sized reviews from 2010 and 2014. Studies indicate that melatonin may be better than a placebo in reducing symptoms of jet lag after flights.
Delayed sleep-wake phase disorder (DSWPD)- People with DSWPD have trouble falling asleep at the usual times and waking up in the morning. They typically have difficulty getting to sleep before 2 to 6 a.m. and would prefer to wake up between 10 a.m. and 1 p.m. Melatonin supplements appear to help with sleep in people with DSWPD. This is based on a clinical practice guideline, a small review, and a more recent study. It indicated that taking melatonin 1 hour before the desired bedtime combined with going to bed at a set time led to several improvements. Those improvements included falling asleep an average of 34 minutes earlier, better sleep during the first third of the night, and better daytime functioning.
Sleep problems in children can have undesirable effects on their behavior, daytime functioning, and quality of life. Children with certain conditions, such as atopic dermatitis, asthma, attention-deficit hyperactivity disorder (ADHD), or autism spectrum disorder (ASD), are more prone to sleep problems than other children. There are no overall guidelines on the best approach to improving sleep in children. The list below shows the review’s results on melatonin’s short-term effects for children with specific conditions.
- Children with ASD fell asleep 37 minutes earlier and slept 48 minutes longer.
- Children with ADHD fell asleep 20 minutes earlier and slept 33 minutes longer.
- Children with atopic dermatitis fell asleep 6.8 minutes earlier and slept 35 minutes longer.
Children with chronic sleep-onset insomnia fell asleep 24 minutes earlier and slept 25 minutes longer.
Because there aren’t many studies on children and melatonin supplements, there are uncertainties about what dose to use and when to give it. Because melatonin is a hormone, it’s possible that melatonin supplements could affect hormonal development, including puberty, menstrual cycles, and overproduction of the hormone prolactin, but it's not known for sure. However, though melatonin is associated with fewer side effects than other sleep medications, it may be less effective.
Melatonin supplements appear to be helpful in reducing anxiety before surgery, but it’s unclear if it helps to lower anxiety after surgery. This is based on a 2015 review. The review found strong evidence that melatonin is better than placebo at reducing anxiety before surgery. Melatonin supplements may be as effective as standard treatment (the antianxiety medicine midazolam). However, the results on melatonin for reducing benefits anxiety after surgery were mixed. Seasonal affective disorder (SAD), also called seasonal depression, is a common condition that is estimated to affect up to 10% of the population worldwide. This type of depression is related to changes in the seasons and occurs each year around the same time, with symptoms typically appearing in late fall to early winter. Some research indicates that it could be linked to changes in your circadian rhythm caused by seasonal light changes. Because melatonin plays a role in regulating circadian rhythm, low doses are often used to decrease symptoms of seasonal depression. However, research is needed to determine how melatonin may impact symptoms of seasonal depression.
Studies of melatonin supplements on cancer symptoms or treatment-related side effects have been small and have had mixed results. Keep in mind that unproven products should not be used to replace or delay conventional medical treatment for cancer. People with insomnia have trouble falling asleep, staying asleep, or both. When symptoms last a month or longer, it’s called chronic insomnia. According to practice guidelines from the American Academy of Sleep Medicine (2017) and the American College of Physicians (2016), there’s not enough strong evidence on the effectiveness or safety of melatonin supplementation for chronic insomnia. The American College of Physicians guidelines strongly recommend the use of cognitive behavioral therapy for insomnia (CBT-I) as an initial treatment.
Human growth hormone (HGH) is a type of hormone that is vital to growth and cellular regeneration. Higher levels of this important hormone have also been linked to increases in both strength and muscle mass. Some small studies have found that supplementing with melatonin may increase levels of HGH in men. One small study of eight men found that both low (0.5 mg) and high (5 mg) doses of melatonin were effective at increasing HGH levels. Another study of 32 men showed similar results. However, larger-scale studies are needed to understand how melatonin may affect levels of HGH in the general population.
Melatonin is high in antioxidants that can help prevent cell damage and keep your eyes healthy.
Research suggests that melatonin could be beneficial in treating conditions like glaucoma and age-related macular degeneration (AMD). In a study of 100 people with AMD, supplementing with 3 mg of melatonin for 6–24 months helped protect the retina, delay age-related damage, and preserve visual clarity. Additionally, a rat study found that melatonin decreased the severity and incidence of retinopathy — an eye disease that affects the retina and can result in vision loss.
However, research is limited, and additional human studies are needed to determine the effects of long-term melatonin supplements on eye health.
Gastroesophageal reflux disease (GERD) is a condition caused by the backflow of stomach acid into the esophagus, resulting in symptoms like heartburn, nausea, and belching. Melatonin has been shown to block the secretion of stomach acids. It also decreases the production of nitric oxide, a compound that relaxes your lower esophageal sphincter, allowing stomach acid to enter your esophagus. For this reason, some research suggests that melatonin may be used to treat. A study compared the effects of omeprazole and a dietary supplement containing melatonin along with several amino acids, vitamins, and plant compounds in 351 people with GERD. After 40 days of treatment, 100% of people taking the melatonin-containing supplement reported a reduction in symptoms compared to only 65.7% of the group taking omeprazole.
Melatonin can be taken in doses of 0.5–10 mg per day. However, because not all melatonin supplements are the same, it’s best to stick to the recommended dosage on the label to avoid adverse side effects. You may also want to start with a lower dose and increase as needed to find what works for you. If you’re using melatonin to improve sleep quality, try taking it 30 minutes before bedtime for maximum effectiveness.
Risk and side effects:
Research shows that melatonin is safe and non-addictive for both short- and long-term use in adults. Additionally, despite concerns that supplementing with melatonin may decrease your body’s ability to produce it naturally, several studies show otherwise. However, because long-term studies on the effects of melatonin are limited to adults, it’s not currently recommended for children or adolescents.
If you’re pregnant or nursing a child, it’s especially important to see your healthcare provider before taking any medicine or supplement, including melatonin. Some of the most commonly reported side effects associated with melatonin include nausea, headaches, dizziness, and sleepiness. Melatonin may also interact with certain medications, including antidepressants, blood thinners, and blood pressure medications. If you’re taking any of these medications, talk to your doctor before taking melatonin to prevent adverse effects.