*Nothing in this article constitutes medical advice. Seek the guidance of a physician if you have any questions.*
Chronic sleeplessness is an epidemic in the United States. Each night, about 60 million Americans do not achieve a desired length or quality of sleep. Many of these people are turning to home remedies to attempt to cure their sleepless ailing. One of the most common over-the-counter remedies is the compound melatonin. Let’s take a closer look at what exactly melatonin is and understand whether it is useful in treating insomnia.
What Is Melatonin?
In order to understand what melatonin is and why it is important, we must first understand some basic parts of its chemistry and biology.
Melatonin is part of a class of compounds called “substituted tryptamines.” Tryptamines, in general, are a specific metabolite (a product of metabolism) derived from the amino acid tryptophan. Tryptophan is the same amino acid that is present in high quantities on Thanksgiving and makes us tired.
The “substituted” part of “substituted tryptamine” comes from the fact that all tryptamines share a common backbone structure. This means that various other molecules are formed from the same backbone, and thus, they function in similar ways in our bodies. Many substituted tryptamines are familiar:
- Serotonin: This is an extremely important and complex neurotransmitter that modulates many functions including cognition, reward pathways, mood, learning, and memory.
- Psychedelics: Many of the most common recreational and medical psychedelics, such as DMT, psilocybin, and psilocin are naturally occurring substituted tryptamines.
- Zolmitriptan: This compound is sold under the trade name Zomig and is a potent migraine and cluster headache medication.
Where Does It Come From?
We understand the structure of melatonin, now, but where does it come from? Melatonin is naturally released inside of our brains from the pineal gland. This gland is a tiny, nut-shaped protrusion on the opposite side of the brain stem from the pituitary gland. Among other roles, the pineal gland is largely responsible for regulating the secretion of sex hormones from the pituitary gland.
Mechanism of Action
Melatonin is a specific hormone released from the pineal gland, but what happens next? let’s better understand what exactly melatonin does once inside the body.
Melatonin is a full agonist of melatonin receptor 1 and melatonin receptor 2. The “full agonist” means that the cell produces a “full and complete” response when stimulated by melatonin. This is in contrast to a “partial agonist” or a “co-agonist.”
Once melatonin binds to its receptors, several things can happen. Broadly, there are three distinct effects realms in which melatonin operates.
- Regulation of circadian rhythms: Our circadian rhythm is what regulates each of our body’s internal clocks. This is what “tells” us to get tired at night and when to wake up in the morning.
- Antioxidant functions: Oxidants are harmful, reactive molecules that can cause cell (and DNA) damage. Antioxidants are compounds that have the capability of turning oxidants into less harmful molecules. Melatonin is one of those such antioxidants. Melatonin is observed at very high concentrations in mitochondrial fluid, and this may indicate that melatonin is an important mitochondrial antioxidant.
- Immune functions: Although this specific mechanism is not well understood, melatonin seems to aid in the inflammatory response. Further research is needed to understand how this happens, exactly.
Why Would Someone Take Melatonin?
In order to understand whether you should take melatonin, we should first understand why any person, in theory, would take melatonin.
Specific Sleep Disorders
Melatonin is likely most commonly used to treat a multitude of different sleep disorders. Evidence strongly suggests that melatonin is an important sleep regulator, so the logic of using melatonin to treat insomnia, REM sleep disorders, and delayed sleep phase syndrome is reasonable, in theory (more on this later).
Recently, new evidence has suggested that melatonin may be useful in the treatment of dementia. The researchers concluded that after the onset of dementia (in their specific aims, due to Alzheimer’s), melatonin was ineffectual. But, the compound was somewhat useful in delaying the onset of and treating the symptoms of sun downing.
Shift Word Disorder and Jetlag
Some individuals may also take melatonin to treat two common sleep disorders: shift work disorder (SWD) and jetlag. SWD is a condition whereby individuals who work off-hours and nights begin to have difficulty sleeping during the day. Jetlag is symptomatic in an individual after they move (typically) more than two time zones in either east/west direction. Limited evidence suggests that melatonin is effective in either case.
Should I Take Melatonin?
And now, let’s take a look at the actual question at hand. Arguably, most individuals will be attempting to self-medicate with melatonin to treat some sort of perceived sleep issues, whether diagnosed or not. Unfortunately, the clinical and research data do not support the conclusion that melatonin is productive for this purpose.
- A 2017 study conducted by the Medical University of South Carolina found that patients who took melatonin fell asleep 6 minutes earlier, on average, than the placebo control.
- A 2014 meta-analysis concluded that “Results from the meta-analyses showed the most convincing evidence for exogenous melatonin use was in reducing sleep onset latency in primary insomnia (p = 0.002), delayed sleep phase syndrome (p < 0.0001), and regulating the sleep-wake patterns in blind patients compared with placebo.” These results indicate that, for sighted individuals or people without diagnosed delayed sleep phase syndrome, melatonin is not effective at improving sleep quality or duration.
- Another 2015 study found that, in regards to treating mild sleep disorders, “Evidence for benzodiazepine hypnotics, melatonin agonists, and antidepressants in general populations and for most pharmacologic interventions in older adults was generally insufficient.”
All of these results seem to point towards the same conclusion: there is little to no evidence to suggest that taking melatonin before bedtime will improve sleep quality to a meaningful degree. That being said, after checking with your doctor that melatonin is safe to take for you, there is nothing wrong with giving this substituted tryptamine a shot!