I use this word a lot, multiple times a day usually. Melatonin and myself share a commonality, our business is both ‘Sleep’! It comes up in every conversation I have with a family as I am explaining the role that sleep plays in their child’s life and when explaining about the importance of a sleep schedule. Melatonin is responsible for so much..but what is it really?
According to Medical News Today, “Melatonin is a hormone, produced in the brain, that carries out a wide range of roles in the body; the most well known of its functions is the control of circadian (daily) rhythms.” Similarly, Web MD states “Melatonin is a hormone made by the pineal gland. That’s a pea-sized gland found just above the middle of your brain. It helps your body know when it’s time to sleep and wake up.”
So we know now 1. Melatonin is a hormone, and 2. It is a hormone responsible for sleep. However, the definitions also mentioned circadian rhythms and in the latter, a simplified explanation of “when to sleep and when to wake up,” which is essentially what the circadian rhythm is. Imagine a clock inside your body, telling you (via signals from you brain) when to be tired, when to wake up, when to be hungry. This clock is your circadian rhythm, or internal clock. Everyone (aged 4 months and older) has one!
But does this all happen on its own? Well, sort of. Although, many of these signals are biological, they are also greatly affected by environmental cues like sunlight and temperature. The whole system works quite nicely together to make sure your body gets enough sleep. This is how The National Sleep Foundation explains the process. “When it’s dark at night, your eyes send a signal to the hypothalamus that it’s time to feel tired. Your brain, in turn, sends a signal to your body to release melatonin, which makes your body tired. That’s why your circadian rhythm tends to coincide with the cycle of daytime and nighttime”
Adults will get a boost of melatonin in the early evening as well as mid day (between 1:00-3:00pm). Some will contribute this sleepy feeling to a hearty lunch, but that is not the case. It is for this reason that some Doctors will suggest this as the optimal nap time for adults (if your schedule allows)
Babies, children and teenagers follow their own circadian rhythm that differs from adults. Babies have 2 natural waves of melatonin throughout the day, and a teenager’s whole biological sleep schedule shifts forward.
In any case, it is important to understand and listen to your body signals, aiming to follow your circadian rhythm as closely as possible for optimal health.