The Role and Efficacy of Melatonin

Melatonin, a hormone synthesized by the pineal gland from tryptophan, is best known for improving sleep. The secretion of melatonin by the pineal gland shows a strong physiological cycle law, which is related to the alternation of day and night, with less secretion during the day and more secretion at night.

The pineal gland reduces the number of awakenings during sleep by shortening the wake-up time before bedtime and the time to fall asleep; by shortening the light sleep stage and prolonging the deep sleep stage, it reduces the wake-up threshold the next morning.

One category is people who need jet lag and shifts. This population has difficulty falling asleep and waking up due to deviations in circadian rhythms and expected sleep and work hours. Sleep and wake times can be adjusted by supplementing exogenous melatonin. The other category is middle-aged and elderly people. With age, the pineal gland gradually shrinks until it becomes calcified, and the corresponding secretion of melatonin decreases, resulting in a weakening of the rhythm of the biological clock, resulting in decreased sleep and early awakening. By supplementing melatonin, it can promote sleep and deepen sleep.

Although melatonin is generally safe, there is insufficient research on its safety in children and pregnant women, so it is not recommended for certain special populations, such as children and pregnant women. In addition, it is not suitable for people with special diseases such as depression.

For people who simply need to improve their sleep, it is recommended to take melatonin about an hour before bedtime. For people who need jet lag, if you want to take melatonin to prevent jet lag, you should start taking melatonin a few days before departure, preferably about an hour before going to bed at the destination, to help the body adapt to the new time zone.

Melatonin’s MT1 and MT2 receptors are highly susceptible to “desensitization,” a marked decrease in activity following exposure to doses of the hormone above normal concentrations. When people buy health products that can contain melatonin, they need to clarify its single-dose specification. If you bought a tablet, you can take it apart. It is recommended to start with a small dose, 0.1mg-0.3mg melatonin can improve sleep, and 0.3mg-0.5mg melatonin can improve insomnia caused by circadian rhythm disorders. Long-term use of high doses of melatonin should be avoided unless advised by a physician to reduce the chance of developing melatonin resistance.

For people who are prone to insomnia, in addition to considering supplementing exogenous melatonin, it is also recommended to make full use of endogenous melatonin. On the one hand, the rhythm of melatonin secretion is often closely related to the cycle of light changes in the environment. Light source stimulation before bed can inhibit the secretion of melatonin. Therefore, it is recommended to avoid looking at mobile phones and tablets for a long time before going to bed. In addition, you also need to pay attention to the problem of indoor lighting, and if necessary, you can speed up falling asleep by pulling curtains, wearing eye masks, etc. On the other hand, it is recommended to go to bed and get up on time to form a more regular sleep schedule.

It’s not that you can’t sleep, melatonin is useful.

There are many reasons for insomnia. Only insomnia related to circadian rhythm (biological clock) imbalance can melatonin be effective. For healthy people who do not have melatonin deficiency and have difficulty falling asleep due to anxiety and other reasons, the actual effect of melatonin is very “weak”.

Therefore, melatonin is only useful for workers who work day and night shifts, people whose sleep time is shifted later, and people who need jet lag. Trying to use melatonin to prolong total sleep time also has little effect.

For now, it is safe to use for at least a few days or weeks. However, if taken for a long time, it may cause:

1. Affect the body’s melatonin secretion;
2. Increase the burden on liver and kidney;
3. Affect fertility;
4. Poor spirit, distracted attention, reduced reaction speed and sensitivity; (mechanical operations, dangerous operators must be careful)
5. Melatonin can interact with certain medications (with blood clotting disorders, depression, epilepsy, people with organ transplants, people taking aspirin…).