Melatonin is a hormone produced naturally by the pineal gland in the centre of the human brain. It plays a crucial role in helping us to fall asleep and regulating the sleep-wake cycle, also known as the circadian cycle or rhythm. Its secretion, which is triggered by darkness, promotes sleep.
Here's an overview of its roles in the body, as identified to date by research:
Sleep-wake alternation: often called the "sleep hormone", melatonin levels play an important role in the transition from wakefulness to sleep, and vice versa. Secreted in response to darkness, it signals to the body that it is time to go to sleep.
Synchronisation of circadian rhythms: the conductor of the body's internal clock, governed by alternating light and darkness, melatonin plays an essential role in regulating physiological functions, such as blood pressure, body temperature and the cascading secretion of other hormones.
Antioxidant: melatonin also acts as a powerful antioxidant in the body, helping to protect cells from damage caused by free radicals. Melatonin can help protect cells from this oxidative stress, boost the immune system and maintain tissue health and function.
Fertility: melatonin also plays a significant role in fertility. It influences reproductive hormone secretion and is found in the follicular fluid of the ovaries, helping to protect and develop oocytes.
Effects on mental health: some research suggests that melatonin may have beneficial effects on mental health, particularly by helping to reduce anxiety and depression. However, there is no certainty, and the Anses (French National Health and Safety Agency) does not recommend taking melatonin as an antidepressant.
Melatonin fulfils several important functions in the body, from regulating sleep and modulating circadian rhythms to cell protection and fertility.







