What are the benefits and side effects of melatonin?

Generally, the benefits of melatonin include regulating sleep rhythms, improving sleep quality, exerting antioxidant effects, modulating immune function, and assisting in regulating endocrine function. Side effects may include dizziness, drowsiness, gastrointestinal discomfort, poor mental condition, interference with hormone secretion, and blood pressure fluctuations. Detailed analysis is as follows:

I. Benefits of Melatonin

1. Regulating Sleep Rhythm

Melatonin helps adjust the body's biological clock, making the sleep cycle more regular. It is particularly effective in regulating circadian rhythm disorders caused by shift work or cross-time-zone travel, enabling individuals to adapt more quickly to new schedules.

2. Improving Sleep Quality

Melatonin can deepen sleep, reduce nighttime awakenings, and provide more continuous and restful sleep, resulting in feeling more energetic upon waking.

3. Antioxidant Effects

Melatonin has certain antioxidant properties, capable of scavenging free radicals in the body, reducing oxidative damage, helping delay cellular aging, and offering benefits for maintaining overall health and skin condition.

4. Modulating Immune Function

To some extent, melatonin can enhance the body's immune capacity, helping defend against external pathogens and reducing the risk of illness.

5. Assisting in Regulating Endocrine Function

Melatonin has a regulatory effect on the endocrine system, influencing the secretion and release of other hormones, such as thyroid hormones and sex hormones, contributing to their regulation and balance.

II. Side Effects of Melatonin

1. Dizziness and Drowsiness

Exogenous melatonin supplementation might interfere with the normal neurotransmitter transmission and regulatory mechanisms in the nervous system, particularly affecting neural pathways related to wakefulness and alertness, thereby altering nerve signal conduction and causing symptoms like dizziness and drowsiness. The higher the dose, the more pronounced this interference may be.

2. Gastrointestinal Discomfort

Melatonin may irritate gastrointestinal mucosa and affect the normal contraction and relaxation of gastrointestinal smooth muscles. It may also interfere with digestive enzyme secretion and gastrointestinal motility rhythms, thereby affecting the digestion and transit of food in the gastrointestinal tract, leading to symptoms such as nausea, vomiting, diarrhea, and abdominal pain.

3. Poor Mental Condition

Human mental states are closely related to neurotransmitters. Melatonin intake may affect the balance of neurotransmitters such as serotonin and dopamine, which play crucial roles in maintaining mental vitality, attention, and memory. Imbalances in neurotransmitters can lead to fatigue, lack of concentration, and decreased memory.

4. Interference with Hormone Secretion

The human endocrine system has complex feedback regulatory mechanisms. Long-term, high-dose supplementation of exogenous melatonin may cause the body's endocrine regulatory system to mistakenly perceive its own melatonin production as sufficient, thus inhibiting melatonin secretion by the pineal gland. Additionally, hormones within the endocrine system are interrelated and influence each other; abnormal fluctuations in melatonin levels may disrupt the secretion and regulation of other hormones, such as affecting the hypothalamic-pituitary-gonadal axis, thereby influencing estrogen and testosterone levels and affecting physiological functions.

5. Blood Pressure Fluctuations

Melatonin has a certain regulatory effect on the cardiovascular system, potentially influencing blood pressure by affecting vascular smooth muscle tone and sympathetic nervous system activity. For individuals with inherently unstable blood pressure, such as those with hypertension or hypotension, melatonin may disrupt their already fragile blood pressure balance mechanism, leading to abnormal vascular contraction or relaxation functions, causing blood pressure fluctuations, and increasing the risk of cardiovascular diseases.

When taking melatonin, strictly follow the instructions or a physician's advice regarding dosage and administration timing; do not arbitrarily increase the dose or prolong the duration of use. Also, avoid taking it with other drugs that may affect sleep or the nervous system to prevent potential drug interactions.