Melatonin, a natural antioxidant, plays a crucial role in combating oxidative stress by neutralizing free radicals. It is produced in the pineal gland and found in various organs. Melatonin's antioxidant properties are well-documented, with extensive research highlighting its ability to scavenge a wide range of reactive oxygen and nitrogen species. The primary mechanisms of melatonin's free radical scavenging activity include electron transfer and hydrogen transfer, though other mechanisms also contribute. The chemical nature of the free radical influences the relative importance of these mechanisms. Melatonin is effective against radicals such as hydroxyl (·OH), peroxyl (·OO·), and nitric oxide (·NO), but less so against superoxide (O₂·⁻) and lipoperoxyl radicals. Melatonin's ability to regenerate and its low toxicity make it a versatile and efficient antioxidant. It is widely distributed in the body and can cross cellular membranes, contributing to its effectiveness in protecting against oxidative stress. Despite some controversies regarding its efficiency against certain radicals, melatonin is generally recognized as a potent antioxidant with minimal side effects. Its role in various physiological processes, including immune function and neuroprotection, further underscores its importance in maintaining health. Overall, melatonin's diverse mechanisms and broad-spectrum antioxidant activity make it a key player in combating oxidative stress and promoting health.Melatonin, a natural antioxidant, plays a crucial role in combating oxidative stress by neutralizing free radicals. It is produced in the pineal gland and found in various organs. Melatonin's antioxidant properties are well-documented, with extensive research highlighting its ability to scavenge a wide range of reactive oxygen and nitrogen species. The primary mechanisms of melatonin's free radical scavenging activity include electron transfer and hydrogen transfer, though other mechanisms also contribute. The chemical nature of the free radical influences the relative importance of these mechanisms. Melatonin is effective against radicals such as hydroxyl (·OH), peroxyl (·OO·), and nitric oxide (·NO), but less so against superoxide (O₂·⁻) and lipoperoxyl radicals. Melatonin's ability to regenerate and its low toxicity make it a versatile and efficient antioxidant. It is widely distributed in the body and can cross cellular membranes, contributing to its effectiveness in protecting against oxidative stress. Despite some controversies regarding its efficiency against certain radicals, melatonin is generally recognized as a potent antioxidant with minimal side effects. Its role in various physiological processes, including immune function and neuroprotection, further underscores its importance in maintaining health. Overall, melatonin's diverse mechanisms and broad-spectrum antioxidant activity make it a key player in combating oxidative stress and promoting health.