Pure Lab Vitamins Melatonin - 10 mg - Melatonin is a hormone secreted by the pineal gland upon the shift from light to darkness, making us sleepy. It suppresses the release of noradrenaline, dopamine, and cortisol. All three of these stimulating chemical messengers can interfere with a good night’s sleep. Healthy melatonin levels are instrumental in feeling refreshed upon waking; they even support the immune system. Pure Lab Vitamins Slow Release Melatonin provides 10 milligrams of melatonin per sustained-release capsule, for longer lasting benefits.