Nutritional Frontiers Sleep Time 60 capsDescription The Sleep Time formulation, to be taken 1 hour before bed, is designed to improve problems with sleep.* Sleep Time was formulated to help support the neurotransmitters dopamine and serotonin, which have a role with sleep cycles and anxiety.* Neurotransmitters are natural chemical messengers in the nervous system that send signals from one nerve cell across a synapse to another nerve cell or target organ. Serotonin plays a role in sleep,