Introduction

Melatonin. daily. The Melatonin then returns back to Serotonin. The whole cycle of this Serotonin-Melatonin-Serotonin cycle takes about 24 hours. This hormone cycle is treated as the . body clock. This 24 hour body clock sets the body chemistry for sleeping and waking. Along with Serotonin, the Stress fighting hormone . Cortisol ................
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