Why Does Melatonin Cause Increased Mental Stimulation, Vivid Dreams

Q: Why does melatonin cause increased mental stimulation, vivid dreams, nightmares, etc?

A: There are many reasons. Generally speaking, impure products, especially those that come in a pill form contain binders and fillers that the brain is sensitive to. These can cause nightmares. Those who are very weak in advance stages of AFS can also have paradoxical reaction to many natural compounds, and melatonin is one of them.