Neurotransmitter in the central nervous system whic has an influence on anxiety and relaxation.

Stressful agent:
"Stressful agent" all factors, internal or external, likely to generate a state of stress on an individual.

Tendency of an organism to retain or to regain its equilibrium, threatened by the action of physical or chemical factors, thanks to the mechanism of regulating systems.

Recognises substances introducing a specific affinity on the nervous system.

Falling asleep phase:
Sleep is divided into several successive cycles of about 90 minutes. Every cycle consists of 3 distinct phases:
     - a falling asleep phase also called " calm awakening ", during which the cerebral waves decelerate to allow us to fall asleep;
     - a stage of slow sleep, representing more than 2/3 of a cycle of sleep
     - and a stage of paradoxical sleep.
A psychological stress can cause sleeping difficulties. It is generally one of the first reasons of insomnia registered by the individuals suffering from sleep disturbances.

Use of plants or substances of plant origin for therapeutic aims.

In a clinical study, the placebo is the equivalent of a decoy. It must be in every way identical to the studied substance dose (example: in form of capsules of the same form, even colour, the same smell) but containing no active molecule.

All the constituents of a plant which provides functional properties.