Inhibitory Neurotransmitters
Serotonin is made from tryptophan and 5-HTP and works to keep all the neurotransmitters in balance. It also prevents over-stimulation. Low levels play a role in many conditions including depression, anxiousness, sleep problems, uncontrolled appetite, migraine headaches and premenstrual complaints.

GABA levels go up when the excitatory neurotransmitters are too high, as a compensatory reaction. High levels of GABA are often associated with sleeping problems, nervousness and hyperactivity.

Glycine helps dampen the effects of elevated excitatory neurotransmitters and can be high in people who are anxious, depressed or having stress-related symptoms.

Taurine is important in preventing the harmful effects of excess glutamate and maintaining fluid balance. Optimal taurine levels are important for proper heart function, healthy sleep and promoting calmness.

Excitatory Neurotransmitters
Epinephrine, also known as adrenaline, is important for motivation, energy, and mental focus. Low levels can result in fatigue, lack of focus and difficulty losing weight, while those with high levels often have sleeping problems, anxiousness and ADHD.

Norepinephrine is also called noradrenaline. High levels are linked to feelings of anxiousness, stress, hyperactivity and high blood pressure. Low levels are linked to lack of energy, focus and motivation.

Dopamine is responsible for feelings of pleasure and satisfaction and is involved in muscle control and function. Low levels are associated with addictions and cravings while high levels have been observed with poor GI function and children with attention disorders.

Glutamate is necessary for learning and memory. Excessive amounts can result in anxiousness and depression while low levels are associated with tiredness and poor brain activity.

PEA is important for focus and concentration. People with "mind racing," sleep problems and anxiousness often have high PEA while those with low levels tend to have difficulty thinking clearly and paying attention.

Histamine helps control the sleep-wake cycle. High levels are associated with allergic responses and sleep problems, whereas low levels are associated with fatigue.

Glutamine is made into GABA and Glutamate. Optimal glutamine levels are also important for intestinal function. High levels are considered a signal of an overall imbalance in the neurotransmitter system.