Mechanisms of Action
Neurotransmitter
A chemical messenger transmitting signals between nerve cells in the brain and body.
Neurotransmitters are chemical messengers released from presynaptic neurons that bind to receptors on postsynaptic neurons, muscle cells, or glands to transmit signals. Key neurotransmitters relevant to supplement research include serotonin (mood, sleep precursor), GABA (calming, sleep), dopamine (motivation, reward), acetylcholine (memory, cognition), and norepinephrine (alertness, stress response). Many supplements act as neurotransmitter precursors (tryptophan → serotonin, tyrosine → dopamine) or modulators (L-theanine increases GABA and serotonin, magnesium modulates NMDA receptors).