Required cofactor for COMT enzyme activity — without magnesium, COMT cannot efficiently clear catecholamines (dopamine, norepinephrine), leaving the nervous system overstimulated at night. Magnesium also modulates NMDA glutamate receptors, reducing excitatory signaling and supporting GABAergic tone for sleep onset. Magnesium glycinate offers superior bioavailability over oxide or citrate and provides calming glycine. Supports over 300 enzymatic reactions.