GlycinevsMagnesium L-Threonate

Glycine acts as an inhibitory neurotransmitter by binding to strychnine-sensitive glycine receptors (GlyR) in the brainstem, spinal cord, and retina, hyperpolarizing neurons via chloride influx. It also serves as a mandatory co-agonist at the glycine-binding site (NR1 subunit) of NMDA glutamate receptors — without glycine binding, NMDA receptors cannot open their ion channel even when glutamate is present. This dual role means glycine both calms neural activity (sleep, anti-anxiety via GlyR) and supports excitatory learning processes (NMDA-dependent LTP and memory consolidation). Glycine lowers core body temperature at night by promoting peripheral vasodilation through nitric oxide, which improves sleep onset. It is a precursor for glutathione synthesis and modulates the glycinergic system in the suprachiasmatic nucleus.

The L-threonate carrier forms stable complexes with magnesium and transports it across the blood-brain barrier via specific transporters more effectively than inorganic magnesium salts or other chelated forms. Once in the brain, magnesium acts as a voltage-dependent blocker of the NMDA receptor channel at the physiological magnesium binding site within the ion pore, preventing excessive calcium influx and glutamate-mediated excitotoxicity. Magnesium also serves as a cofactor for over 300 enzymes including those involved in neurotransmitter synthesis (tyrosine hydroxylase, glutamic acid decarboxylase), ATP production (creatine kinase, pyruvate kinase), and DNA/RNA polymerase. Elevated brain magnesium enhances synaptic density and plasticity in the hippocampus and prefrontal cortex, likely through CREB-mediated gene expression and increased density of postsynaptic AMPA receptors.