L-Theanine vs Magnesium Glycinate

Mechanism

L-Theanine (gamma-glutamylethylamide) crosses the blood-brain barrier via the large neutral amino acid transporter. It increases alpha brain wave activity (8-13 Hz, associated with relaxed alertness), enhances GABA, serotonin, and dopamine levels in the brain, and antagonizes glutamate excitotoxicity by blocking glutamate binding at AMPA, kainate, and NMDA receptors. It also increases BDNF and NGF expression, supporting neuroplasticity. The combination of glutamate antagonism and GABA/serotonin enhancement produces anxiolysis without sedation — a 'calm focus' state.

Standard Dosing

100-200mg daily (or as needed for acute anxiety/focus)

Timing

Flexible: morning for calm focus (stack with caffeine), before stressful events, or evening for relaxation/sleep onset. Onset: 30-60 minutes oral, 15-20 min sublingual.

Cycle Duration

ongoing or as needed

Side Effects

• Headache (rare)
• GI discomfort (rare)
• Dizziness at very high doses
• Generally extremely well-tolerated

Contraindications

• Very few — one of the safest supplements available. Caution in severe hypotension.

Best Stacking Partners

Mechanism

Magnesium is a cofactor for >600 enzymatic reactions including all ATP-dependent reactions (Mg-ATP is the true substrate), DNA/RNA polymerases, and ion channel regulation. Magnesium glycinate chelate provides highly bioavailable elemental magnesium bound to glycine. The glycine moiety itself is an inhibitory neurotransmitter (glycine receptors) and NMDA receptor co-agonist at the glycine binding site. The chelated form minimizes the osmotic laxative effect of ionic magnesium salts. Magnesium regulates NMDA receptor gating (voltage-dependent Mg2+ block), GABA-A receptor potentiation, HPA axis modulation, and parathyroid hormone secretion.

Standard Dosing

200-400mg elemental magnesium daily

Timing

Evening/bedtime (promotes relaxation and sleep quality). Can split AM/PM.

Cycle Duration

ongoing

Side Effects

• Drowsiness
• Mild GI discomfort
• Loose stools (less than other Mg forms)
• Hypotension at very high doses

Contraindications

• Severe renal insufficiency (impaired Mg excretion — risk of hypermagnesemia)
• Myasthenia gravis (Mg can worsen neuromuscular junction blockade)
• Heart block (Mg slows AV conduction)

Best Stacking Partners