Magnesium Glycinate vs Potassium (Citrate)

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

Mechanism

Potassium is the principal intracellular cation, maintaining resting membrane potential (-70 to -90mV) via the Na+/K+-ATPase pump (3 Na+ out, 2 K+ in per ATP). It is essential for: cardiac rhythmicity (phase 3 repolarization of cardiac action potential), skeletal muscle contraction, nerve impulse transmission, acid-base balance (exchanged for H+ in renal tubules), blood pressure regulation (promotes natriuresis via renal sodium excretion), and insulin secretion. Citrate form provides alkalinizing anion that inhibits calcium oxalate and uric acid kidney stone formation.

Standard Dosing

99-200mg per capsule (regulatory limit in US); dietary target 3500-4700mg/day total

Timing

With meals, divided throughout the day. Slow-release forms preferred for higher doses.

Cycle Duration

ongoing

Side Effects

• GI irritation/ulceration (non-microencapsulated forms)
• Nausea
• Diarrhea
• Hyperkalemia (dangerous — cardiac arrhythmias)

Contraindications

• Hyperkalemia
• Renal insufficiency (impaired K+ excretion)
• Addison's disease (aldosterone deficiency)
• Concurrent ACE inhibitor/ARB + potassium-sparing diuretic

Best Stacking Partners