Copper (as Copper Bisglycinate) vs Magnesium L-Threonate

Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.

Copper (as Copper Bisglycinate)Magnesium L-Threonate
CategoryMineralsMinerals
Standard Dose1-2mg elemental copper daily (when supplementing zinc >25mg)1000-2000mg magnesium L-threonate daily (providing ~144mg elemental Mg per 2000mg)
TimingWith food. Separate from zinc by 2+ hours for optimal absorption of both.Split dose: 1 capsule morning, 2 capsules before bed (or per product label). Evening dose supports sleep and overnight memory consolidation.
Cycle Durationongoing when zinc supplementation is ongoingongoing
Evidence Levelstrong_humanmoderate_human

Mechanism

Copper is a cofactor for critical cuproenzymes: cytochrome c oxidase (Complex IV, mitochondrial respiration), Cu/Zn-SOD (superoxide dismutation), ceruloplasmin (ferroxidase — converts Fe2+ to Fe3+ for transferrin loading; essential for iron metabolism), lysyl oxidase (collagen and elastin cross-linking), dopamine beta-hydroxylase (dopamine to norepinephrine conversion), tyrosinase (melanin synthesis), and peptidyl-glycine alpha-amidating monooxygenase (neuropeptide processing). Copper is transported by ATP7A/B (Menkes/Wilson proteins) and regulated by metallothionein and glutathione.

Standard Dosing

1-2mg elemental copper daily (when supplementing zinc >25mg)

Timing

With food. Separate from zinc by 2+ hours for optimal absorption of both.

Cycle Duration

ongoing when zinc supplementation is ongoing

Side Effects

  • Nausea (on empty stomach)
  • GI upset
  • Metallic taste
  • Copper toxicity at high doses (hepatotoxicity, hemolytic anemia)

Contraindications

  • Wilson's disease (genetic copper overload)
  • Copper storage disorders
  • Copper excess states

Best Stacking Partners

Zinc (1:15 Cu:Zn ratio)Vitamin C (low dose — high-dose C reduces Cu absorption)Iron

Mechanism

Magnesium L-threonate (Magtein) was specifically developed by MIT researchers to cross the blood-brain barrier efficiently. L-threonate, a metabolite of vitamin C, acts as a carrier to increase brain magnesium concentration by ~15% (compared to negligible CNS penetration from other Mg forms). Elevated brain Mg2+ enhances NMDA receptor signaling fidelity, increases synaptic density in the hippocampus and prefrontal cortex, promotes BDNF expression, and enhances both short-term and long-term memory via potentiation of pre-synaptic release probability at hippocampal CA3-CA1 synapses.

Standard Dosing

1000-2000mg magnesium L-threonate daily (providing ~144mg elemental Mg per 2000mg)

Timing

Split dose: 1 capsule morning, 2 capsules before bed (or per product label). Evening dose supports sleep and overnight memory consolidation.

Cycle Duration

ongoing

Side Effects

  • Drowsiness
  • Headache (initial)
  • Mild GI discomfort
  • Cost (significantly more expensive than other Mg forms)

Contraindications

  • Severe renal insufficiency
  • Myasthenia gravis

Best Stacking Partners

Lion's ManePhosphatidylserineOmega-3 (DHA)Bacopa Monnieri

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