Magnesium L-threonate is a dietary supplement form of magnesium built to reach the brain more easily, promoted mainly for memory, sleep and long-term brain health. A few small, short, mostly company-funded studies show modest gains in thinking and memory scores; sleep results are weaker and mood results mostly flat. Risks look small, mainly magnesium building up with reduced kidney function. Its added value over ordinary magnesium remains uncertain. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Serum magnesium | ≥0.85 mmol/L | Safety check: flags excess, or deficiency that changes use |
| Red-blood-cell magnesium | About 4.0–6.8 mg/dL, varying by laboratory | Safety check: low values change use |
| Serum creatinine and eGFR | Creatinine about 0.6–1.3 mg/dL; eGFR: track change from own baseline | Safety check: kidneys clear magnesium; decline stops or changes use |
Cadence: Baseline before starting; check at 6 weeks, full review at 12 weeks, then every 6–12 months. Kidney function and serum magnesium at 12 weeks, then annually; sooner with kidney disease, interacting drugs or symptoms such as weakness.