A choline carrier that reaches the brain efficiently. Its strongest evidence sits in damaged brains: gains in thinking, daily function and mood in dementia and after stroke. In healthy adults the evidence is thin. Short-term use is well tolerated; the unresolved question is long-term artery risk. Most positive trials were funded by companies selling it. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Trimethylamine N-oxide | <3 µmol/L | Direct readout of the main long-term safety concern |
| Homocysteine | 5-8 µmol/L | Shows whether the choline load is feeding methylation as intended |
| Estimated glomerular filtration rate | >90 mL/min/1.73 m² | Trimethylamine N-oxide is cleared by the kidneys, so filtration sets exposure |
| Thyroid-stimulating hormone | 0.5-2.0 mIU/L | One trial found suppression at 500 mg daily that was never followed up |
| Apolipoprotein B | <80 mg/dL, or <60 with existing vascular disease | Baseline artery-disease burden that any pro-atherogenic exposure would compound |
| High-sensitivity C-reactive protein | <0.5 mg/L | The proposed artery mechanism is inflammatory, so this tracks it |
| Blood pressure | <120/80 mmHg | The dominant modifiable stroke risk, against which any alpha-GPC signal is small |
| Standardised cognitive test score | No established target; track change from the individual's own baseline | Separates a real effect from expectancy |
Cadence: Full panel at baseline before starting; trimethylamine N-oxide and thyroid-stimulating hormone rechecked at 8 to 12 weeks; full panel repeated every 6 to 12 months while use continues, and once more 4 weeks after any prolonged course ends.