Compound · alcar
T1Supplement

Acetyl-L-Carnitine (ALCAR)

Acetylated form of L-carnitine that crosses the blood-brain barrier. Shuttles long-chain fatty acids across the inner mitochondrial membrane via the carnitine palmitoyltransferase (CPT) system for beta-oxidation. The acetyl group donates to acetyl-CoA pools, supporting both mitochondrial energy production and acetylcholine synthesis. Neuroprotective effects mediated through upregulation of nerve growth factor (NGF) receptors.

Half-life
~4.2 hours
Bioavailability
~16% (oral)
Route
oral
Evidence tier
T1 — Multiple RCTs
Optimization pillars
cellular-health · recovery
References
2 peer-reviewed
Dose ranges

Three tiers ordered by aggressiveness. Tier chips on every OPTIMIZE intervention let you filter the catalog by your evidence tolerance.

conservative
500 mg/day
Baseline mitochondrial and cognitive support
moderate
1000–1500 mg/day
Standard nootropic and fat metabolism dose
aggressive
2000–3000 mg/day
Clinical neuroprotection protocols
Monitoring
  • thyroid-panel
  • homocysteine
Contraindications
  • hypothyroidism-uncontrolled
  • seizure-disorder
References
  • PMID:17658628Acetyl-L-carnitine: a review of its pharmacology and clinical useInt J Clin Pharmacol Ther, 2007
  • PMID:12213546A meta-analysis of acetyl-L-carnitine for cognitive declinePsychogeriatrics, 2002
Notes

ALCAR is the only form of carnitine worth discussing for cognitive applications. The acetyl group is the differentiator — it crosses the blood-brain barrier where standard L-carnitine cannot. Dual mechanism. Mitochondrial fatty acid transport on one side. Acetylcholine precursor support on the other. The meta-analyses for mild cognitive impairment are positive. The exercise performance data is modest. Where ALCAR earns its place is in the mitochondrial stack alongside CoQ10 and PQQ. Three compounds targeting three different bottlenecks in the same organelle.

This is not medical advice

Discuss with a licensed clinician before starting, stopping, or changing any compound. This page documents what the research literature describes — it is not a prescription.

See Acetyl-L-Carnitine (ALCAR) in a protocol matched to you

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