Acetyl L-Carnitine

Acetyl-L-Carnitine (ALCAR) is the acetylated ester of L-carnitine that crosses the blood-brain barrier via the carnitine transporter, unlike standard L-carnitine which is largely excluded from the CNS. Within neurons, ALCAR serves dual functions: as a mitochondrial shuttle transporting long-chain fatty acids across the inner mitochondrial membrane for beta-oxidation, and as a direct donor of acetyl groups for acetylcholine synthesis via choline acetyltransferase — making it uniquely relevant for cholinergic neurotransmission. ALCAR additionally supports the biosynthesis of phospholipid membranes, stimulates NGF production, and attenuates oxidative damage to neuronal mitochondria. Meta-analyses of randomised trials confirm ALCAR at 1,500–3,000 mg/day significantly improves cognitive function in mild cognitive impairment, reduces neuropathic pain, and attenuates depression in older adults.