acetylLcarnitine

Acetyl-L-carnitine, commonly abbreviated ALCAR, is an acetyl ester of L-carnitine. It is a naturally occurring compound in human tissues and is available as a dietary supplement. In the body, ALCAR participates in energy metabolism and may influence brain function.

Biochemical role includes participation in mitochondrial energy production. L-carnitine shuttles long-chain fatty acids into mitochondria for beta-oxidation, and the acetyl group in ALCAR can donate acetyl units and help transport acetyl-CoA. In the brain, ALCAR may cross the blood-brain barrier and contribute to acetylcholine synthesis and mitochondrial support, though the exact mechanisms are not fully understood.

Clinical evidence for its use is mixed. ALCAR is marketed for age-related cognitive decline, peripheral neuropathy, mood disorders, and general energy. Some small studies suggest modest cognitive or mood benefits in older adults or individuals with mild cognitive impairment, but results are inconsistent and higher-quality trials are needed. There is also limited and inconclusive evidence for benefits in diabetic neuropathy or nerve pain.

Safety and dosing considerations include typical supplemental doses of 500 to 2,000 mg per day, taken in one or split doses. ALCAR is generally well tolerated; possible adverse effects include gastrointestinal upset, headache, and restlessness. A rare fishy odor can occur with carnitine derivatives. Individuals should consult a healthcare provider before use, especially during pregnancy or nursing, or if there are seizure disorders, thyroid conditions, or other medications involved.

Quality and regulation vary in the dietary supplement market, and ALCAR should not be considered a substitute for medical treatment or prescribed therapies.