Acetyl L-carnitine (ALCAR) is a derivative of the amino acid L-carnitine, which plays a critical role in cellular energy metabolism, particularly in the transport of fatty acids into mitochondria for β-oxidation. Its use in cardiovascular disease (CVD) has some scientific validation. Several clinical trials and meta-analyses have investigated carnitine and its derivatives for cardiovascular support, especially in patients with chronic heart failure, angina, and after acute myocardial infarction (MI).

Evidence suggests that supplementation with L-carnitine or acetyl L-carnitine may improve exercise tolerance, reduce symptoms of angina, and decrease mortality after MI. A 2013 meta-analysis in the journal Mayo Clinic Proceedings (DiNicolantonio et al.) found that L-carnitine supplementation in post-MI patients reduced all-cause mortality, ventricular arrhythmias, and angina symptoms. While most studies used L-carnitine, acetyl L-carnitine is believed to have similar, if not slightly enhanced, bioavailability and neuroprotective properties.

Mechanistically, ALCAR may benefit cardiovascular health by improving mitochondrial function, reducing oxidative stress, and supporting endothelial function. However, the evidence is mixed, and large-scale, high-quality randomized controlled trials specifically investigating acetyl L-carnitine in cardiovascular disease populations are limited. As such, while there is scientific rationale and some clinical data supporting its use, the evidence is moderate (rating: 3/5) and it should not replace standard medical therapies.