Acetyl-L-Carnitine (ALCAR) is the acetylated form of L-Carnitine, an amino acid with a voluminous amount of therapeutic effects, including memory enhancement and more efficient mitochondria function in mouse models. The acetylated (extra oxygen and carbon group) provides a more robust bio-availability. In other words, more carnitine reaches the blood stream from the digestive tract. High levels of carnitine are ubiquitous throughout the plant kingdom, and the compound may be ingested naturally via nuts and berries. The human dose range is 500mg to 2 g per day. 

Mitochondria are the power plants of the cell, and yield an improvement in physical aerobic capacity in most species. These mitochondria produce adenine triphosphate, a required metabolic component of muscle cells. Genetic deficiencies in these molecules will yield varying disorders, and supplementation may yield improved exercise capacity in susceptible individuals. 

In healthy individuals, the findings are less clear. The primary mechanism of therapeutic benefit is essentially improved cardiovascular function due to metabolic enhancement. In other words, the body has a larger energetic potential and this may cause a patient to exercise more frequently, leading to a decreased risk of atherosclerosis. These findings are often extrapolations of mouse models, so the results should be interpreted with caution. All in all, ALCAR is a promising molecule to supplement with a low incidence of side effects.