L-carnitine is a naturally occurring amino acid that plays a vital role in energy metabolism by transporting fatty acids into the mitochondria for cellular energy production . It promotes the efficient utilization of fatty acids and assists in the use of fat as an energy source during exercise and potentially preserves glycogen stores for energy and muscle function and may therefore increase endurance and reduce fatigue.
It can be obtained from food sources or taken as a dietary supplement . There are different forms of carnitine , including Acetyl L-Carnitine , which has an additional acetyl group that allows it to easily pass through the brain barrier . It is therefore primarily recognized for its potential benefits for the brain , cognitive function , memory and mood enhancement, unlike l-carnitine itself.
Although acetyl l-carnitine shares most of the benefits with l-carnitine in terms of supporting energy and mitochondria , standard L-carnitine or propionyl carnitine is better for fertility for both men and women .