Carnitine, Free Unit Converter

Free carnitine is the unbound, active form of carnitine circulating in your blood. It is a water-soluble compound derived from the amino acids lysine and methionine.

Carnitine in the blood exists in two forms: free (unconjugated) and esterified (bound to acyl groups). Free carnitine is the fraction available for its primary job of transporting long-chain fatty acids into mitochondria, where they are burned for energy.

The ratio of esterified to free carnitine (E/F ratio) is also clinically important. A ratio greater than 0.4 may suggest carnitine depletion or a fatty acid oxidation disorder.

About 75% of carnitine in omnivores comes from dietary sources (primarily red meat, dairy, and fish), while the remaining 25% is synthesized in the liver and kidneys from the amino acids lysine and methionine, requiring iron, vitamin C, vitamin B6, and niacin as cofactors.