L-carnitine (Levocarnitine)

As well as supporting energy production, L-carnitine may help some other functions in the body, such as maintaining general brain function and reducing the risk of certain disorders (3). L-carnitine is a conditionally essential nutrient, meaning that the body can generally make enough of it, but, in some cases, a person may have to get the compound from food or oral supplements if they cannot make enough. The liver and kidneys create L-carnitine from the amino acids lysine and methionine. The kidneys can also store L-carnitine for later use and eliminate the excess through the urine stream. There are distinct types of Carnitine. L-carnitine is a more usual form of carnitine, present in the body and many supplements. Other forms of carnitine include Acetyl L-carnitine: This form, sometimes known as ALCAR, also plays a role in metabolism. It possesses neuroprotective properties that may help protect the nervous system. D-carnitine: This type is the optical isomer (mirror image) of L-carnitine. It is toxic to the body, as it may inhibit the absorption of other forms of carnitine. L-carnitine L-tartrate: Athletes may use this type in the form of sports supplements. Research suggests that it may be useful in minimizing muscle soreness and aiding recovery (4). Propionyl-L-carnitine: This form displays pain relieving and antirheumatic properties, and it may benefit heart health.