I've read that the dietary supplement acetyl-L-carnitine may reduce fatigue in multiple sclerosis. Is this true?

Answer From Iris Marin Collazo, M.D.

Currently, there isn't enough evidence to know if acetyl-L-carnitine helps improve fatigue associated with multiple sclerosis (MS). More studies are needed.

Acetyl-L-carnitine is a form of L-carnitine, an amino acid found in nearly all cells of the body. L-carnitine plays a critical role in turning fat into energy. In addition, it increases the activity of certain nerve cells in the central nervous system.

Fatigue is reported in about 80% of people with multiple sclerosis. The cause of the fatigue isn't well understood. However, some types of MS-related fatigue may happen due to pain, depression, waking up at night because of bladder problems, or the effort it takes to perform daily duties. Other factors also can contribute to fatigue in people with MS. They include obesity, being sedentary, dietary habits, not enough vitamin levels in the body and medicine side effects.

Some studies have suggested that acetyl-L-carnitine supplements could ease MS-related fatigue in people with low blood levels of L-carnitine.

A small study found that acetyl-L-carnitine works better than certain medicines used to treat fatigue, such as amantadine (Gocovri, Osmolex ER). But additional studies haven't had conclusive results. They've shown a possible benefit for MS-related fatigue that wasn't statistically significant.

Acetyl-L-carnitine generally has few or mild side effects, but it can interfere with blood-thinning medicines and other drugs. Talk with your health care provider before taking acetyl-L-carnitine or any other supplement.


Iris Marin Collazo, M.D.

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Dec. 02, 2022 See more Expert Answers