l Carnitine l tartrate supplementation favorably affects biochemical markers of recovery from physical exertion in middle aged men and women ScienceDirect Targeting Skeletal Muscle Dysfunction With L Carnitine for the Treatment of Patients With Chronic Obstructive Pulmonary Disease In Vivo Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish. L carnitine Supplementation as Treatment for Cardiac Fibrosis and Heart Failure with Preserved Ejection Fraction