Endothelial dysfunction is common in both Long COVID and ME CFS and has been linked to symptoms like fatigue, chest pain, and brain fog. Research suggests that certain supplementslike L arginine, CoQ10, curcumin, and L Carnitine: Benefits, side effects, and dosage L CARNITINE 1 GM 5 ML ( L CARNITINE ) 5 X 5 ML IV USE AMPOULES Gplc Glycine Propionyl l carnitine Nutritional Supplement Molecule Stock Illustration 275560898 Shutterstock