However , carnitine supplementation at dosages of ≤ 1000 mg/day ( p = 0.035 ) or equal to 2000 mg/day ( p = 0.013 ) result ed in significant reduction in ALT level , while doses more than 2000 mg/day did not change ALT  significantly .
Carnitine exerts its reducing effect on serum ALT and AST levels only when these aminotransferases are raised or when the duration of supplementation lasts at least 3 months .
Results of the current meta- analysis showed that carnitine supplementation can decrease serum AST and ALT levels significantly , especially when supplementation lasts 3 months or more in patients with elevated serum aminotransferase levels
L-carnitine supplementation in patients with cystic acne on isotretinoin therapy.
BACKGROUND Patients with cystic acne ( CA ) on Isotretinoin ( Iso ) therapy  might present muscular symptoms as side effect of the drug . Myalgia , weakness , hypotension are also some of the main characteristics of carnitine ( car ) deficiency . METHODS Two hundred and thirty ( N = 230 ) patients with CA were treated with Isotretinoin ( 0.5 mg/kg per 24 h ) . All the patients were requested to visit our out-patient department at the onset of muscular symptoms . Laboratory tests including car ( total , free , acylcarnitine ) were determined in blood and urine before treatment , at the onset of muscular symptoms and after the end of a 45 day study . Fifty percent of the patients with muscular involvement received L-carnitine ( 100 mg/kg per 24 h per os ) ( group C ) and 50 % placebo ( group P ) . RESULTS Their laboratory tests showed the well known increases of their liver enzymes and lipids , whereas car blood levels were remarkably decreased at the onset of their muscular symptoms and or at the end of the study . Their supplementation with L-car , in patients of group C ( N = 20 ) without Iso discontinuation or reduction , result ed in the disappearance of their muscular symptoms within 5 - 6 days and normalisation not only of the increased levels of their liver enzymes but also those of car , at the 45 day of their therapy . Additionally , the patients who received placebo ( group P , N = 20 ) continued complaining for mualgias . The rest of the patients ( group A , N = 190 ) did not experience any muscular symptoms , their laboratory tests showed elevation of liver enzymes and lipids and a decrease in car levels in the blood whereas a remarkable increase of car excretion was determined in their urine . CONCLUSIONS Iso therapy decreases car blood levels in patients with CA . L-car supplementation might treat liver and muscular side effects of the drug . These hopeful preliminary results need further investigation
However , carnitine supplementation at dosages of ≤ 1000 mg/day ( p = 0.035 ) or equal to 2000 mg/day ( p = 0.013 ) result ed in significant reduction in ALT level , while doses more than 2000 mg/day did not change ALT  significantly .
Carnitine exerts its reducing effect on serum ALT and AST levels only when these aminotransferases are raised or when the duration of supplementation lasts at least 3 months .
Results of the current meta- analysis showed that carnitine supplementation can decrease serum AST and ALT levels significantly , especially when supplementation lasts 3 months or more in patients with elevated serum aminotransferase levels