Introduction
Carnitine is a nutrient in the body that turns fat into energy. It is found in meat, dairy, and bread. Carnitine has been used to improve heart health, ease fatigue, and promote fitness. It can be taken as a pill or powder. It can also be injected into the bloodstream by a healthcare provider.
Dosages
1,000 milligrams 1 to 3 times daily.
What Research Shows
Likely Effective
- Chronic heart failure—likely to ease symptoms and improve heart function E1
- Depression—likely to reduce symptoms G1
- Diabetes—likely help control blood glucose H1-H2
- Intermittent Claudication—likely to improve walking ability M1-M2
- Obesity—likely to promote weight loss P1
- Osteoarthritis—likely to ease pain Q1
- Peripheral neuropathic pain—likely to provide small reductions in pain R1-R2
May Be Effective
- Brain ischemia—may reduce symptoms C1
- Hyperthyroidism—may ease fatigue L1
May Not Be Effective
- Fragile X syndrome—may not improve intellectual function or hyperactive behavior in childrenI1
- Multiple sclerosis—may not ease fatigue O1
Unlikely to Be Effective
- Cancer-related fatigue—unlikely to ease fatigue D1
- Hemodialysis—unlikely to ease symptoms or improve quality of life J1
- Kidney disease—unlikely to lower total cholesterol N1-N2
Not Enough Data to Assess
- Attention deficit hyperactivity disorder B1
- Cognitive function F1
- Hepatic encephalopathy K1
- Valporic acid overdose S1
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Safety Notes
It is likely safe to take carnitine in small doses for a short time. Not enough studies have been done to say whether it is safe to take for a long period. It is also not known whether it is safe to take by women who are pregnant or breastfeeding.
Interactions
Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.
References
REFA Acute Myocardial Infarction
REFA1 DiNicolantonio JJ, Lavie CJ, et al. L-carnitine in the secondary prevention of cardiovascular disease: systematic review and meta-analysis. Mayo Clin Proc. 2013 Jun;88(6):544-551.
REFB Attention Deficit Hyperactivity Disorder
REFB1 Sarris J, Kean J, et al. Complementary medicines (herbal and nutritional products) in the treatment of Attention Deficit Hyperactivity Disorder (ADHD): a systematic review of the evidence. Complement Ther Med. 2011 Aug;19(4):216-227.
REFC Brain Ischemia
REFC1 Fedotova AV, Mironova OP, et al. [L-carnitine treatment patients with chronic cerebral ischemia]. Zh Nevrol Psikhiatr Im S S Korsakova. 2013;113(5):48-53.
REFD Cancer-Related Fatigue
REFD1 Marx W, Teleni L, et al. Efficacy and Effectiveness of Carnitine Supplementation for Cancer-Related Fatigue: A Systematic Literature Review and Meta-Analysis. Nutrients. 2017 Nov 7;9(11). pii: E1224.
REFE E. Chronic Heart Failure
REFE1 Song X, Qu H, et al. Efficacy and Safety of L-Carnitine Treatment for Chronic Heart Failure: A Meta-Analysis or Randomized Controlled Trials. Biomed Res Int. 2017:6274854.
REFF F. Cognitive Function
REFF1 Chen N, Yang M, et al. L-carnitine for cognitive enhancement in people without cognitive impairment. Cochrane Database Syst Rev. 2017 Mar 26;3:CD009374.
REFG G. Depression
REFG1 Vernoese N, Stubbs B, et al. Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis. Psychosom Med. 2018;80(2):154-159.
REFH H. Diabetes
REFH1 Vidal-Casariego A, Burgo-Peláez R, et al. Metabolic effects of L-carnitine on type 2 diabetes mellitus: systematic review and meta-analysis. Exp Clin Endocrinol Diabetes. 2013;121(4):234-238.
REFH2 Xu Y, Jiang W, et al. L-carnitine treatment of insulin resistance: A systematic review and meta-analysis. Adv Clin Exp Med. 2017 Mar-Apr;26(2):333-338.
REFI Fragile X Syndrome
REFI1 Rueda JR, Guillén V, et al. L-acetylcarnitine for treating fragile X syndrome. Cochrane Database Syst Rev. 2015 May 19;(5):CD010012.
REFJ J. Hemodialysis
REFJ1 Yang SK, Xiao L, et al. Effect of L-carnitine therapy on patients in maintenance hemodialysis: a systematic review and meta-analysis. J Nephrol. 2014 Jun;27(3):317-329.
REFK K. Hepatic Encephalopathy
REFK1 Martí-Carvajal AJ, Gluud C, et al. Acetyl-L-carnitine for patients with hepatic encephalopathy. Cochrane Database Syst Rev. 2019;1:CD011451.
REFL L. Hyperthyroidism
REFL1 An JH, Kim YJ, et al. L-carnitine supplementation for the management of fatigue in patients with hyperthyroidism on levothyroxine treatment: a randomized, double-blind placebo-controlled trial. Enocr J. 2016;63(10):885-895.
REFM M. Intermittent Claudication
REFM1 Delaney CL, Spark JI, et al. A systematic review to evaluate the effectiveness of carnitine supplementation in improving walking performance among individuals with intermittent claudication. Atherosclerosis. 2013 Jul;229(1):1-9.
REFM2 Brass EP, Koster D, et al. A systematic review and meta-analysis of propionyl-L-carnitine effects on exercise performance in patients with claudication. Vasc Med. 2013 Feb;18(1):3-12.
REFN N. Kidney Disease
REFN1 Huang H, Song L, et al. Influence of L-carnitine supplementation on serum lipid profile in hemodialysis patients: a systematic review and meta-analysis. Kidney Blood Press Res. 2013;38(1):31-41.
REFN2 Chen Y, Abbate M, et al. L-Carnitine supplementation for adults with end-stage kidney disease requiring maintenance hemodialysis: a systematic review and meta-analysis. Am J Clin Nutr. 2014;99(2):408-422.
REFO O. Multiple Sclerosis
REFO1 Tejani AM, Wasdell M, et al. Carnitine for fatigue in multiple sclerosis. Cochrane Database Syst Rev. 2012 May 16;(5):CD007280.
REFP P. Obesity
REFP1 Pooyandjoo M, Nouhi M, et al. The effect of (L-)carnitine on weight loss in adults: a systematic review and meta-analysis of randomized controlled trials. Obese Rev. 2016;17(10):970-976.
REFQ Q. Osteoarthritis
REFQ1 Liu X, Machado GC, et al. Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis. Br J Sports Med. 2018;52(3):167-175.
REFR R. Peripheral Neuropathic Pain
REFR1 Li S, Li Q, at al. Acetyl-L-carnitine in the treatment of peripheral neuropathic pain: a systematic review and meta-analysis of randomized controlled trials. PLoS One. 2015;10(3):e0119479.
REFR2 Brami C, Bao T, et al. Natural products and complementary therapies for chemotherapy-induced peripheral neuropathy: A systematic review. Crit Rev Oncol Hematol. 2016 Feb;98:325-334.
REFS S. Valproic Acid Overdose
REFS1 Perrott J, Murphy NG, et al. L-carnitine for acute valproic acid overdose: a systematic review of published cases. Ann Pharmacother. 2010 Jul-Aug;44(7-8):1287-1293.