Acetyl-L-carnitine (ALC) is a chemical product of the amino acid, carnitine. It is produced naturally in humans, with the greatest amounts being found in muscles, the brain, and in the testicles. ALC has been studied for its potential use in slowing, and even partially reversing, nerve and brain deterioration associated with the aging process.

Dosage Info

Dosage Range

500-2,500mg daily.

Most Common Dosage

500mg, 2 times a day.

Dosage Forms

Capsules and tablets.

Reported Uses

As part of its role in supporting mental function, ALC may improve memory, attention span, and mental performance in normal people as well as those with brain impairment. It is also instrumental in the production and release of one of the brain’s vital neurotransmitters, a substance scientists call acetylcholine. ALC may also support healthy function of the male reproductive system and improve intracellular energy transfer.

ALC has been studied for its potential use in treating a number of disorders. Some studies have demonstrated memory improvement in rats when given the combination of ALC and lipoic acid. (1) , (2) Studies suggest that ALC can slow the progression of Alzheimer’s disease. (3) , (4) , (5) Though other studies are indicating that Alzheimer’s disease patients treated for one year with ALC gain very little benefit. (6)

ALC may play a role in alcoholism. Animal studies have demonstrated that acetyl-L-carnitine may be useful in preventing damage to cells that may be caused by alcohol. (7) , (8) Another study demonstrated that acetyl-L-carnitine reduced the onset of tremors associated with alcohol withdrawal, suggesting that ALC may be useful in the treatment of alcohol dependence. (9)

Researchers have found that ALC significantly improved fatigue and was well tolerated. (10) , (11) In elderly patients, ALC has been used to treat depression and improve quality of life. (12) ALC has been used with positive results to treat deteriorations of the nervous system associated with diabetes. (13) Finally, ALC may play a beneficial role in reducing the development of cataracts (14) and has shown positive results in Peyronie’s disease. (15)

Toxicities & Precautions


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This dietary supplement is considered safe when used in accordance with proper dosing guidelines.

Side Effects

Although rare, occasional side effects reported with the use of this dietary supplement include nausea and vomiting. (16) Sleeplessness may occur if taken before bed. Tell your doctor if these side effects become severe or do not go away.

Pregnancy / Breast Feeding

This dietary supplement should not be used if you are pregnant or breast-feeding an infant without first consulting a physician.

Age Limitations

To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Since young children may have undiagnosed allergies or medical conditions, this dietary supplement should not be used in children under 10 years of age unless recommended by a physician.


  1. View Abstract: Hagen TM, Liu J, Lykkesfeldt J, Wehr CM, Ingersoll RT, Vinarsky V, et al. Feeding acetyl-L-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress. Proc Natl Acad Sci U S A. Feb2002;99(4):1870-1875.
  2. View Abstract: Liu J, Head E, Gharib AM, Yuan W, Ingersoll RT, Hagen TM, et al. Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: Partial reversal by feeding acetyl-L-carnitine and/or R-alpha -lipoic acid. Proc Natl Acad Sci U S A. Feb2002;99(4):2356-2361.
  3. View Abstract: Brooks JO 3rd, et al. Acetyl-L-carnitine Slows Decline in Younger Patients with Alzheimer’s Disease: A Reanalysis of a Double-blind, Placebo-controlled Study Using the Trilinear Approach. Int Psychogeriatr. Jun1998;10(2):193-203.
  4. View Abstract: Spagnoli A, et al. Long-term Acetyl-L-carnitine Treatment in Alzheimer’s Disease. Neurology. Nov1991;41(11):1726-32.
  5. View Abstract: Montgomery SA, Thal LJ, Amrein R. Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer’s disease. Int Clin Psychopharmacol. Mar2003;18(2):61-71.
  6. View Abstract: Mangano NG, Clementi G, Costantino G, et al. Effect of acetyl-L-carnitine on ethanol consumption and alcohol abstinence syndrome in rats. Drugs Exp Clin Res. 2000;26(1):7-12.
  7. View Abstract: Calabrese V, Scapagnini G, Catalano C, et al. Effects of acetyl-L-carnitine on the formation of fatty acid ethyl esters in brain and peripheral organs after short-term ethanol administration in rat. Neurochem Res. Feb2001;26(2):167-74.
  8. View Abstract: Sbriccoli A, Carretta D, Santarelli M, et al. An optimised procedure for prenatal ethanol exposure with determination of its effects on central nervous system connections. Brain Res Brain Res Protoc. Jan1999;3(3):264-9.
  9. View Abstract: Mangano NG, Clementi G, Costantino G, et al. Effect of acetyl-L-carnitine on ethanol consumption and alcohol abstinence syndrome in rats. Drugs Exp Clin Res. 2000;26(1):7-12.
  10. View Abstract: Vermeulen RC, Scholte HR. Exploratory open label, randomized study of acetyl- and propionylcarnitine in chronic fatigue syndrome. Psychosom Med. Mar2004;66(2):276-82.
  11. View Abstract: Tomassini V, Pozzilli C, Onesti E, et al. Comparison of the effects of acetyl L-carnitine and amantadine for the treatment of fatigue in multiple sclerosis: results of a pilot, randomised, double-blind, crossover trial. J Neurol Sci. Mar2004;218(1-2):103-8.
  12. View Abstract: Bella R, et al. Effect of Acetyl-L-carnitine on Geriatric Patients Suffering from Dysthymic Disorders. Int J Clin Pharmacol Res. 1990;10(6):355-60.
  13. View Abstract: Lowitt S, et al. Acetyl-L-carnitine Corrects the Altered Peripheral Nerve Function of Experimental Diabetes. Metabolism. May1995;44(5):677-80.
  14. View Abstract: Swamy-Mruthinti S, Carter AL. Acetyl- L -carnitine decreases glycation of lens proteins: in vitro studies. Exp Eye Res. Jul1999;69(1):109-15.
  15. View Abstract: Biagiotti G, Cavallini G. Acetyl-L-carnitine vs tamoxifen in the oral therapy of Peyronie’s disease: a preliminary report. BJU Int. Jul2001;88(1):63-7.
  16. View Abstract: Rai G, Wright G, Scott L. Double-blind, placebo controlled study of acetyl-l-carnitine in patients with Alzheimer’s dementia. Curr Med Res Opin. 1990;11(10):638-647.