Acetyl-L-Carnitine

Also indexed as: Acetylcarnitine, ALC, L-Acetyl-Carnitine

What does it do?

Acetyl-L-carnitine is similar in form to the amino acid L-carnitine and also has some similar functions, such as being involved in the metabolism of food into energy.

The acetyl group that is part of acetyl-L-carnitine contributes to the production of the neurotransmitter acetylcholine, which is required for mental function. Several double-blind clinical trials suggest that acetyl-L-carnitine delays the progression of Alzheimer's disease1 2 and enhances overall performance in some people with Alzheimers disease.3 Alzheimer's research has been done with the acetyl-L-carnitine form, rather than the L-carnitine form, of this nutrient.

One double-blind trial4 has found that acetyl-L-carnitine may be helpful for people with degenerative cerebellar ataxia, a loss of muscular coordination caused by disease in the cerebellum (the hind part of the brain that controls muscle tone and balance).

Where is it found?

Acetyl-L-carnitine is a molecule that occurs naturally in the brain, liver, and kidney. It is also available as a dietary supplement.

Acetyl-L-carnitine has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating Health Concerns
3Stars

Age-related cognitive decline
2Stars

Alzheimer’s disease

Cerebellar ataxia, degenerative

Depression (for elderly people)

Down's syndrome
1Star

Amenorrhea

Male infertility

Peripheral neuropathy
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Who is likely to be deficient?

Acetyl-L-carnitine levels may decrease with advancing age. However, because it is not an essential nutrient, true deficiencies do not occur.

How much is usually taken?

Most research involving acetyl-L-carnitine has used 500 mg three times per day, though some research has used double this amount.5

Are there any side effects or interactions?

Side effects from taking acetyl-L-carnitine are uncommon, although skin rash, increased appetite, nausea, vomiting, agitation, and body odor have been reported in people taking acetyl-L-carnitine.6 7

Are there any drug interactions?
Certain medicines may interact with acetyl-L-carnitine. Refer to drug interactions for a list of those medicines.

References

1. Pettegrew JW, Klunk WE, Panchalingam K, et al. Clinical and neurochemical effects of acetyl-L-carnitine in Alzheimer’s disease. Neurobiol Aging 1995;16:1-4.

2. Sano M, Bell K, Cote L, et al. Double-blind parallel design pilot study of acetyl levocarnitine in patients with Alzheimer’s disease. Arch Neurol 1992;49:1137-41.

3. Cucinotta D, Passeri M, Ventura S, et al. Multicenter clinical placebo-controlled study with acetyl-L-carnitine (LAC) in the treatment of mildly demented elderly patients. Drug Development Res 1988;14:213-6.

4. Sorbi S, Forleo P, Fani C, Piacentini S. Double-blind, crossover, placebo-controlled clinical trial with L-acetylcarnitine in patients with degenerative cerebellar ataxia. Clin Neuropharmacol 2000;23:114-8.

5. No authors listed. Acetyl-L-Carnitine. Altern Med Rev 1999;4:438–41 [review].

6. Thal LJ, Carta A, Clarke WR, et al. A 1-year multicenter placebo-controlled study of acetyl-L-carnitine in patients with Alzheimer’s disease. Neurology 1996;47:705–11.

7. Rai G, Wright G, Scott L, et al. Double-blind, placebo controlled study of acetyl-L-carnitine in patients with Alzheimer’s dementia. Curr Med Res Opin 1990;11:638–47.