Also indexed as: ALA, Lipoic Acid, Thioctic Acid
Alpha lipoic acid (ALA) is a vitamin-like
antioxidant, sometimes referred to as the “universal antioxidant” because it
is soluble in both fat and water.1
ALA is manufactured in the body and is found in some foods, particularly liver and yeast.
Where is it found?
The body makes small amounts of alpha lipoic acid. There is only limited knowledge about
the food sources of this nutrient. However, foods that contain mitochondria (a specialized
component of cells), such as red meats, are
believed to provide the most alpha lipoic acid. Supplements are also available.
Alpha lipoic acid has been
used in connection with the following conditions (refer to the
individual health concern for complete information):
Who is likely to be deficient?
Although alpha lipoic acid was thought to be a vitamin when it was first discovered,
subsequent research determined that it is created in the human body—and thus is not an
essential nutrient. For this reason, deficiencies of alpha lipoic acid are not known to occur
How much is usually taken?
The amount of alpha lipoic acid used in research to improve diabetic neuropathies is 800 mg
per day and 150 mg per day for glaucoma.
However, much lower amounts, such as 20–50 mg per day, are recommended by some doctors
for general antioxidant protection, although
there is no clear evidence that such general use has any benefit.
Are there any side effects or interactions?
Side effects with alpha lipoic acid are rare but can include skin rash and the potential of
hypoglycemia in diabetic patients. People who
may be deficient in vitamin B1 (such as
alcoholics) should take vitamin B1 along with alpha lipoic acid supplements. Chronic
administration of alpha lipoic acid in animals has interfered with the actions of the vitamin,
biotin. Whether this has significance for
humans remains unknown.2
At the time of writing, there were no well-known drug interactions
with alpha lipoic acid.
1. Kagan V, Khan S, Swanson C, et al. Antioxidant action of thioctic acid
and dihydrolipoic acid. Free Radic Biol Med 1990;9S:15.
2. Zempleni J, Trusty TA, Mock DM. Lipoic acid reduces the activities of
biotin-dependent carboxylases in rat liver. J Nutr 1997;127:1776–81.