Alpha-lipoic acid is an antioxidant that is manufactured in the human body. Antioxidants are substances that work by attacking "free radicals," waste products created when the body turns food into energy. There are also many sources of free radicals in the environment such as ultraviolet rays, radiation, and toxic chemicals in cigarette smoke, car exhaust, and pesticides. Free radicals cause harmful chemical reactions that can damage cells in the body, making it harder for the body to fight off infections. As a result a person becomes more susceptible to long term diseases such as diabetes and liver damage.

General

Alpha-lipoic acid works together with other antioxidants such as vitamins C and E. It is important for growth, helps to prevent cell damage, and helps the body rid itself of harmful substances.

Diabetes

Several studies suggest that treatment with ALA may help reduce pain, burning, itching, tingling, and numbness in people who have nerve damage (called peripheral neuropathy) caused by diabetes. Alpha-lipoic acid has been used for years for this purpose in Europe. Other studies have shown that alpha-lipoic acid speeds the removal of glucose (sugar) from the blood of people with diabetes and that this antioxidant may prevent kidney damage associated with diabetes in animals.

Liver Disease

Alpha-lipoic acid may prove useful in the treatment of chronic hepatitis because it relieves stress on the liver and helps rid the body of toxins. There have been several case reports of use of alpha-lipoic acid in combination with silymarin (milk thistle) and selenium (a substance with liver-protecting and antioxidant properties) to help treat hepatitis C (a serious type of hepatitis contracted from blood and bodily fluids that does not have an adequate cure or treatment).

It has also been used in conjunction with silymarin to treat Amanita poisoning. Amanita is a highly poisonous mushroom that causes liver damage.

Brain Function and Stroke

Because alpha-lipoic acid can pass easily into the brain, it has protective effects on brain and nerve tissue and shows promise as a treatment for stroke and other brain disorders involving free radical damage. Animals treated with alpha-lipoic acid, for example, suffered less brain damage and had a four times greater survival rate after a stroke than the animals who did not receive this supplement. While animal studies are encouraging, more research is needed to understand whether this benefit applies to people as well.

Other

Additional conditions for which alpha-lipoic acid may prove useful include heart failure, human immunodeficiency virus (HIV), cataracts, and glaucoma. More research is underway in these areas.

Good food sources of alpha-lipoic acid include spinach, broccoli, beef, yeast (particularly Brewer's yeast), and certain organ meats (such as the kidney and heart).

Alpha-lipoic acid supplements are available in capsule form.

Pediatric

There are no known scientific reports on the pediatric use of alpha-lipoic acid. Therefore, it is not currently recommended for children.

Adult

Alpha-lipoic acid can be purchased in dosages ranging 30 mg to 100 mg tablets. Currently there are no established recommended doses for supplementation. For general antioxidant support, the recommended dose of ALA is 20 mg to 50 mg per day.

Manufacturers of alpha-lipoic acid suggest one or two 50-mg capsules daily as a dietary supplement.

Studies that have been successful in improving nerve function in diabetics have used 600 mg of alpha-lipoic acid per day in divided doses.

Because of the potential for side effects and interactions with medications, dietary supplements should be taken only under the supervision of a knowledgeable healthcare provider. This is especially true for those who are pregnant or breastfeeding.

Skin rash has been reported rarely from alpha-lipoic acid.

Finally, because alpha-lipoic acid has been associated with improved blood sugar control, people with diabetes should follow their blood sugar levels carefully when taking this supplement in order to avoid hypoglycemia (low blood sugar). Your doctor may decide that a reduction in dosage of insulin or oral blood sugar-lowering drugs is needed if you are taking this supplement.

If you are currently being treated with any of the following medications, you should not use alpha-lipoic acid without first talking to your healthcare provider.

Amikacin and Gentamicin

In an animal study, alpha-lipoic acid supplements reduced side effects, particularly toxicity to the ear, associated with these antibiotics. Additional studies are needed to confirm these effects in people.

Cisplatin and Cyclophosphamide

The use of alpha-lipoic acid supplements in animals protected against toxic side effects associated with these medications.

Thyroid-regulating Medications, Levothyroxine

Rats given alpha-lipoic acid supplements had altered thyroid hormone function, but improved cholesterol levels. Blood hormone levels and thyroid function tests should be monitored closely in people taking thyroid hormones who are also taking alpha-lipoic acid.

Androne L, Gavan NA, Veresiu IA, Orasan R. In vivo effect of lipoic acid on lipid peroxidation in patients with diabetic neuropathy. In Vivo. 2000;14(2):327-330

Berkson BM. A conservative triple antioxidant approach to the treatment of hepatitis C. Combination of alpha lipoic acid (thioctic acid), silymarin, and selenium: three case histories. Med Klin. 1999;94 Suppl 3:84-89.

Clark WM, Rinker LG, Lessov NS, Lowery SL, Cipolla MJ. Efficacy of antioxidant therapies in transient focal ischemia in mice. Stroke. 2001;32(4):1000-1004.

Conlon BJ, Aran JM, Erre JP, et al. Attenuation of aminoglycoside-induced cochlear damage with the metabolic antioxidant alpha-lipoic acid. Hear Res. 1999;128:40-44.

Faust A, Burkart V, Ulrich H, et al. Effect of lipoic acid on cyclophosphamide-induced diabetes and insulitis in non-obese diabetic mice. Int J Immunopharmacol. 1994;16:61-66.
Head KA. Natural therapies for ocular disorders, part two: cataracts and glaucoma. Altern Med Rev. 2001;6(2):141-166.

Hruby K, Csomos G, Fuhrmann M, Thaler H. Chemotherapy of Amanita phalloides poisoning with intravenous silibinin. Hum Exp Toxicol. 1983;2(2):183-195.

Lynch MA. Lipoic acid confers protection against oxidative injury in non-neuronal and neuronal tissue. Nutr Neurosci. 2001;4(6):419-438.

Melhem MF, Craven PA, Derubertis FR. Effects of dietary supplementation of alpha-lipoic acid on early glomerular injury in diabetes mellitus. J Am Soc Nephrol. 2001;12:124-133.

Monograph:Alpha-Lipoic Acid. Altern Med Rev. 1998;3(4):308-311.

Nagamatsu M, Nickander KK, Schmelzer JD,et al. Lipoic acid improves nerve blood flow, reduces oxidative stress, and improves distal nerve conduction in experimental diabetic neuropathy. Diabetes Care. 1995;18:1160-1167.

Packer L, Kraemer K, Rimbach G. Molecular aspects of lipoic acid in the prevention of diabetes complications. Nutrition. 2001;17(10):888-895.

Packer L, Tritschler HJ, Wessel K. Neuroprotection by the metabolic antioxidant alpha-linoic acis. Free Radic Biol Med. 1997;22:359–378.

Packer L, Witt EH, Tritschler HJ. Alpha-lipoic acid as a biological antioxidant. Free Rad Bio Med. 1995;19(2):227-250.

Panigrahi M, Sadguna Y, Shivakumar BR, Kolluri SV, Roy S, Packer L, Ravindranath V. Alpha-Lipoic acid protects against reperfusion injury following cerebral ischemia in rats. Brain Res. 1996;717(1-2):184-188.

Parish RC, Doering PL. Treatment of Amanita mushroom poisoning: a review. Vet Hum Toxicol. 1986;28(4):318-22.

Rybak LP, Husain K, Whitworth C, et al. Dose dependent protection by lipoic acid against cisplatin-induced ototoxicity in rats: antioxidant defense system. Toxicol Sci. 1999;47:195-202.

Sandhya P, Varalakshmi P. Effect of lipoic acid administration on gentamicin-induced lipid peroxidation in rats. J Appl Toxicol. 1997;17:405-408.

Segermann J, Hotze A, Ulrich H, et al. Effect of alpha-lipoic acid on the peripheral conversion of thyroxine to triiodothyronine and on serum lipid-, protein- and glucose levels. Arzneimittelforschung. 1991;41:1294-1298.

Ziegler D, Gries FA. Alpha-lipoic acid in the treatment of diabetic peripheral and cardiac autonomic neuropathy. Diabetes. 1997;46 (suppl 2):S62–66.

Ziegler D, Reljanovic M, Mehnert H, Gries FA. Alpha-lipoic acid in the treatment of diabetic polyneuropathy in Germany: current evidence from clinical trials. Exp Clin Endocrinol Diabetes. 1999; 107:421-430.