Alpha-Lipoic Acid

Common Names

  • Thioctic acid
  • Lipoate
  • Lipoic acid
  • ALA
  • Thioctan

For Patients & Caregivers

How It Works

Alpha-lipoic acid is an antioxidant. There is no evidence to support its use to treat diseases such as diabetes, HIV, liver disease, or cancer.

Alpha lipoic acid is a compound naturally produced by the body that acts as a cofactor in the production of energy. Laboratory studies show that alpha lipoic acid and its metabolite, dihydrolipoic acid (DHLA), have metal-chelating and free radical-scavenging capacities. In addition, DHLA is able to repair oxidative damage and regenerate antioxidants such as vitamin C, vitamin E, and glutathione. However, when taken orally, the amount of alpha lipoic acid delivered to the body varies. Applying a cream containing Alpha-lipoic acid may help prevent wrinkling of skin due to sun exposure.

Purported Uses

  • As an antioxidant
    Laboratory studies support this use.
  • To prevent and treat cancer
    Alpha-lipoic acid is an antioxidant. However, there is no evidence that it can be used to treat cancer.
  • To relieve conditions related to diabetes, such as diabetic neuropathy
    Data from some studies suggest efficacy.
  • To treat drug-related toxicity of the auditory nerve
    No clinical trials have been performed to evaluate this use.
  • To treat HIV and AIDS
    No scientific evidence supports this use.
  • To treat liver disease
    A few studies show that alpha-lipoic acid may prevent nonalcoholic liver disease. More research is needed.

Side Effects

  • Alpha-lipoic acid can lower blood sugar level.

Special Point

Taking alpha lipoic acid appears to be relatively safe, but it has yet to be proven beneficial for any of its proposed uses. Diabetic patients should consult their physicians before using alpha lipoic acid.

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For Healthcare Professionals

Scientific Name

1,2-dithiolane-3-pentanoic acid

Clinical Summary

Endogenous cofactor found in all eukaryotic and prokaryotic cells that can be obtained in the diet. Patients take this supplement to treat and prevent cancer and to treat diabetes, diabetic neuropathies, HIV/AIDS, and liver disease. Alpha-lipoic acid plays a crucial role in energy production, acts as a potent antioxidant, and exerts apoptotic effects on tumor cells (1) (2) (3).

In human studies, alpha-lipoic acid improved insulin sensitivity, vasodilation, and polyneuropathy in patients with diabetes mellitus (5) (6). Analyses of clinical trials using alpha-lipoic acid showed significant reductions in neuropathic symptoms in diabetic patients (7) (21). Studies have also been conducted to determine its role in reversing neuropathies (8) (9) and liver disease (10) (11), producing mixed results. Findings from another study suggest that topical application of creams containing alpha-lipoic acid may help prevent photoaging of facial skin (12). Furthermore, current data suggest protective effects of antioxidants against Alzheimer’s disease, but a new study failed to find similar effects with a combination of Coenzyme Q, vitamins C, E, and lipoic acid (20).

High doses of alpha-lipoic acid can cause hypoglycemic symptoms (4). In addition, because of its antioxidant effects, alpha-lipoic acid may antagonize the effects of chemotherapy and radiation therapy.

Food Sources

Organ meats, spinach, broccoli, tomato, peas, Brussels sprouts, rice bran

Purported Uses

  • Cancer prevention
  • Cancer treatment
  • Diabetes
  • Diabetic neuropathy
  • AIDS
  • Liver disease

Mechanism of Action

Alpha-lipoic acid acts as a lipophilic free radical scavenger. Dihydrolipoic acid (DHLA), a reduced form of lipoic acid, has more potent antioxidant effects. It can assist in repairing oxidative damage and regenerate endogenous antioxidants such as vitamin C, vitamin E, and glutathione. Both DHLA and lipoic acid also have metal chelating capacities. As a lipoamide, alpha-lipoic acid functions as a cofactor in various multienzyme systems involved in the decarboxylation of alpha-keto acids such as pyruvate (13) (14) (15).

Alpha-lipoic acid was shown to bring about cell cycle arrest in G0/G1 phases in FaDu and Jurkat human tumor cell lines (1). It was also found to scavenge reactive oxygen species in MCF-7 breast cancer cells (16). Reduction of reactive oxygen species was then followed by cancer cell growth arrest and apoptosis (16). In another study, lipoic acid was shown to induce cell death in colorectal cancer cells independent of their p53 status, and to enhance the cytotoxicity of 5-fluorouracil (22).

Adverse Reactions

Reported: Hypoglycemia
 (4) (13)

Herb-Drug Interactions

May have synergetic effects with hypoglycemic agents (7).

Dosage (OneMSK Only)


  1. van de MK, Chen JS, Steliou K, Perrine SP, Faller DV. Alpha-lipoic acid induces p27Kip-dependent cell cycle arrest in non-transformed cell lines and apoptosis in tumor cell lines. J Cell Physiol 2003;194:325-40.

  2. Simbula G, Columbano A, Ledda-Columbano GM, et al. Increased ROS generation and p53 activation in alpha-lipoic acid-induced apoptosis of hepatoma cells. Apoptosis 2007 Jan;12(1):113-23.

  3. Shi DY, Liu HL, Stern JS, et al. Alpha-lipoic acid induces apoptosis in hepatoma cells via the PTEN/Akt pathway. FEBS Lett. 2008 May 28;582(12):1667-71.

  4. Gu XM, Zhang SS, Wu JC, et al. Efficacy and safety of high-dose á-lipoic acid in the treatment of diabetic polyneuropathy. Zhonghua Yi Xue Za Zhi. 2010 Sep;90(35):2473-2476.

  5. Heinisch BB, Francesconi M, Mittermayer F, et al. Alpha-lipoic acid improves vascular endothelial function in patients with type 2 diabetes: a placebo-controlled randomized trial. Eur J Clin Invest. 2010 Feb;40(2):148-54.

  6. Ziegler D, Nowak H, Kempler P, Vargha P, Low PA. Treatment of symptomatic diabetic polyneuropathy with the antioxidant alpha-lipoic acid: a meta-analysis. Diabet.Med 2004;21:114-21.

  7. Biewenga GP, Haenen GR, Bast A. The pharmacology of the antioxidant lipoic acid. Gen Pharmacol 1997;29:315-31.

  8. Schupke H, et al. New metabolic pathways of a-lipoic acid. Drug Metab Disp 2001;29:855-62.

  9. Sen CK, Packer L. Thiol homeostasis and supplements in physical exercise. Am J Clin Nutr 2000;72(suppl):653S-69S.

  10. Teichert J, et al. Investigations on the pharmacokinetics of alpha-lipoic acid in healthy volunteers. Int J Clin Pharmacol Ther 1998;36:625-8.

  11. Galasko DR, Peskind E, Clark CM, et al; for the Alzheimer’s Disease Cooperative Study. Antioxidants for Alzheimer Disease: A Randomized Clinical Trial With Cerebrospinal Fluid Biomarker Measures. Arch Neurol. 2012 Jul;69(7):836-41.

  12. Papanas N, Ziegler D. Efficacy of α-lipoic acid in diabetic neuropathy. Expert Opin Pharmacother. 2014 Dec;15(18):2721-31.

  13. Dörsam B, Göder A, Seiwert N, Kaina B, Fahrer J. Lipoic acid induces p53-independent cell death in colorectal cancer cells and potentiates the cytotoxicity of 5-fluorouracil. Arch Toxicol. 2015 Oct;89(10):1829-46.

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