Alpha Lipoic Acid

  • Vitamins & Supplements
  • Updated July 10, 2016

Alpha-lipoic acid (ALA) is a synthetic version of lipoic acid, which helps cells make energy. It has antioxidant properties and may reduce inflammation. While ALA supplements are generally considered safe, clinical research is very limited particularly for cognition, and it has shown variable effects on patients with mild to moderate Alzheimer's disease.


No randomized controlled trials have examined whether ALA can prevent or treat dementia, though two clinical trials reported that ALA, in conjunction with other supplements, did not benefit patients with Alzheimer’s disease. Our search identified:

• 0 meta-analyses or systematic reviews
• 2 randomized controlled trials and 2 open-label (not placebo-controlled) studies in Alzheimer's patients
• 0 observational studies
• Multiple preclinical studies

Potential Benefit

Preclinical research suggests that ALA scavenges free radicals, reduces inflammation, and may protect brain cells from conditions such as stroke, multiple sclerosis, and Alzheimer's disease. Preclinical studies also indicate that ALA or a combination of ALA and regular exercise may improve certain aspects of learning and memory [3][4]. However, no clinical studies suggest that ALA can prevent dementia or improve cognition.

For Dementia Patients

In clinical trials, ALA treatment for mild cognitive impairment and Alzheimer's patients has shown mixed results. In one clinical trial, Alzheimer's patients' cognitive function worsened after 16 weeks of treatment with an antioxidant cocktail of ALA (900 mg), vitamin E, and vitamin C. Though the supplements reduced evidence of oxidative stress in the brain by 19 percent, they did not appear to help patients' cognition [5]. In another clinical trial, Alzheimer's patients who took a combination of 600 mg of ALA with omega-3 fatty acids for one year showed less cognitive and functional decline [6]. Two open-label pilot studies suggested that ALA, in addition to standard care, might benefit Alzheimer’s patients with diabetes or dementia patients [7][8].


Evidence from clinical trials suggests that ALA is generally safe for healthy individuals, although one clinical trial reported occasional minor stomach discomfort at high doses. Additional side effects may include nausea and skin rash. Allergic reactions can occur as can a potential lowering of blood sugar [9].

NOTE: This is not a comprehensive safety evaluation or complete list of potentially harmful drug interactions. It is important to discuss safety issues with your physician before taking any new supplement or medication.

How to Use

Alpha-lipoic acid is found in low amounts in foods such as spinach, broccoli, potatoes, carrots, beets, and red meat. ALA is also widely available as an over-the-counter supplement. There are no official recommended doses for ALA supplements, but clinical trials with Alzheimer's patients have used doses ranging from 600 to 900 mg/day for up to 2 years without reporting serious side effects.

Learn More

Information including possible side effects at Drugs.com

"Dietary Supplements: What You Need to Know," from the U.S. Food and Drug Administration (FDA)

Check for drug-drug and drug-supplement interactions on Drugs.com


  1. Packer L, Tritschler HJ, Wessel K (1997) Neuroprotection by the metabolic antioxidant alpha-lipoid acid. Free radical biology & medicine 22, 359-378.
  2. Smith AR, Shenvi SV, Widlansky M et al. (2004) Lipoic acid as a potential therapy for chronic diseases associated with oxidative stress. Current medicinal chemistry 11, 1135-1146.
  3. Cho JY, Um HS, Kang EB et al. (2010) The combination of exercise training and alpha-lipoic acid treatment has therapeutic effects on the pathogenic phenotypes of Alzheimer's disease in NSE/APPsw-transgenic mice. International journal of molecular medicine 25, 337-346.
  4. Farr SA, Price TO, Banks WA et al. (2012) Effect of alpha-lipoic acid on memory, oxidation, and lifespan in SAMP8 mice. Journal of Alzheimer's disease : JAD 32, 447-455.
  5. Galasko DR, Peskind E, Clark CM et al. (2012) Antioxidants for Alzheimer disease: a randomized clinical trial with cerebrospinal fluid biomarker measures. Archives of neurology 69, 836-841.
  6. Shinto L, Quinn J, Montine T et al. (2014) A randomized placebo-controlled pilot trial of omega-3 fatty acids and alpha lipoic acid in Alzheimer's disease. Journal of Alzheimer's disease : JAD 38, 111-120.
  7. Fava A, Pirritano D, Plastino M et al. (2013) The Effect of Lipoic Acid Therapy on Cognitive Functioning in Patients with Alzheimer's Disease. J Neurodegener Dis 2013, 454253.
  8. Hager K, Kenklies M, McAfoose J et al. (2007) Alpha-lipoic acid as a new treatment option for Alzheimer's disease--a 48 months follow-up analysis. Journal of neural transmission Supplementum, 189-193.
  9. Drugs.com ALA Side Effects.