Is Alpha Lipoic Acid Safe to Use?
As a general antioxidant to support metabolic activity, especially against aging, experts recommend taking 50 mg twice a day. Clinical trials show using very high doses of alpha lipoic acid supplements (1800-2400 mg/day) for months caused no adverse side effects. Alpha lipoic acid has also been administered intravenously at 600-1200 mg/day without toxic side effects. Moderate (450 mg/day orally) to high doses of alpha lipoic acid have been used safely even in patients with suppressed immune systems. Although rare, there have been reports that higher doses could cause skin rash, nausea or stomach upset, along with nervousness, fatigue and insomnia. (i.2, 9-10, 28)
May Trigger Dangerous Rare Genetic Disease
Alpha lipoic acid has also been associated with cases of Insulin Autoimmune Syndrome (IAS). Also known as Hirata disease, IAS is a rare genetic disease that has occurred more often in Japanese people. Patients with IAS develop antibodies to insulin, causing episodes of hypoglycemia attacks. The condition is reversible and not associated with diabetes. Historically, half of IAS cases have occurred after taking medicines that contain sulfur-hydrogen (sulfhydryl) molecules. This has led to speculation that sulfhydryl-containing drugs may trigger IAS in genetically susceptible people. (i.29-30)
Alpha lipoic acid also contains sulfhydryl molecules, and some researchers speculated that the amounts of alpha lipoic acid found in supplements (much higher than that found in food) could also trigger IAS. A more recent publication in 2014 reported multiple cases that confirm that suspicion, linking alpha lipoic acid supplements (600 mg) with spontaneous, severe episodes of low blood sugar — sometimes up to 3 months after taking alpha lipoic acid. (i.29-30)
All cases were linked to one of two specific genetic variations, or alleles. One of these alleles had already been identified in Japanese patients with IAS. However, the recent cases identified a different, but close related allele found in Caucasian and other populations. This new allele is much more common, and raises the concern that the widespread use of alpha lipoic acid could trigger IAS in a greater number of people. The bottom line is that you should discuss taking alpha lipoic acid with your healthcare provider, especially if you are experiencing any symptoms of low blood sugar. (i.30)
Fatal Alpha Lipoic Acid Overdose
In January, 2014 a report surfaced about a fatal overdose of alpha lipoic acid. According to doctors in Duesseldorf, Germany, a young teenage girl intending suicide ingested a massive dose (at least 6000 mg) of alpha lipoic acid supplements. Despite emergency treatment she died of multiple-organ failure within 24 hours of ingestion. The reporting doctors concluded her death was attributable to alpha lipoic acid overdose. (i.30)
Thiamine Deficiency
Based on animal studies involving severely thiamine-deficient rats, some experts advise that you shouldn't take alpha lipoic acid if you're deficient in thiamine (vitamin B1). Others indicate that the alpha lipoic acid dosage involved in this study was very high. They suggest that patients susceptible to thiamine deficiency and taking high doses of alpha lipoic acid may need to take a thiamine supplement to counteract this potential effect. Who might be susceptible? One example would be those who suffer from alcoholism. It causes Wernicke-Korsakoff syndrome, a condition characterized by thiamine deficiency that can lead to dementia. (i.1, 18)
Interestingly, research suggests that supplementing with alpha lipoic acid and thiamine may help patients with maple syrup urine disease. This condition is a genetic metabolic disorder linked to thiamine deficiency. Alpha lipoic acid and thiamine are also helpful in treating Leigh's disease, another genetic condition, which is similar to Wernicke-Korsakoff syndrome. (i.8, 18, 29)
Possible Drug Interactions
If you're currently being treated with any of the following medications, you shouldn't use alpha lipoic acid without discussing it with your health-care provider: (i.1, 18)
Insulin and drugs that lower blood sugar. Alpha lipoic acid can combine with these drugs to further reduce blood sugar levels, resulting in hypoglycemia (low blood sugar). Tell your doctor before taking alpha lipoic acid, and monitor your blood sugar levels closely; your doctor may need to adjust your medication doses.
Thyroid-regulating medications (e.g., Levothyroxine). Alpha-lipoic acid may lower levels of thyroid hormone. Blood hormone levels and thyroid function tests should be monitored.