Alpha-lipoic acid is an antioxidant that’s in many foods, and it’s made naturally in our bodies. For many years, high doses of alpha-lipoic acid supplements have been used in parts of Europe for certain types of nerve damage. Studies suggest that they might also help with type 2 diabetes.

Why do people take alpha-lipoic acid?

We have strong evidence that alpha-lipoic acid supplements help with type 2 diabetes. Several studies have found that they can improve insulin resistance. Studies also found that alpha-lipoic acid supplements can help with neuropathy — nerve damage — caused by diabetes or cancer treatment. They seem to reduce symptoms like pain, tingling, and prickling in the feet and legs. It may also help protect the retina from some of the damage that can occur in people with diabetes.

Although these uses are promising, diabetes and cancer obviously need proper medical treatment. So don’t treat yourself on your own with supplements. Instead, see your doctor and ask if alpha-lipoic acid might help.

There’s some early evidence that long-term use of alpha-lipoic acid might help with the symptoms of dementia. Other studies suggest that an alpha-lipoic acid cream might help skin damage related to aging. However, more research needs to be done.

Alpha-lipoic acid has also been researched as a treatment for many other conditions. These include Amanita mushroom poisoning, glaucoma, kidney disease, migraines, and peripheral arterial disease. So far, the evidence is not clear.

How much alpha-lipoic acid should you take?

Because alpha-lipoic acid is an unproven treatment, there is no established dose. However, studies have used between 600-1,200 milligrams daily for diabetes and neuropathy; one review concluded that the evidence is convincing for the use of 600 milligrams daily for three weeks on symptoms of diabetic neuropathy. Some studies have used intravenous alpha-lipoic acid instead of oral supplements.

Can you get alpha-lipoic acid naturally from foods?

Many foods contain alpha-lipoic acid in very low amounts. They include spinach, broccoli, yams, potatoes, yeast, tomatoes, Brussels sprouts, carrots, beets, and rice bran. Red meat — and particularly organ meat — is also a source of alpha-lipoic acid.

What are the risks of taking alpha-lipoic acid?

Side effects. Generally, side effects are uncommon. These supplements could cause nausea, dizziness, or a rash. Topical alpha-lipoic acid can irritate the skin.

Risks. Because alpha-lipoic acid can lower blood sugar, check with a doctor before using it if you have diabetes. Your doctor might want to test your glucose levels regularly while you use alpha-lipoic acid supplements. If you have thyroid problems, a thiamine deficiency, or any other medical issue, talk to your doctor before you start taking alpha-lipoic acid supplements.

Interactions. If you take any medicines or supplements regularly, see your doctor before you start using alpha-lipoic acid. People with diabetes need to be especially careful. Using it along with diabetes drugs could make blood sugar levels drop too low. Alpha-lipoic acid might decrease the effect of chemotherapy drugs. It could also interact with antibiotics, anti-inflammatories, tranquilizers, vasodilators, and drugs for osteoarthritis.

Given the lack of evidence about its safety, alpha-lipoic acid is not recommended for children or for women who are pregnant or breastfeeding.