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Alpha lipoic acid supplement: benefits, risks and how to choose

By the Life in Good Form editors. Updated 2026-10-15.

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What alpha lipoic acid is

MSK's About Herbs database describes ALA as a cofactor naturally found in cells and obtained from foods. It is sometimes called a universal antioxidant because it is both water- and fat-soluble. Its reduced form, dihydrolipoic acid, helps regenerate other antioxidants such as vitamin C, vitamin E and glutathione.

Food sources include organ meats, spinach, broccoli, tomato, peas, Brussels sprouts and rice bran. Supplements are marketed as antioxidants and are also used alongside treatment for neuropathy and blood sugar control.

What the research shows

Diabetes and nerves. Studies of oral and intravenous ALA suggest better insulin sensitivity, blood vessel function and neuropathy symptoms in people with diabetes, although earlier studies on reversing neuropathy and liver disease had mixed results.

Other uses. Preliminary data suggest long-term use may help preserve walking ability in secondary progressive multiple sclerosis. ALA produced mild weight and waist reductions in overweight people, and long-term R-ALA gave modest weight loss. A combination of coenzyme Q, vitamin C, vitamin E and ALA showed no protective effect for Alzheimer's disease, and ALA did not help fibromyalgia in one trial.

In medical settings. MSK reports that ALA helped wound healing and scarring after cesarean section, reduced pain after carpal tunnel surgery, and lowered inflammation markers but not recurrence in people with atrial fibrillation after ablation. In cancer care it may be a useful add-on for paclitaxel-related neuropathy and for protecting the heart during doxorubicin, and it reduced radiation mouth sores. Because it may also blunt chemotherapy and radiation, these uses belong with your care team, not self-treatment.

Safety: blood sugar and children

• Low blood sugar. MSK lists hypoglycemia as a side effect, and ALA may add to the effects of diabetes medicines. NOW Foods advises consulting a physician if you take insulin or anti-diabetes drugs or have diabetes.
• Insulin autoimmune syndrome. Rare cases of spontaneous low blood sugar linked to ALA have been reported, about 27 cases overall, mostly in Japan. Some needed steroid treatment.
• Digestive effects. Nausea, vomiting and indigestion are reported.
• High doses. Severe intoxication has followed high-dose use, including a death.
• Children. Accidental swallowing by toddlers has caused convulsions, and a teenager had seizures and bleeding problems after about 30 mg/kg. Store it out of reach.
• Cancer treatment. MSK notes ALA may interfere with chemotherapy and radiation because of its antioxidant effects. Ask your oncology team first.
• Kidneys. One case of membranous nephropathy resolved after stopping ALA.

Doses and forms

• Strengths. NOW Foods sells 100 mg regular strength and 600 mg Extra Strength capsules. The 600 mg product is taken once daily, preferably with a meal.
• Added ingredients. NOW Foods' 600 mg capsule also contains 30 mg grape seed extract and 5 mg black pepper fruit extract (Bioperine).
• R-ALA. R-lipoic acid is a form with increased bioavailability, according to MSK.
• Nerve blends. Some products pair ALA with benfotiamine and vitamin B12. Check each amount.

How to choose an ALA supplement

• Talk with your doctor first if you have diabetes. ALA can lower blood sugar further.
• Pick a strength with your doctor. Capsules range widely, from NOW Foods' 100 mg to 600 mg.
• Check extras. Black pepper extract and other additives can matter if you take medicines.
• Child-resistant storage. Keep the bottle locked away given the poisoning reports.
• See a doctor for nerve symptoms. Numbness or burning in the feet needs a medical evaluation.

What to look for when you buy

Questions people ask

What is alpha lipoic acid good for?

Studies suggest it may help insulin sensitivity and diabetic neuropathy symptoms, though results have been mixed. It is also sold as an antioxidant.

Can alpha lipoic acid lower blood sugar too much?

Yes. Hypoglycemia is a known side effect, and ALA may add to diabetes medicines. Talk with your doctor and monitor your levels.

When should I take alpha lipoic acid?

Follow the label. NOW Foods directs taking its 600 mg capsule once daily, preferably with a meal.

Is alpha lipoic acid safe for children?

No. Accidental ingestion by children has caused seizures and poisoning. Keep it out of reach.

Can I take ALA during chemotherapy?

Ask your oncology team first. MSK notes it may interfere with chemotherapy and radiation.

Sources

• Alpha-Lipoic Acid (mskcc.org), Memorial Sloan Kettering Cancer Center, About Herbs
• Alpha Lipoic Acid, Extra Strength 600 mg Veg Capsules (www.nowfoods.com/products/supplements/alpha-lipoic-acid-extra-strength-600-mg-veg-capsules), NOW Foods

Sources checked 2026-10-15.