Alpha Lipoic Acid

non-nutrient/non-botanicallipoic acid

Take with food

What is it

Alpha-lipoic acid (ALA) is a sulfur-containing compound made naturally in the body and found in small amounts in foods. It functions as a cofactor in mitochondrial energy production and as an antioxidant that works in both water- and fat-soluble environments.

How it works

Alpha-lipoic acid is a cofactor for pyruvate dehydrogenase and other mitochondrial enzymes critical for converting glucose to energy. Its unique structure — bearing both polar and non-polar groups — lets it cross cell membranes easily and act as an antioxidant in both aqueous and lipid environments. ALA also regenerates other antioxidants including vitamins C and E, glutathione, and coenzyme Q10. It may improve insulin sensitivity and has been studied for diabetic neuropathy, where it appears to reduce nerve pain in some trials. Both R-ALA (the natural form) and S-ALA (the synthetic mirror image) are present in racemic supplements, though R-ALA appears more biologically active.

Evidence for 5 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Diabetic peripheral neuropathy

Grade B

Good evidence

Oral and IV ALA at 600 mg or more per day reduces neuropathic pain in some trials, including the SYDNEY and ALADIN studies. Most evidence is from Germany where ALA is an approved treatment.

Insulin sensitivity in type 2 diabetes

Grade C

Moderate evidence

Some trials show modest improvements in insulin sensitivity and fasting glucose. Not a standard treatment.

Weight loss adjunct

Grade C

Moderate evidence

Some trials show small reductions in body weight (around 1 kg) at 1,200 to 1,800 mg/day. Effect is modest.

Skin aging (topical)

Grade C

Moderate evidence

Topical ALA may improve photoaging in some trials; oral effect on skin is less established.

Cognitive function

Grade D

Mixed evidence

Limited evidence in humans for cognitive enhancement, despite mechanistic plausibility.

3 commercial forms

Racemic alpha-lipoic acid (R+S)

common, inexpensive 50/50 mixture

The standard supplement form, a mixture of R- and S-ALA. Most clinical studies have used this form.

R-alpha-lipoic acid (R-ALA)

natural isomer, more biologically active

The naturally occurring form. May be more bioavailable per mg than racemic. More expensive.

Sustained-release ALA

smoother blood levels

Designed to release more slowly to maintain blood levels. Limited data on whether this improves clinical outcomes.

Dosage

Common oral doses are 300 to 600 mg per day for general antioxidant use, and 600 to 1,800 mg per day in trials for diabetic neuropathy. Higher doses are sometimes used short-term under medical supervision. No formal upper limit is established; rare cases of low blood sugar have occurred at very high doses.

When and how to take it

Alpha-lipoic acid absorbs better on an empty stomach (30 minutes before a meal). Splitting doses (e.g., 300 mg twice daily) maintains more consistent blood levels than a single dose. If taking with diabetes medications, monitor blood sugar carefully.

Food sources

Food	Amount	%DV
Spinach (cooked), 1/2 cup	trace amounts	—
Broccoli, 1/2 cup	trace amounts	—
Beef (organ meats)	trace amounts	—
Brewer's yeast	trace amounts	—

Safety

Generally well tolerated. Side effects include nausea, skin rash, and rarely low blood sugar (especially with diabetes medications). Some case reports describe insulin autoimmune syndrome (a rare cause of severe hypoglycemia) in genetically susceptible people, primarily of Japanese descent. People with thiamine deficiency (such as heavy alcohol users) should ensure adequate thiamine when supplementing ALA.

Who should be cautious

People with diabetes should monitor blood sugar carefully. People on thyroid medication should monitor levels. People with thiamine deficiency or alcohol use disorder should ensure thiamine repletion first. Pregnant women should avoid due to limited safety data. People of Japanese ethnicity may be at slightly higher risk of insulin autoimmune syndrome.

Interactions

Can lower blood sugar — combined with insulin or oral diabetes medications, monitor glucose. May reduce thyroid hormone levels in some people on levothyroxine. May enhance chemotherapy or radiation effects (consult oncologist). May reduce levodopa effectiveness in Parkinson's.

Frequently asked questions

Does alpha-lipoic acid help diabetic neuropathy?⌄

Yes, evidence supports modest benefit at 600 mg or more per day. It is an approved neuropathy treatment in Germany.

Is R-ALA better than racemic?⌄

Possibly, since R-ALA is the natural form and may be more bioavailable. Most trials used racemic ALA, so the evidence base is larger for that form.

Can ALA lower blood sugar?⌄

Yes, modestly. People on diabetes medications should monitor glucose to avoid hypoglycemia.

How should I take alpha-lipoic acid?⌄

Take on an empty stomach for best absorption. Split larger doses across the day.

Is ALA safe long-term?⌄

Generally yes at typical doses. Watch for hypoglycemia if diabetic; rare cases of insulin autoimmune syndrome have been reported.

Track Alpha Lipoic Acid with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.