Alpha-lipoic acid

Alpha-Lipoic Acid (ALA)
Also known as: ALA, R-lipoic acid, Thioctic acid
Supplement

Content by: OpenSupplement Editorial Team  |  Medical review: pending  |  Last updated: April 13, 2026

Supplement Score
Alpha-lipoic acid300-600 mg/day | $15-25/mo
Safety4
Interactions3
Cost4
Evid.Onset
Metabolic syndrome
3.53
Cognitive decline
22
3 PubMed references cited
4–5 Strong2–3 Emerging1 Weak|Methodology

TL;DR

  • The 'Universal Antioxidant' that works in both water and fat

  • High evidence for reducing diabetic neuropathy (nerve pain)

  • Moderate evidence for blood sugar and weight loss support

  • Low evidence for preventing age-related cognitive decline

  • Generally safe; may cause a harmless 'sulfur' smell in urine

  • Cost: ~$15-25/month

  • Best for: Diabetic nerve pain, metabolic syndrome support

What it is

Alpha-Lipoic Acid (ALA) is a fatty acid found inside every cell in the body. It's unique because it is both water-soluble and fat-soluble, allowing it to provide antioxidant protection everywhere from the blood to the brain. It also helps 'recycle' other antioxidants like Vitamin C and Glutathione.

ALA plays a key role in energy metabolism within the mitochondria. As we age, our natural production of ALA declines, and our cells become more vulnerable to oxidative stress and 'glycation' (damage caused by sugar).

What the research says

Relevance: High
Typical dose: 300-600 mg/day

ALA is a multi-talented metabolic tool. Neuropathy. This is its strongest application. Multiple meta-analyses (such as the ALADIN trials) show that ALA significantly reduces the burning, tingling, and numbness associated with diabetic peripheral neuropathy. Insulin Sensitivity. A study in Metabolism showed that ALA improved insulin sensitivity by 18-25% in Type 2 diabetics. Weight Loss. A 2017 meta-analysis found that ALA supplementation resulted in a modest but significant reduction in body weight and BMI compared to placebo. [1][2]

Relevance: Low
Typical dose: 300-600 mg/day

The evidence for brain health is mostly theoretical. Mechanism. Because ALA crosses the blood-brain barrier and reduces oxidative stress in the mitochondria, it is a prime candidate for neuroprotection. Evidence. Small trials in Alzheimer's patients have shown a potential slowing of cognitive decline, but large, high-quality RCTs are missing. It remains a 'promising' rather than 'proven' cognitive supplement. [3]

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Alpha-lipoic acid on Amazon

$15-25/mo (estimated)
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Safety

Generally safe. Common side effects include a skin rash or mild GI upset. It is a sulfur-containing compound, so it may cause urine to smell like asparagus. People with Thiamine (B1) deficiency should be cautious, as ALA can lower B1 levels.

Interactions

  • Diabetes Meds: Strong additive effect; monitor for hypoglycemia.
  • Chemotherapy: May interfere with the action of certain chemo drugs due to its antioxidant power.
  • Thyroid Meds: May lower T3 levels; monitor thyroid function.

Dosing

For Neuropathy: 600 mg daily on an empty stomach. For Metabolic Support: 300-600 mg daily. Form: R-Lipoic Acid (the natural form) is better absorbed than the cheaper S-form, though most studies use a mix.

Cost

Moderate. $15-25 per month.

The bottom line

ALA is a mandatory consideration for anyone with diabetic nerve pain. For others, it's a powerful antioxidant that supports blood sugar and general cellular health.

References

  1. RCTMetabolic syndromePubMed
  2. Meta-analysisMetabolic syndromePubMed
  3. ReviewCognitive declinePubMed

Sources for this page include published meta-analyses, systematic reviews, and NIH dietary supplement fact sheets. All claims reflect the evidence as of early 2026.

This is not medical advice. Consult your healthcare provider before starting any supplement, especially if you take medications.