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Alpha-lipoic acid (ALA)

A rare antioxidant that works in both watery and fatty tissue — with genuine evidence for diabetic nerve pain.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Supplement guide

SupplementsAntioxidantsNervesBlood sugar

Alpha-lipoic acid is unusual: it’s soluble in both water and fat, and it regenerates other antioxidants (vitamins C and E, glutathione). Its best-supported use is a specific medical one.

Key takeaways

  • ALA is a dual-solubility antioxidant that recycles vitamins C, E and glutathione.
  • Best evidence: diabetic peripheral neuropathy — it reduces nerve pain, most strongly by IV, with oral 600 mg/day helping symptoms.1
  • May modestly improve blood-sugar control.
  • Dose 300–600 mg/day on an empty stomach; generally safe.

What it is

A short-chain fatty acid made in mitochondria and taken as a supplement. Its dual solubility lets it act throughout the cell and restore other antioxidants to their active form.

The evidence

Meta-analyses show ALA reduces the symptoms of diabetic peripheral neuropathy — pain, burning, numbness — with the clearest effect from intravenous dosing and reasonable benefit from oral 600 mg/day.1 It may also nudge blood glucose down.

Dose & how to use

300–600 mg/day, taken on an empty stomach (food lowers absorption). The R-form is more biologically active.

Safety & who benefits

Well tolerated; rarely, a benign drop in blood sugar or an insulin-autoimmune reaction. Most relevant for people with diabetic neuropathy or blood-sugar concerns.

Bottom line: a legitimately useful antioxidant for diabetic nerve pain — a targeted medical niche, not a general wellness pill.

References

Adult research summary for education, not a prescription. These are food supplements, not treatments for disease.

  1. Han T, et al. Alpha lipoic acid for symptomatic peripheral neuropathy in patients with diabetes: a meta-analysis of RCTs. pmc.ncbi.nlm.nih.gov

This article summarises nutrition science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.