Alpha-lipoic acid is a potent antioxidant with strong evidence for diabetic neuropathy and moderate evidence for blood sugar control. It's both fat- and water-soluble — unique among antioxidants. Our research identifies significant interactions with diabetes medications and thyroid hormones.
Alpha-lipoic acid (ALA, thioctic acid) is an organosulfur compound synthesized in mitochondria. It functions as a cofactor for mitochondrial enzymes (pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase) and as a direct antioxidant that regenerates vitamins C and E, CoQ10, and glutathione. Its dual solubility allows it to work in both aqueous and lipid environments — no other antioxidant does this.
ALA exists as R-ALA (natural, biologically active) and S-ALA (synthetic). Most supplements contain racemic ALA (50:50 R/S). R-ALA is 2-4x more bioavailable but less stable and more expensive.
Additive blood sugar lowering → hypoglycemia risk
ALA may reduce conversion of T4 to T3; monitor thyroid levels
ALA may reduce cisplatin efficacy (antioxidant opposition)
ALA may lower blood sugar further in combination with alcohol
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Han T et al. A systematic review and meta-analysis of α-lipoic acid in diabetic neuropathy.
Ziegler D et al. Oral treatment with α-lipoic acid improves symptomatic diabetic polyneuropathy (SYDNEY 2 trial).
Bresciani E et al. Alpha-lipoic acid and insulin autoimmune syndrome.
Koh EH et al. Effects of alpha-lipoic acid on body weight in obese subjects.
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated: April 2026
Not medical advice. Based on published clinical research and systematic reviews.