Alpha-Lipoic Acid

ALA · Thioctic Acid

Snapshot

Indications	Contraindications
Diabetic neuropathy symptoms¹ Inflammatory markers^2–6 Glycemic markers^{3, 6} Sperm motility^{7, 8} Burning mouth syndrome^9–12 PCOS during IVF/ICSI¹³	Insulin autoimmune syndrome¹⁴

Alpha-lipoic acid (ALA) is a compound the body makes, and it also occurs in foods such as red meat, spinach, and broccoli¹⁴. It acts as a mitochondrial antioxidant that restores reduced glutathione and other antioxidants¹⁵. Supplementation is used for diabetic neuropathy symptoms and for glycemic and inflammatory markers, and for sperm quality in male infertility, burning mouth syndrome, and polycystic ovary syndrome.

In diabetic neuropathy, a meta-analysis of oral trials found improved symptom scores versus placebo, though pain, vibration sense and nerve conduction did not improve¹. Meta-analyses also report lower inflammatory markers, though results varied widely between studies^{2, 3}. Products are sold as capsules, tablets, and powders, including racemic and R-enantiomer forms, with more than 51,000 products listing alpha-lipoic acid; see Form comparison.

The most consequential caution is hypoglycemia, including insulin autoimmune syndrome, which was the most frequent serious event in a spontaneous-reporting analysis and which Memorial Sloan Kettering links to genetically predisposed individuals¹⁴. Health Canada labels ask for a practitioner's advice before use in diabetes¹⁶.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

79 sources, 67 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources