Alpha-lipoic acid
Alpha-lipoic acid; thioctic acid
Vitaminoid and related nutrients
Aliases / common names
ALA; lipoic acid; thioctic acid; R-lipoic acid
Natural food sources
Small amounts in spinach, broccoli, tomatoes, organ meats and yeast; synthesized in mitochondria.
Main wellness functions
Cofactor in mitochondrial enzyme complexes; antioxidant network support and glucose-metabolism formulas.
Deficiency signs
No typical dietary deficiency syndrome; rare genetic lipoic-acid metabolism disorders exist.
Recommended intake
No official RDA/AI has been established. Follow product labels and professional advice when used for specific goals.
Excess intake effects
May cause nausea, reflux, rash, headache and low blood sugar; very high doses are unsafe.
Contraindicated / caution groups
Use caution with diabetes medicines, thyroid medicines, heavy alcohol use, thiamine deficiency, pregnancy and chemotherapy.
Common dosage forms
Capsules, tablets; racemic ALA or R-lipoic acid; sustained-release products.
Common product strengths
100-600 mg; R-lipoic acid often 100-300 mg.
Use precautions
Monitor blood glucose when combined with glucose-lowering therapy. Separate from minerals if stomach irritation occurs.
Supplement notes
Often confused with omega-3 ALA (alpha-linolenic acid); they are different nutrients.
This information is for general nutrition education and product reference only. It does not replace medical diagnosis, treatment or individualized dietary advice.