Nucleo Longevity
it

Alpha-lipoic acid (ALA)

alpha-lipoic acid · ALA · thioctic acid · R-ALA

A mitochondrial antioxidant promoted for nerves, blood sugar and aging.

TypeSupplement / dietary

The grade answers: What does the human evidence support for: Metabolic & nerve support?

Grade

C

Limited

The grade rates evidence quality — it is not advice to take or buy.

Class
Antioxidant / cofactor
Primary use
Metabolic & nerve support
Evidence strength
medium
Last reviewed
2026-07-01

Bottom line

Best evidence is for diabetic nerve symptoms and modest glucose effects — not aging. A legitimate metabolic supplement with a specific niche, oversold as an anti-aging antioxidant.

What the evidence says

Alpha-lipoic acid is both fat- and water-soluble, is a cofactor for mitochondrial enzymes, and can regenerate other antioxidants. Its strongest human evidence is for symptomatic relief of diabetic peripheral neuropathy (especially intravenous, with oral data weaker) and small improvements in insulin sensitivity and weight. There is no human longevity outcome evidence; the 'anti-aging antioxidant' framing is extrapolated from mechanism and animal work. Grade C: a real metabolic/neuropathy niche, unproven for aging.

Key studies

  1. [1]

    Alpha-lipoic acid for diabetic neuropathy · meta-analysis

    Symptom benefit, strongest with intravenous dosing.

    Open on PubMed ↗
  2. [2]
  3. [3]

    Alpha-lipoic acid antioxidant mechanisms (review) · review

    Basis for the (extrapolated) anti-aging claims.

    Open on PubMed ↗
See all studies on PubMed ↗

Mechanism

Acts as a cofactor for mitochondrial dehydrogenase complexes and as a redox-active antioxidant that can recycle vitamins C and E and support glutathione.

Safety

Generally well tolerated; can cause GI upset and, by lowering blood glucose, may add to the effect of diabetes medication (hypoglycaemia risk). Rare autoimmune reactions have been reported.

Dosage context

Trials commonly use ~300–600 mg/day (higher, IV, in neuropathy studies). The R-enantiomer is marketed as more active; evidence for superiority in practice is limited.

Examples of application

  • Taken ~300–600 mg/day, mainly relevant to diabetic nerve symptoms.
  • Can add to the glucose-lowering effect of diabetes medication.
  • Aging claims are extrapolated from mechanism, not outcomes.

From the field

ALA earns its place through diabetic-neuropathy data, then gets sold for aging on the strength of a mechanism. We grade it C and keep the niche and the hype separate.

Related molecules

Coenzyme Q10C
How we assign grades → Method