Limited evidenceBrain & cognition

Idebenone

A synthetic CoQ10 analogue that is a licensed drug for a rare mitochondrial eye disease. For the memory and general 'mitochondrial support' claims it is sold under, the trial record is negative.

Evidence last reviewed: August 2026

What the science says

No benefit for Alzheimer's disease Moderate evidence
A multicentre randomized double-blind trial found that idebenone failed to slow cognitive decline in Alzheimer's disease at any of the doses tested. Earlier comparative work against tacrine was inconclusive, and no trial supports use as a memory enhancer in healthy adults.
Vision in Leber hereditary optic neuropathy Moderate evidence
A systematic review and meta-analysis found that idebenone improved the chance of clinically relevant visual recovery in Leber hereditary optic neuropathy compared with untreated controls. This is a prescription indication at 900 mg/day under specialist care, not a supplement use.
Respiratory function in Duchenne muscular dystrophy Moderate evidence
The DELOS phase 3 randomized placebo-controlled trial in patients not using glucocorticoids reported a slower decline in peak expiratory flow over 52 weeks. Again a supervised drug indication rather than a nootropic effect.

Dosage & safety

Studied doseClinical trials used 900 mg/day (300 mg three times daily) in eye and muscle disease and 120–360 mg three times daily in the negative Alzheimer's trials. Supplement labels typically give 45–150 mg/day, a dose no study supports for cognition.

SafetyCommon effects in trials were diarrhoea, nasopharyngitis and back pain; liver enzymes may rise. It is a prescription medicine in several countries and its legal status as a supplement varies. Do not use as a self-directed treatment for a diagnosed mitochondrial or neurological disease, and avoid in pregnancy and breastfeeding.

Scientific references

Idebenone treatment fails to slow cognitive decline in Alzheimer's disease
Thal LJ, Grundman M, Berg J — Neurology, 2003
Therapeutic benefit of idebenone in Leber hereditary optic neuropathy: a systematic review and meta-analysis
Ribeiro PVZ, Pari Mitre L, Gauza MM — Ophthalmic Genet, 2025
Efficacy of idebenone on respiratory function in patients with Duchenne muscular dystrophy not using glucocorticoids (DELOS): a double-blind randomised placebo-controlled phase 3 trial
Buyse GM, Voit T, Schara U — Lancet, 2015

Where to buy

View on iHerb

Referral link — this site may earn a commission on purchases.

Related in Brain & cognition

Vitamin B2 (Riboflavin) Moderate evidence
Choline Moderate evidence
Magnesium L-Threonate Limited evidence
Phosphatidylserine Limited evidence
Lecithin (Phosphatidylcholine) Limited evidence
Agmatine Sulfate Limited evidence