N-acetyl leucine

amino-acidderivative

At a glance

Best for
people with cerebellar ataxia or specific neurological disorders, under medical care
Typical dose
Commonly ~3–5 g/day in divided doses in studies
Time to effect
Days to weeks
Main caution
Use for serious neurological disease should be medically supervised
Evidence strength: Moderate for Niemann-Pick C and cerebellar ataxia; unproven for general use

What is it

N-acetyl-leucine is an acetylated form of the amino acid leucine that crosses into the brain and acts on cerebellar and vestibular pathways. It has been studied as a treatment for inherited and acquired neurological disorders affecting balance and coordination, and the L-enantiomer (levacetylleucine) is now an approved drug for Niemann-Pick disease type C. As a supplement, robust evidence is confined to specific neurological conditions rather than general use.

Is it worth it for you?

Worth considering if…

  • You have Niemann-Pick type C or a cerebellar ataxia and a clinician recommends a trial
  • You have acute vestibular vertigo and want a studied option under guidance

Probably skip if…

  • You are healthy and seeking general cognitive or energy benefits
  • You want to self-treat a serious neurological condition without a clinician
  • You expect it to act like ordinary leucine for muscle

Evidence at a glance

GoalEvidenceEffectBest fitTime
niemann-pick type c and inherited cerebellar ataxiasGoodModest improvement in ataxia scorespatients with Niemann-Pick type C or genetic cerebellar ataxias under specialist careDays to weeks
acute vertigo and vestibular disordersMixedUncertainpeople with acute vestibular vertigoDays

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

niemann-pick type c and inherited cerebellar ataxias

Disease adjunct
Good

Randomized and open-label trials of the L-enantiomer show improvements in standardized ataxia and functional scales in Niemann-Pick type C, leading to regulatory approval of levacetylleucine. Smaller studies suggest benefit in some inherited cerebellar ataxias. Evidence is strongest in these specific genetic conditions rather than ataxia generally.

Effect size: Modest improvement in ataxia scores
Time to effect: Days to weeks
Best fit: patients with Niemann-Pick type C or genetic cerebellar ataxias under specialist care
Less likely: people without a diagnosed neurological disorder

Bottom line: Genuinely improves ataxia symptoms in Niemann-Pick C and some cerebellar ataxias under medical care.

acute vertigo and vestibular disorders

Supplement benefit
Mixed

Acetyl-leucine has a long history of use for acute vertigo in some countries and shows benefit in observational and small studies. Higher-quality randomized evidence is limited and mixed. Its vertigo use is plausible but less firmly established than its role in cerebellar ataxia.

Effect size: Uncertain
Time to effect: Days
Best fit: people with acute vestibular vertigo
Less likely: people with chronic non-vestibular dizziness

Bottom line: May help acute vertigo, but controlled evidence is limited and inconsistent.

Evidence is mixed

Traditional clinical use and small studies are positive, but rigorous randomized vertigo trials are scarce.

How to take it

Typical dose
~3–5 g/day in divided doses, as used in clinical studies
Higher studied dose
Up to ~5 g/day in some ataxia trials
Timing
Divided through the day, separated from meals in some protocols
With food
Often taken away from food per study protocols
Split dosing
Typically split into 2–3 daily doses
How long to try
Use under medical supervision with periodic reassessment

What to track

  • Balance, gait and coordination
  • Vertigo frequency and severity
  • Tolerability and side effects

Safety

Common side effects

Generally well tolerated, Occasional mild GI upset, Fatigue or headache

Who should avoid it

  • Pregnant or breastfeeding people
  • People self-managing serious neurological disease without a clinician

Pregnancy & breastfeeding

Avoid unless prescribed; pregnancy safety is not established.

Choosing a product

Look for

  • Enantiomer specified (L-/levacetylleucine vs DL)
  • Stated dose per serving
  • Pharmaceutical-grade purity and third-party testing

Be skeptical of

  • General nootropic/brain booster
  • Builds muscle like leucine
  • Cures neurological disease

References by claim

niemann-pick type c and inherited cerebellar ataxias

  • Bremova-Ertl et al., 2022PMC (2022) link
  • Fields et al., 2023PMC (2023) link

acute vertigo and vestibular disorders

  • Vanderkam et al., 2019PubMed (2019) link

Track N-acetyl leucine with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Evidence-based·Last reviewed May 30, 2026·Evidence current as of May 30, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.