Acetyl-L-Carnitine
Amino Acid ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Acetylated form of L-carnitine that crosses the blood-brain barrier for cognitive support.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Acetyl-L-Carnitine is an amino acid most often used for cognitive function, neuroprotection, energy. NutriStack rates the overall evidence as moderate. A typical adult dose is 500-1,500 mg daily, commonly taken as acetyl-l-carnitine hcl. This profile indexes 16 sources.
The bottom line
Evidence rating moderate. Most-documented uses: cognitive function, neuroprotection, energy. 16 sources indexed (2003–2024), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Crosses BBB and donates acetyl groups for acetylcholine synthesis. Supports mitochondrial function in neurons and enhances nerve growth factor activity.13,1
Dosing & protocol.
What it actually costs.
Real-world pricing across three quality tiers. Assumes Acetyl-L-Carnitine HCl.
Assumes 500-1,000 mg/day from goal dosage. Vendor basis: BulkSupplements powder, NOW/iHerb, Vitacost, and Amazon marketplace capsules. Updated 2026-05-28.
The same dose, as food.
How much you'd eat to match a supplemental dose.
Foods provide L-carnitine rather than acetyl-L-carnitine, so this is only a rough carnitine-based comparison.
Full safety detail.
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
7- 1Clinician guidelines for the treatment of psychiatric disorders with nutraceuticals and phytoceuticals: The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce.PMIDSarris J, Ravindran A, Yatham LN, Marx W, Rucklidge JJ, McIntyre RS et al. · World Journal of Biological Psychiatry · 2022
WFSBP/CANMAT guidelines found moderate evidence supporting acetyl-L-carnitine for depression, with recommendations for its use as an adjunctive treatment.
- 2A Meta-Analysis of the Efficacy of L-Carnitine/L-Acetyl-Carnitine or N-Acetyl-Cysteine in Men With Idiopathic Asthenozoospermia.PMIDWei G, Zhou Z, Cui Y, Huang Y, Wan Z, Che X et al. · American Journal of Men's Health · 2021
L-carnitine/acetyl-L-carnitine supplementation significantly improved sperm motility (progressive motility and total motility) in men with idiopathic asthenozoospermia.
- 3Acetyl-L-carnitine in painful peripheral neuropathy: a systematic reviewPMIDDi Stefano G, Di Lionardo A, Galosi E et al. · Journal of pain research · 2019
Di Stefano G, Di Lionardo A, Galosi E et al.. Acetyl-L-carnitine in painful peripheral neuropathy: a systematic review. Journal of pain research. 2019
- 4Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-AnalysisPMIDVeronese N et al. · Psychosom Med · 2018
Meta-analysis of 12 RCTs (791 participants) found ALC superior to placebo for depression; equally effective as fluoxetine and amisulpride for dysthymic disorder with fewer side effects.
- 5Acetyl-L-carnitine in the treatment of peripheral neuropathic pain: a systematic review and meta-analysis of randomized controlled trialsPMIDLi S et al. · PLoS One · 2015
ALC significantly reduced VAS pain scores in peripheral neuropathy patients; appeared more effective in diabetic vs non-diabetic neuropathy. Safe and well tolerated.
- 6Acetyl-L-Carnitine for the Treatment of Peripheral Neuropathic Pain: a Systematic Review and Meta-AnalysisSource linkedPMIDLi S, Li Q, Li Y et al. · Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research · 2014
- 7Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer's diseasePMIDMontgomery SA et al. · Int Clin Psychopharmacol · 2003
Meta-analysis showed significant advantage for ALCAR vs placebo in MCI and mild AD (effect size 0.201, 95% CI 0.107-0.295); benefit seen at 3 months and increased over time.
Randomized controlled trials
4- 8Acetyl-L-carnitine Slows the Progression from Prefrailty to Frailty in Older Subjects: A Randomized Interventional Clinical TrialPMIDMalaguarnera G, Catania VE, Bertino G et al. · Current pharmaceutical design · 2022
Malaguarnera G, Catania VE, Bertino G et al.. Acetyl-L-carnitine Slows the Progression from Prefrailty to Frailty in Older Subjects: A Randomized Interventional Clinical Trial. Current pharmaceutical design. 2022
- 9Acetyl-L-Carnitine to Enhance Nerve Regeneration in Carpal Tunnel Syndrome: A Double-Blind, Randomized, Controlled TrialPMIDCurran MWT, Morhart MJ, Olson JL et al. · Plastic and reconstructive surgery · 2019
Curran MWT, Morhart MJ, Olson JL et al.. Acetyl-L-Carnitine to Enhance Nerve Regeneration in Carpal Tunnel Syndrome: A Double-Blind, Randomized, Controlled Trial. Plastic and reconstructive surgery. 2019
- 10Acetyl-L-carnitine (ALCAR) to enhance nerve regeneration in carpal tunnel syndrome: study protocol for a randomized, placebo-controlled trialPMIDCurran MW, Olson J, Morhart M et al. · Trials · 2016
Curran MW, Olson J, Morhart M et al.. Acetyl-L-carnitine (ALCAR) to enhance nerve regeneration in carpal tunnel syndrome: study protocol for a randomized, placebo-controlled trial. Trials. 2016
- 11Acetyl-L-carnitine improves pain, nerve regeneration, and vibratory perception in patients with chronic diabetic neuropathy: an analysis of two randomized placebo-controlled trialsPMIDSima AA et al. · Diabetes Care · 2005
ALC treatment is efficacious in alleviating pain symptoms, improves nerve fiber regeneration and vibration perception in patients with established diabetic neuropathy.
Reviews & position papers
3- 12A Comprehensive Review of Safety, Efficacy, and Indications for the Use of Alpha-Lipoic Acid and Acetyl-L-Carnitine in Neuropathic PainPMIDAldendail CF, Chen P, Dibble HS et al. · Integrative medicine (Encinitas, Calif.) · 2024
Aldendail CF, Chen P, Dibble HS et al.. A Comprehensive Review of Safety, Efficacy, and Indications for the Use of Alpha-Lipoic Acid and Acetyl-L-Carnitine in Neuropathic Pain. Integrative medicine (Encinitas, Calif.). 2024
- 13Acetyl-L-Carnitine in Dementia and Other Cognitive Disorders: A Critical UpdatePMIDPennisi M et al. · Nutrients · 2020
ALC crosses BBB and donates acetyl groups for acetylcholine synthesis; supports mitochondrial function in neurons, enhances nerve growth factor activity, and exerts neurotrophic effects.
- 14Chronic acetyl-L-carnitine alters brain energy metabolism and increases noradrenaline and serotonin content in healthy micePMIDSmeland OB et al. · Neurochem Int · 2012
ALCAR supplementation increased brain noradrenaline and serotonin levels, consistent with its potential efficacy for depressive symptoms and mood support.
Reference material
2- 15Martí-Carvajal AJ, Gluud C, Arevalo-Rodriguez I et al.. Acetyl-L-carnitine for patients with hepatic encephalopathy. The Cochrane database of systematic reviews. 2019Source linkedPMID
- 16Hudson S, Tabet N. Acetyl-L-carnitine for dementia. The Cochrane database of systematic reviews. 2003Source linkedPMID
Common questions.
Quick answers about Acetyl-L-Carnitine, drawn from the data on this page.
What is Acetyl-L-Carnitine?
Acetylated form of L-carnitine that crosses the blood-brain barrier for cognitive support.
What is Acetyl-L-Carnitine used for?
Commonly cited benefits of Acetyl-L-Carnitine include: Cognitive function; Neuroprotection; Energy; Mood support. NutriStack rates the overall evidence as moderate.
What is a typical dose of Acetyl-L-Carnitine?
A typical adult dose of Acetyl-L-Carnitine is 500-1,500 mg daily. The commonly recommended form is Acetyl-L-Carnitine HCl. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Acetyl-L-Carnitine?
Reported side effects include restlessness, insomnia if taken late, gi upset. This is educational information; check with a healthcare professional before use.
How strong is the evidence for Acetyl-L-Carnitine?
NutriStack rates this as Moderate, meaning several aligned RCTs or one large RCT plus supporting reviews. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
Acetyl-L-Carnitine in NutriStack.
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