Acetyl-L-Carnitine · Acetyl-L-Carnitine (ALCAR)
Carnitine crossing into the brain; neurological support.
Short answer
Reasonable choice for brain-focused stacks, especially with alpha-lipoic acid.
Product and dose overview
Acetyl-L-Carnitine (Acetyl-L-Carnitine (ALCAR)) is a mitochondrial with evidence grade C, meaning it is backed by mixed or small human trials. We track 0 products containing Acetyl-L-Carnitine. The top-ranked product scores 0 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $0.00 per month.
What it is
A form of carnitine that crosses into the brain, unlike regular carnitine.
Why people take it
Small trials show benefits in diabetic neuropathy, age-associated depression, and cognitive function in older adults.
Our verdict
Reasonable choice for brain-focused stacks, especially with alpha-lipoic acid.
Structure & class
Acetylated L-carnitine, crosses BBB.
Mechanism & clinical data
Multiple trials in age-associated cognitive decline; effect sizes modest.
Pharmacokinetics
~4 hours.
Dose & forms
What to watch out for
Can be stimulating; take earlier in day.
Safety limits and interactions
When a product exceeds the UL or contains an ingredient with clinically significant interactions, a "Review advised" flag appears on its product page and links here.
Source: https://ods.od.nih.gov/factsheets/Carnitine-HealthProfessional/
Where this dose comes from
The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.
When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.
Regulatory status
Timeline
Regulatory events, evidence grade changes, and key research milestones for Acetyl-L-Carnitine, most recent first. Studies link to the paper; regulatory entries name and link the responsible authority.
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EU Court sharpens the bar for botanical health claimsA Court of Justice of the European Union ruling in April 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
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EU report identifies 117 supplement substances as potential health risksThe HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
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EU refuses to authorise health claim for L-carnitine and lipid metabolismCommission Regulation (EU) 2021/77 refused to authorise the health claim "L-carnitine contributes to normal lipid metabolism." EFSA concluded in January 2018 that a cause and effect relationship had not been established between L-carnitine consumption and normal lipid metabolism. All previously submitted L-carnitine health claims (energy production, fat burning, muscle recovery) were also rejected.
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EU Health Claims Regulation adoptedRegulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
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EU introduces the Novel Food RegulationRegulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 May 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
Landmark studies
Found in these products
All products in our catalog that contain Acetyl-L-Carnitine, ranked by our overall score. Ranking is editorial, never paid.
No products in our catalog contain this yet.
Buying guides and comparisons
Related ingredients
See all in Mitochondrial →Molecules in the same class, plus the actives most often formulated alongside Acetyl-L-Carnitine in our catalogue.
See Acetyl-L-Carnitine in context: the mechanism it acts through, the biomarker it moves, the products that dose it, and the trials that tested it.
View Acetyl-L-Carnitine on the Longevity Map →Frequently asked questions
What is Acetyl-L-Carnitine?
A form of carnitine that crosses into the brain, unlike regular carnitine.
What dose of Acetyl-L-Carnitine should I take?
The trial dose in published human studies is 1500 mg per day, with a range of 500 to 3000 mg per day. Always consult a qualified clinician before starting any supplement.
Is Acetyl-L-Carnitine safe?
NIH ODS explicitly states carnitine does not have an established UL. Doses around 3 g/day can cause GI effects and fishy body odor. Gut microbiota metabolize L-carnitine into TMAO (trimethylamine-N-oxide), which is associated with increased cardiovascular disease risk and all-cause mortality, more pronounced in meat-eaters than vegans/vegetarians.
What is the best Acetyl-L-Carnitine supplement?
We track 0 products containing Acetyl-L-Carnitine. The top-ranked product scores 0 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.
What is the evidence grade for Acetyl-L-Carnitine?
Acetyl-L-Carnitine has evidence grade C, meaning it is backed by mixed or small human trials. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.
Data verification
Evidence grades are reviewed when new human RCTs are published. Product counts update automatically as new products are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.