Acetyl-L-Carnitine (ALCAR)
Also called ALCAR, ALC
Acetyl-L-carnitine (ALCAR) is an acetylated form of L-carnitine that crosses the blood-brain barrier. Studies of ALCAR have looked at peripheral neuropathy, mild cognitive impairment and mental fatigue.
- Evidence
- BModerate evidence
- Studied dose
- 500-2000mg
- Safety score
- Verified references
- None yet, sources being re-verified
How it is thought to work
Acetyl-L-carnitine can donate an acetyl group for acetylcholine synthesis. It also transports long-chain fatty acids into mitochondria for beta-oxidation.
Where to buy Acetyl-L-Carnitine (ALCAR)
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| Vendor | Product | Size | Price | Per unit | Buy |
|---|---|---|---|---|---|
| Amazon |  Nutricost Acetyl L-Carnitine (ALCAR) 500mg, 180 Capsules | - | On Amazon | - | Check price on Amazon Ad |
| iHerb | Nutricost, Acetyl L-Carnitine, 500 mg, 30 Capsules | - | about $9.44 at iHerb (as of 24 September 2026) | - | Shop Ad |
| iHerb | NOW Foods, Acetyl-L Carnitine, 750 mg, 90 Tablets | - | about $23.06 at iHerb (as of 24 September 2026) | - | Shop Ad |
| iHerb | Source Naturals, Acetyl L-Carnitine, 500 mg, 120 Tablets | - | about $23.83 at iHerb (as of 24 September 2026) | - | Shop Ad |
What the studies found
| Claimed benefit | Grade | Basis |
|---|---|---|
| Cognitive function in mild cognitive impairment | B | Multiple RCTs and meta-analyses show consistent benefit in age-related cognitive decline. |
| Reduced mental fatigue | B | Source being re-verified |
| Peripheral neuropathy | A | Graded A, but no verified study is cited for this claim yet.Strong evidence in diabetic and chemotherapy-induced peripheral neuropathy. |
Each benefit is graded on its own; a substance can have strong evidence for one effect and little for another. What the grades mean.
Dose and timing
Doses used in the research on file, taken as 1-2 doses. Not a recommendation.
Logarithmic time scale. Individual metabolism varies.
Safety and interactions
| Recorded side effect | How often | Severity |
|---|---|---|
| Fishy body odor | uncommon | mild |
| GI upset | rare | mild |
Side effects in detailRecorded interactionsInteraction checker
History
The acetylated form of L-carnitine was developed in Italy in the 1970s and has been studied in European clinical literature for cognitive decline, fatigue and diabetic neuropathy. Liu and Ames 2002 examined it with alpha-lipoic acid in mitochondrial decay.
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Sign in to reviewAcetyl-L-Carnitine (ALCAR): quick answers
- How strong is the evidence for Acetyl-L-Carnitine (ALCAR)?
- The overall grade on file is B (moderate). 3 claimed benefits are graded separately in the table above. 1 of the benefit grades of A have no verified study cited yet.
- What dose of Acetyl-L-Carnitine (ALCAR) has been studied?
- The range on file is 500-2000 mg (1-2 doses). It describes doses used in research, not a recommendation.
- How long does Acetyl-L-Carnitine (ALCAR) take to work and how long does it last?
- Listed onset: about 60 minutes. Listed half-life: about 4 hours. Individual metabolism varies.
- What are the side effects of Acetyl-L-Carnitine (ALCAR)?
- Recorded side effects: Fishy body odor (uncommon), GI upset (rare). Safety score 5/5.
Compared with other substances
Show 3Hide
| Comparison | Grade | Class |
|---|---|---|
| Acetyl-L-Carnitine (ALCAR) vs Alpha-GPC | A | Cholinergic |
| Acetyl-L-Carnitine (ALCAR) vs Huperzine A | A | Cholinergic |
| Acetyl-L-Carnitine (ALCAR) vs Alpha-Lipoic Acid | A | Neuroprotective |
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