Compound or practice · Supplement
Acetyl-L-Carnitine (ALCAR)
The brain-penetrant carnitine — real evidence for diabetic neuropathy, softer signals for mood and aging cognition.
- Overall grade
- Grade B
- Last revised
- 3
- graded outcomes
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
2 at grade B · 1 at grade C — 3 graded rows
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- Diabetic neuropathy painEvidence grade B
Best use
Moderatehigh
- Depression (older adults)Evidence grade B
Adjunct
Smallmixed
- Cognition (MCI/aging)Evidence grade C
Modest
Smallmixed
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Thin evidence: Cognition (MCI/aging) (grade C).
- Studies disagree: Depression (older adults) (mixed agreement).
Interactions
Documented pairings with supplements and medicines. A medicine on this list is a conversation for whoever prescribes it.
L-CarnitineWorks together
Overlapping carnitine pool; ALCAR is the more brain-penetrant form.
The evidence in words
What it is
Acetyl-L-carnitine is an acetylated form of carnitine that crosses the blood-brain barrier better than plain L-carnitine.
How it works
It shuttles fatty acids into mitochondria for energy, donates acetyl groups for acetylcholine synthesis, and has neuroprotective/antioxidant actions.
What the evidence shows
ALCAR has good evidence for reducing pain in diabetic peripheral neuropathy, and moderate evidence for depressive symptoms (especially in older adults) and for cognition in mild impairment. Benefits in healthy young people are less clear.
Safety & interactions
Generally safe; can cause GI upset, and, like carnitine, may raise TMAO. Mildly stimulating for some — take earlier in the day. L-Carnitine — Overlapping carnitine pool; ALCAR is the more brain-penetrant form.
Bottom line
A legitimate option for diabetic neuropathy and a reasonable adjunct for mood/aging cognition; less compelling as a general nootropic for the young and healthy.
Goes with
- L-CarnitineOverlapping carnitine pool; ALCAR is the more brain-penetrant form.Evidence grade C
Related reading
Entries that share this one's tags or conditions.
- Acetyl-L-Carnitine (ALCAR) for Cognition (MCI/aging)Evidence grade C — ModestEvidence grade C
- Acetyl-L-Carnitine (ALCAR) for Depression (older adults)Evidence grade B — AdjunctEvidence grade B
- Acetyl-L-Carnitine (ALCAR) for Diabetic neuropathy painEvidence grade B — Best useEvidence grade B
- Acetyl-L-Carnitine (ALCAR): side effects, safety & interactionsGenerally safe; can cause GI upset, and, like carnitine, may raise TMAO. Mildly stimulating for some — take earlier in tEvidence grade B
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.