Acetyl-L-Carnitine
ALCAR
Amino-acid derivative (not a peptide) involved in fatty-acid transport, with modest human data.
Not FDA-approved. Dietary supplement (ALCAR). Levocarnitine (Carnitor) is FDA-approved for deficiency. This page describes research and public discussion; it is not a recommendation to use.
Overview
Carnitines shuttle long-chain fatty acids into mitochondria. Acetyl-L-carnitine is widely sold as a supplement; injectable L-carnitine (levocarnitine) is FDA-approved for carnitine deficiency.
Mechanism of action
Supports carnitine palmitoyltransferase–mediated fatty-acid transport for β-oxidation and donates acetyl groups.
Benefits & evidence ratings
Dosing
Doses show what has been studied or discussed — not guidance. Always follow your prescriber.
| Source | Dose | Frequency | Duration | Route |
|---|---|---|---|---|
Supplement trials B Human clinical data | 1–3 g/day in divided doses | Daily | 8–52 weeks | Oral |
Carnitor injection label (deficiency) A Established / approved | Per weight, physician-directed | Varies | Varies | IV |
Clinical trials & studies
- Review2016Effect of L-carnitine supplementation on weight loss: meta-analysis (Obesity Reviews)
Modest reductions in body weight and BMI.
Safety
Side effects
- Nausea, GI upset
- Fishy body odour
- Agitation in some users
Contraindications
- Hypothyroidism (may interfere with thyroid hormone)
- Seizure history (caution)
Interactions
- Warfarin/acenocoumarol — possible increased INR
- Thyroid hormone
Long-term safety
Generally well tolerated; possible TMAO increase with chronic L-carnitine intake.
Regulatory status
Supplement / OTC
Dietary supplement (ALCAR). Levocarnitine (Carnitor) is FDA-approved for deficiency.
FAQ
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