Amino acids
L-Carnitine
Fat oxidation
Fatty-acid transport into mitochondria; energy metabolism. Common dose 500–2000 mg.
What L-Carnitine does
L-Carnitine shuttles long-chain fatty acids across the inner mitochondrial membrane for beta-oxidation. The body synthesizes carnitine from lysine and methionine; vegetarians have lower body stores but rarely become deficient. Acetyl-L-carnitine (ALCAR) crosses the blood-brain barrier and has been studied for cognitive aging, peripheral neuropathy, and depression. A 2013 meta-analysis raised concern that gut bacteria convert carnitine to TMAO (a cardiovascular risk biomarker) — clinical significance for healthy supplement users is contested.
Food sources of L-Carnitine
Approximate L-Carnitine content per serving. Whole-food intake counts toward your daily total alongside any supplemental dose.
| Food | Serving | L-Carnitine |
|---|---|---|
| Beef (cooked) | 3 oz | 85 mg |
| Pork (cooked) | 3 oz | 25 mg |
| Cod (cooked) | 3 oz | 5 mg |
| Whole milk | 1 cup | 8 mg |
| Chicken breast (cooked) | 3 oz | 3 mg |
Signs of L-Carnitine deficiency
- ●Primary carnitine deficiency (genetic OCTN2 mutations): cardiomyopathy, hypoketotic hypoglycemia, muscle weakness
- ●Secondary deficiency in renal dialysis, valproate use, prematurity
- ●Vegetarian/vegan diets show lower stores but usually no clinical syndrome
Who needs more L-Carnitine
Groups and situations where L-Carnitine requirements rise or status commonly runs low:
- ●Hemodialysis patients (carnitine is dialyzed out)
- ●Long-term valproate or pivampicillin use
- ●Diabetic peripheral neuropathy (ALCAR has trial support)
- ●Older adults with fatigue and cognitive complaints (modest evidence)
How L-Carnitine appears on labels
Supplement labels list L-Carnitine under several names depending on the chemical form used. Any of these on an ingredients panel counts toward your L-Carnitine intake:
- l-carnitine
- carnitine
- acetyl-l-carnitine
- alcar
- acetyl l-carnitine
Best supplements for L-Carnitine
Top-scoring supplements in our catalog that list L-Carnitine on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Deep dive
For mechanism of action, dosing protocols, evidence grade, and interaction warnings on L-Carnitine, see the full encyclopedia entry:
Acetyl-L-Carnitine (ALCAR) encyclopedia entry →Research on L-Carnitine
Peer-reviewed studies in our research database that reference L-Carnitine. Each entry links to a detailed methodology review.
- Sima AA, Calvani M, Mehra M, Amato A, 2005 · Diabetes CareAcetyl-L-carnitine for the treatment of diabetic peripheral neuropathy: a long-term, randomised, double-blind, placebo-controlled study
- Montgomery SA, Thal LJ, Amrein R, 2003 · International Clinical PsychopharmacologyAcetyl-L-carnitine for the treatment of mild cognitive impairment and mild Alzheimer's disease: a meta-analysis of clinical trials
Frequently asked questions
What is the daily target for L-Carnitine?
What foods are highest in L-Carnitine?
What is the best form of L-Carnitine to supplement?
What are the signs of L-Carnitine deficiency?
Who is most at risk for low L-Carnitine?
Related amino acids
Track your full intake
Formulate's free web app aggregates L-Carnitine (and ~40 other nutrients) across every supplement in your stack — flagging underdoses, overlaps, and upper-limit overshoots in one view.
Track your intake free →Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Targets and upper limits are general adult reference values; individual needs vary by age, sex, pregnancy status, and clinical context.