L-Carnitine vs. Levocarnitine: Understanding the Difference

L-carnitine and levocarnitine are the same molecule.

• L-carnitine = the naturally occurring, biologically active isomer.
• Levocarnitine = the synthetic (pharmaceutical-grade) form of L-carnitine.

Both are identical in structure and function. The body synthesizes L-carnitine from lysine and methionine (requiring vitamin C, B6, niacin, iron). Dietary sources: red meat, poultry, fish, dairy.

Functions: Transports long-chain fatty acids into mitochondria for β-oxidation (energy production).

Supplemental uses: Primary/secondary carnitine deficiency, certain cardiovascular conditions, renal disease (dialysis), athletic performance (mixed evidence).

Levocarnitine advantages: Greater stability, longer shelf life, consistent purity—preferred in pharmaceuticals.

Dose: Typically 500–2000 mg/day. Consult a physician before supplementing, especially with thyroid, seizure, or anticoagulant medications.