L-Carnitine

Why Researchers Study L-Carnitine

L-Carnitine (levocarnitine) is the biologically active form of carnitine, a small amino-acid derivative synthesised endogenously from lysine and methionine. Its central function is the carnitine shuttle, the transport route by which long-chain fatty acids reach the mitochondrial matrix for beta-oxidation. Because that shuttle is a rate-limiting step of long-chain fatty-acid oxidation, carnitine is studied in models of fuel selection and mitochondrial metabolism.

Mechanism of Action

Long-chain fatty acids cannot cross the inner mitochondrial membrane on their own. Carnitine palmitoyltransferase I (CPT1) attaches the fatty acyl group to carnitine, carnitine-acylcarnitine translocase (CACT) moves the resulting acylcarnitine across the membrane, and CPT2 hands the acyl group back to CoA inside the matrix for beta-oxidation.

Beyond transport, carnitine buffers the mitochondrial acetyl-CoA/CoASH ratio by exporting excess acetyl groups as acetylcarnitine, freeing CoA for pyruvate dehydrogenase and the TCA cycle.

Handling & Storage

Supplied as a 500 mg/ml aqueous solution in a 10 ml vial (5000 mg total). Store refrigerated at 2-8 °C, protected from light, and do not freeze. Allow the vial to reach room temperature before opening.

For research purposes only. Not for human consumption.