Oral Vs. Injectable L Carnitine Weight Wise Weight Loss Center LEVOCARNITINE INJECTION, USP1 g per 5 mL vial and 4 g per 20 mL vialFOR INTRAVENOUS USE ONLYRx Only What is L Carnitine, L Carnitine is an amino acid that plays a role in energy production and fat metabolism. Its found in foods like red meat, fish, and dairy, and also available as a supplement., L Carnitine Injection vs. Oral Supplements: Which is More Effective? Katalyst Wellness