L Carnitine Injection vs. Oral Supplements: Which is More Effective? Katalyst Wellness L Carnitine Linus Pauling Institute Oregon State University Role of L carnitine in exercise training: Anti inflammatory, antioxidant, and metabolic interactions ScienceDirect Oral Vs. Injectable L Carnitine Weight Wise Weight Loss Center 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.,