L Carnitine injection is recommended at 1 ampule every 2 3 days for best results. The L Carnitine is taken intravenously either by normal injection or using a butterfly needle. After taking this L Carnitine, you L Carnitine Fat Burning Shotsbecause pictures speak louder than words! These little shots are packed with powerful benefits: Supports weight management Helps reduce body fat Converts fat into energy Carnitine: Top 3 Anti Aging Benefits of This Super Nutrient The Science of Carnitine: How It Works and Why It Matters L carnitine is a naturally occurring amino acid structure that is made in the human brain, liver, and kidneys. L carnitine plays a critical role in energy production, as it converts fat into energy.