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 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. Benefits of L carnitine injections are aplenty! This injection is a great way to boost your energy levels, help with weight management, and even promote healthy heart function. Studies show that Benefits of Carnitine, its usage, and the right dosage.