L Carnitine Dosage Guide: How Much Should You Take? L Carnitine Linus Pauling Institute Oregon State University Acetyl L Carnitine Injectable L Carnitine: What It Is, How It Works, and Who Should Use It Mesotherapy Cocktails, Exosomes Regenerative Skin Boosters 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