L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe Injectable L Carnitine: What It Is, How It Works, and Who Should Use It Mesotherapy Cocktails, Exosomes Regenerative Skin Boosters The Role of L Carnitine in Kidney Disease and Related Metabolic Dysfunctions 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 Acetyl L Carnitine Should I use L Carnitine on rest days or just before workouts?