Subcutaneous Injection: What It Is and How to Give One L Carnitine Injection (Intramuscular): How It Works & What to Expect Mesotherapy Cocktails, Exosomes Regenerative Skin Boosters Compounded Carnitine (L) Injection Empower Pharmacy 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 How to Self Administer Subcutaneous & Intramuscular Injections