L Carnitine Benefits for Male Erectile Dysfunction 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: Nutrition, pathology, and health benefits ScienceDirect When to take L carnitine: Dosage, forms, and side effects Amazon.com: Doctor's Best L Carnitine Fumarate Supplement for Men & Women L Carnitine Fumarate with Biosint Carnitines Capsules, Helps Convert Fat into Usable Energy, Non GMO, Gluten Free, Vegan 180 Veg Caps :