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 effective for both fat loss and athletic performance. However, oral L carnitine has lower bioavailability and can be harmful at high doses, so it should be avoided. , Even cardiologists Pharmacokinetics of L Carnitine Clinical Pharmacokinetics Springer Nature Link Gorilla Mode AR Androgen Receptor Upregulator Low Bioavailability and High TMAO Production: Novel Insights Into Acetylcarnitine and Carnitine Metabolism KrimsDavis 2025 Molecular Nutrition & Food Research Wiley Online Library