L carnitine supplements bioavailability is very less and according to some studies it takes 8 to 12 weeks for for loss results, so if you decide to supplement with oral L carnitine do take it in The bright and the dark sides of L carnitine supplementation: a systematic review Journal of the International Society of Sports Nutrition Springer Nature Link Low Bioavailability and High TMAO Production: Novel Insights Into Acetylcarnitine and Carnitine Metabolism KrimsDavis 2025 Molecular Nutrition & Food Research Wiley Online Library Carnitine: Genetic Variants Affecting Mitochondrial Energy and Health Full article: L Carnitine conjugated nanoparticles to promote permeation across bloodbrain barrier and to target glioma cells for drug delivery via the novel organic cation carnitine transporter OCTN2