L Carnitine is Underrated. New Meta Review Reminds Us Why. Acetyl L Carnitine vs L Carnitine: 4 Key Differences Momentous Early research into L carnitine was often cited as underwhelming, showing negligible changes in muscle carnitine content and fat loss outcomes. However, these findings may have been limited by a short study window l Carnitine and synbiotic co supplementation: beneficial effects on metabolic endotoxemia, meta inflammation, and oxidative stress biomarkers in obese patients: a double blind, randomized, controlled clinical trial Food & Function (RSC Publishing) Frontiers Ameliorating effects of L carnitine and synbiotic co supplementation on anthropometric measures and cardiometabolic traits in women with obesity: a randomized controlled clinical trial