L Carnitine & Muscle Soreness Relief Advanced Molecular Labs Low bioavailability = no meaningful effect, Oral L carnitine has very low bioavailability., Most of it isnt absorbed, and even what is doesnt increase fat burning., ., ., ., ., #workout #malayalam What is L Carnitine, and what does it do? Fit Nutrition Australia 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