Our bodies send us important signals, and sometimes the smell of our breath or skin can indicate an underlying health issue. For instance, fruity breath could suggest diabetes, while rotten meat breath L carnitine: Science Backed Benefits, Risks, and More Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications Acetyl L Carnitine (500mg) NutraBio Brands Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish.