Liquid L Carnitine Citrus L Carnitine: Everything You Need to Know 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. Amazon.com: FRONTLINE FORMULATIONS L Carnitine, Stimulant Free, Enhances Energy and Metabolism, Increased Energy and Endurance, Amazing Flavors, Veteran Owned and Operated (Blue Coconut Lemonade) : Health & Household The Role of L Carnitine in Kidney Disease and Related Metabolic Dysfunctions Your urine's smell can reveal a lot about your health. A strong ammonia like odor could indicate kidney stress, while a fruity scent may suggest ketones. Sweet smelling urine might point to diabetes risk,