l-carnitine fishy odor trimethylamine side effect body Did You Know? Some people report FMO3 (Metabolism) Gene Report -
Description
It's about converting what we eat into usable energy, particularly fats

Why Multiple Forms of Carnitine Are Combined

(PubMed) Sethumadhavan S, Chinnakannu P
Hypothyroidism, by contrast, happens when your thyroid gland doesn't make enough thyroid hormones
doi: 10.1016/j.bbalip.2012.10.007