L-Carnitine is an amino acid which is one of the building blocks of proteins. It does not interact with the sex hormones, but it does make thyroid less effective, which is the opposite of what you need to do for permanent weight loss. For weight loss, yes, you can lose weight initially, but when you go back to eating normally, you will gain the weight right back and your thyroid hormone will be less effective.
For permanent and long term weight loss, you must permanently change your eating habits. I speak from experience having lost over 100 pounds by eating a diet heavy on vegetables, with some fruits and even less meat bread and dairy.
For myself, weight loss is the single most feminizing part of my transition. There is gastric surgeries for those way overweight. Supplements such as L-Carnitine are not effective if you want to remain at a lower weight. You need to learn to eat in such a way as to maintain you ideal weight, and that means a permanent change in eating habits.
