Oops, I misspelled L-carnitine. Anyway, this is the definition of L-carnitine:
L-Carnitine is not an amino acid in the strict sense (it is not used as a neurotransmitter or in protein synthesis), however L-Carnitine bears many resemblances to amino acids and is usually grouped under this heading. L-Carnitine (the "L" refers to its chemical polarity) is used by the body to transport long chain fatty acids to the mitochondria in your cells, where they are burned for energy. Since this fat burning is such a major source of muscular energy, deficiencies in L-Carnitine are manifested as low energy levels and muscular weakness. L-Carnitine deficiencies can also appear as mental confusion or cloudiness, angina (heart pain) and weight gain.
So you see how it could aid in weight loss!
L-carnitine deficiencies can cause weight gain, and also it is necessary in the body's fat burning process. Too little of it, and weight loss can slow or stall altogether.
Starting at 500 mg. per day is a good idea. Then slowly increase it if needed until your weight loss picks up again. Some people need up to 8000 mg. per day, which can get quite expensive. The body can produce it's own L-carnitine if it has the right vitamins and minerals it needs to do so (B1, B6, C, and iron) and it is also found in meats, but for those with a considerable amount of weight to lose, often their bodies just can't produce enough to meet the demand, even with heavy vitamin supplementation, so the L-carnitine can help so much.