Will North Star L-carnitine rebound? L-carnitine, also called vitamin BT, is a kind of vitamin, which mainly comes from red meat such as mutton, beef and pork. The main physiological function of L-carnitine is to promote the conversion of fat into energy. A recent study by an American expert group on teenagers' weight loss shows that taking L-carnitine is of great benefit to weight loss: L-carnitine (vitamin BT) can increase the weight by as much as 1 1 times, and rarely rebound. L-carnitine is a vitamin derived from red meat such as beef and pork, and can also be synthesized by the human body itself. It is the best and safest nutrient to lose weight. Because it comes from food, the human body can synthesize a part of it, which is not diet pills or health products, so there are no side effects. L-carnitine is a component of an enzyme in the process of fat metabolism. It is an important nutrient similar to vitamins, which can promote the conversion of fat into energy, thus achieving the effect of losing weight.