One of the basic factors of weight loss is exercise. Substances that burn fat are activated during sports activity. By adding fat burners, you will achieve a higher concentration of burners and thus a higher efficiency of exercise.
The most well-known fat burner and energizer in one is L-carnitine, so it is sold separately, but is also added to complex fat burners.
Thermogenic fat burners work in such a way that they increase the heart's activity and blood flow to the blood vessels, thus increasing the temperature in the muscles, which is equivalent to more efficient fat burning. However, the basis of every weight loss is a balanced diet, exercise and without these two factors, even the best fat burner will not help you, so the most effective combination is exercise, diet and nutritional supplements.