FAT BURNERS COMPLEXIS USUALLY contain 6 key ingredients: 
L-Carnitine, Choline, Inositol, Betaine, Methionine and Chromium Picolinate. These 6 ingredients act by both increasing your body’s metabolism to burn fat plus by aiding your body in removing and transporting fat out of your body and increasing synthesis of muscle protein. 

Lipotropics prevent an abnormal accumulation of fat in the liver. They are methionine, choline, inositol and betaine. Lipotropics increase production of lecithin by the liver thereby helping to keep cholesterol more soluble and lessening deposits in blood vessels. They also detoxify amines, which are by-products of protein metabolism. 

Methionine is a lipotropic amino acid, which reduces fat and aids in lowering cholesterol. It can be substituted for choline that aids in reducing liver fat (lipotropic agent). It detoxifies amines, which are by-products of protein metabolism. Methionine seems to act as a catalyst for choline and inositol thus speeding up their function. A deficiency of Methionine may lead to fatty degeneration and cirrhosis of the liver. 

Choline is another lipotropic (fat emulsifier). It aids in emulsifying cholesterol so that it doesn’t deposit on arterial walls. It works well with inositol to utilize fats and cholesterol, and it also works well with methionine in detoxifying amines, which are by-products of protein metabolism. 

Inositol metabolizes fats and cholesterol and aids in transporting fat in the blood system. Thus it is an aid in the redistribution of body fat. It helps to lower cholesterol levels. 

Betaine (trimethylglycine) is a great source of methyl groups. Methyl groups can deactivate harmful substances in the body and convert them to helpful substances. High levels of homocysteine can increase the risk of heart disease. It is relatively easy to lower homocysteine levels by taking methyl rich betaine, converting it to helpful methionine, a beneficial amino acid. 

Athletes have long used l-Carnitine for longer workout periods. It is used in fat burners because it helps in converting stored fat into energy. It can also help in controlling hypoglycemia and thereby benefits diabetics. A deficiency can cause impairment of heart tissue. Carnitine has only been recently noted as an important amino acid (the L-form only) essential to our health. L-Carnitine is known to transport fatty acids to the innermost section of the mitochondria (the powerhouse of the cell), where they are used to create energy resource - adenosine triphosphate (ATP). Studies have shown that carnitine deficiency lowers ATP levels in various tissues and increases the susceptibility to fatigue during strenuous physical activity. Carnitine has been shown to reduce blood triglycerides and cholesterol levels by increasing fat utilization: At the same time, it can raise the HDL ("good") portion of the cholesterol, which reduces the risk of cardiovascular disease. Carnitine is stored primarily in the skeletal muscles and heart, where it is needed to transform fatty acids into energy for muscular activity. Many athletes have noted an increased endurance muscle building effect with proper carnitine supplementation. 

Chromium picolinate is the most absorbable form of chromium. Chromium is a rare metal and probably 99% of the American population do not get enough chromium in their diet. A higher sugar diet can increase the excretion of chromium. Researchers believe that a chromium deficiency leads to Type II diabetes. It is a good remedy for elevating blood cholesterol and triglyceride. Chromium works well in combination with inositol to lower LDL and increase HDL levels. Research has shown that chromium picolinate can burn fat and enhance muscle even without exercise or a special diet. The average people taking 6 tablets per day will loss 1 kg (approximately 2 pounds) per week with no diet modifications. Lipotropic fat burner tablets can reduce your body fat levels without having to practice starvation dieting or similar means.