L-carnitine and CLA (Conjugated Linoleic Acid) are popular supplements known for their role in boosting metabolism and supporting fat loss. L-carnitine helps transport fatty acids into cells to be burned for energy, while CLA is a naturally occurring fatty acid that may help reduce body fat and improve body composition by promoting fat loss and preserving lean muscle. These products come in various forms and flavors, offering versatility for those looking to enhance their fitness and weight management goals.