RSP Nutrition Liquid L-Carnitine Weight Management Formula, Berry, 16 fl oz, 31 Servings. RSP Liquid L-Carnitine is an amino acid supplement that promotes stimulant-free metabolism enhancement, fat burning, healthy body composition, and enhanced performance; all in a convenient liquid form for rapid absorption and maximum efficacy. Liquid L-Carnitine helps facilitate the transfer of fatty acids, resulting in additional energy, muscle growth, fat loss and reduction of fatigue. Our formula works to improve metabolism, muscle preservation and supports an all-natural increase in athletic performance and endurance. RSP Liquid L-Carnitine is a safe alternative to typical fat burners and diet pills. It has been created for maximum potency and efficacy, without the use of stimulants.