The present invention relates to an injectable composition for topical fat reduction without pain, edema, and side effects, and a method for preparing the same and, more specifically, to an injectable composition for topical fat reduction, wherein the injectable composition contains a particular mixing ratio of glycocholic acid (or a salt thereof) or taurocholic acid (or a salt thereof) and phosphatidylcholine (PPC), and thus causes no pain, edema, and side effects, such as necrosis of muscle cells, fibroblasts, vascular endothelial cells, besides adipocytes, anesthesia of a site of administration, extensive swelling, erythema, hardening, abnormal sensation, nodules, itching, burning sensation, nerve damage, and aphagopraxia, and to a method for preparing the composition. A DCA single injection, which has been known as an existing injection for topical fat reduction, or a composition of a PPC injection mixed with DCA as a solubilizer, is accompanied by pain and side effects, such as anesthesia, extensive swelling, topical edema, erythema, hardening, abnormal sensation, nodules, itching, burning sensation, and aphagopraxia, due to necrosis necessarily caused by lysis of even fibroblasts, vascular endothelial cells, and muscle cells, besides adipocytes, so that patients complain of pain, discomfort, and anxiety, and show low drug compliance, but the injection for topical fat reduction of the present invention has an excellent composition, which improves the quality of lives of patients and increases the drug compliance since the preparation is safe and stable and has excellent lipolysis and adipocytic apoptosis inducing effects, selectively to only adipocytes, leading to no side effects described above.
