There have recently been many advances in obesity treatment, including lifestyle modifications and pharmacological and surgical treatments. Specifically, pharmacological strategies have improved significantly. However, the history of the development of medications aimed at weight loss is complicated. The Federal Drug Administration (FDA) withdrew anti-obesity drugs such as fenfluramine, dexfenfluramine, and phenylpropylamine due to their unwanted side effects. Moreover, sibutramine was voluntarily withdrawn from the market and a new drug, rimonabant, has been suspended in the middle of a clinical trial due to unacceptable side effects. The FDA has approved four new anti-obesity drugs in recent years. Lorcaserin is a selective 5-hydroxytryptamine receptor 2c (5-HT2c) agonist. The pharmacological mechanism of action of this drug is similar to fenfluramine and dexfenfluramine, but lorcaserin is specific for 5-HT2c, which are located almost exclusively in the central nervous system and are not found in heart valves. Three phase 3 clinical trials for lorcaserin have been published recently; weight reduction was successful and no side effects involving the heart were found. Furthermore, the FDA has also approved phentermine/topiramate controlled-release (PHEN/TPM CR), which is composed of a combination of immediate-release phentermine and controlled-release topiramate. Weight reduction achieved with PHEN/TPM CR was demonstrated to be better than all other anti-obesity drugs. Lastly, the combination therapy bupropion/naltrexone activates proopiomelanocortin neurons and inhibits opioid-mediated negative feedback by synergism. Similar to liraglutide, a long-acting analogue of the hormone glucagon-like peptide-1, this treatment showed significant weight loss and metabolic improvements. However, in addition to its efficacy, clinicians should consider its side effects before use.