 This case report highlights the potential risk of using Orlistat as a weight loss medication in patients with pre-existing renal impairment. The patient experienced severe oxalate crystal deposition in the kidneys due to the high levels of oxalates in her system from taking Orlistat. This resulted in acute kidney injury, requiring multiple dialysis sessions before her kidney function improved. It is important to note that this patient had been taking Orlistat for several weeks prior to developing AKI, suggesting that the drug may have contributed to the development of the condition. Additionally, the patient's use of a proton pump inhibitor further increased the amount of oxalates entering her body, leading to the severity of her symptoms. This case serves as a reminder that certain medications can cause serious side effects when taken by those with pre-existing renal impairment. This article was offered by Youshae Humayun, Kenneth Seaball, Jack R. Lewin and others.