Toxic nephropathy is a disorder whose primary feature is impairment of the normal functions of the kidney. The clinical manifestations of toxic nephropathy vary from a mild reduction in renal function to hematuria, proteinuria, and urolithiasis to a severe progressive toxicity culminating in end-stage renal disease. Although it is commonplace for adolescents to use supplemental treatments such as natural medicines and over-the-counter (OTC) analgesics, they do not often reveal the use of such treatments to physicians, nor do they fully understand their potential adverse effects. This article reviews the nephrotoxic effects of OTC analgesics, natural medicines, and illicit drugs.