Background: Polygonum multiflorum (brand name Fo-ti) is a Chinese herb used as an antioxidant, antiaging agent, and liver and kidney health. It can cause acute hepatotoxicity and even death. There is no published data on the effectiveness of N-Acetyl cysteine (NAC) as a sole effective therapy. Case: A 23-year-old, healthy male, presented with jaundice and malaise of one-month duration. He had been taking a Chinese herb named Fo-Ti for 2 months. Physical examination revealed jaundice, with no stigmata of chronic liver disease. His laboratory results showed transaminitis with markedly elevated transaminases. Testings for infectious and autoimmune causes were unremarkable. The patient was admitted to the hospital. Fo-Ti was stopped and he was started on oral NAC as peroral protocol. He was discharged home on esomeprazole and oral NAC. He returned on the second day with worsening jaundice. He was readmitted and esomeprazole was discontinued. NAC was continued and his liver enzymes eventually improved. The supplement was tested by gas-chromatography mass spectrometry and measured the presence of emodin. Discussion: This case highlights the potential benefit of NAC as treatment of Polygonum multiflorum induced hepatotoxicity. The proposed mechanism of emodin induced liver injury is through disturbing glutathione metabolism in liver cells. This could explain the favorable response as NAC has the ability to replenish intracellular glutathione. Conclusion: Polygonum multiflorum use has been associated with severe and prolonged hepatotoxicity. Oral NAC should be considered in the treatment of these patients due to the favorable risk-benefit ratio.