Tong Ren Tang is a Chinese pharmaceutical company founded in 1669. It is now the largest producer of traditional Chinese medicine. The company headquarters are in Beijing, where they engage in both manufacturing and retail sales. It operates drug stores, predominantly in Chinese-speaking regions. Tong Ren Tang is considered one of the "Big 4" traditional Chinese medicine brands still in existence. The four companies include: Guangyuyuan, Guangzhou Chen Liji, Beijing Tong Ren Tang, and Hangzhou Hu Qing Yu Tang.