GNC Holdings, Inc., together with its subsidiaries, operates as a specialty retailer of health, wellness, and performance products. The company operates through three segments: U.S. and Canada, International, and Manufacturing/Wholesale. Its products include proteins, performance supplements, weight management supplements, vitamins, herbs and greens, wellness supplements, health and beauty products, food and drink products, and other general merchandise. The company also provides third-party contract manufacturing services. It sells its products under the GNC proprietary brands, as well as under third-party brands. As of December 31, 2018, the company had approximately 8,400 locations of which approximately 6,200 retail locations in the United States and franchise operations in approximately 50 countries. It sells its products through company-owned retail stores and its Website GNC.com, as well as third-party Websites; wholesale partnerships; and domestic and international franchise activities. GNC Holdings, Inc. has a strategic partnership with Harbin Pharmaceutical Group Holding Co., Ltd. and International Vitamin Corporation. The company was founded in 1935 and is headquartered in Pittsburgh, Pennsylvania.