YSS Laboratories Co., Inc. is a wholly-owned Filipino company which was established in 1954 by the late owner Mr. Yao Shiong Shio. It was a licensee of the products of Merck, Sharpe and Dohme Company in the USA and started manufacturing Penicillin G Sodium Injection and Streptomycin Injection for the said company.It was transferred in 1976 to its present site at United Nations Ave., Manila and became a licensee for repacking of imported MSD products being distributed by The Cathay Drug Company locally.YSS Laboratories also expanded its activities into product development of generic drug and manufacturing of veterinary products. It also opened its doors of sterile filling facility as toll manufacturer to other clients who wishes their products to be manufactured locally.