GlaxoSmithKline is a leading British pharmaceutical company with headquarters in Brentford, London. It was established in 2000 through the merger of Glaxo Wellcome and SmithKline Beecham and is now one of the world’s largest pharmaceutical companies by market capitalisation. GSK is split into three major divisions: pharmaceutical products, vaccines and consumer healthcare. Among these, some of its products are included in the WHO’s list of essential medicines used to treat conditions such as cancer and autoimmune diseases, HIV/AIDs and bacterial infections. The company has manufacturing, research and development centres in 36 countries, and employs almost 100,000 people in 150 countries. GSK stock is listed on the London Stock Exchange and a constituent of the FTSE 100 index. Start spread betting or trading CFDs on our GlaxoSmithKline share price.