The two pharmaceutical companies, which have well-known names such as Advil and Tums, said Wednesday that the new company had annual sales of $ 12.7 billion.
The merger will bring together major Pfizer vendors such as Centrum and Caltrate with GSK's top brands, including Excedrin and Nicorette.
Headquartered in the United Kingdom, GSK (GSK) will own just over two-thirds of the joint venture, with the remainder held by the US Pfizer (PFE).
Following the merger, GSK said it intended to divide itself in two by spying on the new healthcare business and listing it in London within three years. GSK's remaining businesses will focus on the manufacture of prescription drugs and vaccines.
"Our goal is to create two exceptional, UK-based global companies," said GSK CEO Emma Walmsley in a statement.
GSK shares rose more than 7% after the announcement in London.
Pfizer intended to relieve its Consumer Health business and said last year that it could either sell the business completely or outsource it as a separately traded stock. Pfizer makes most of its billions from its central unit for prescription drugs, which has produced the cholesterol drug Lyrica and the erectile dysfunction Viagra.
This is GSK's second major deal in a few weeks. It recently sold most of its Indian nutrition business, a portfolio that includes the popular health drink brands Horlicks and Boost, to nearly $ 4 billion worth of Unilever (UL).