In 1879 Robert McNeil opened his first retail drug outlet in Philadelphia, Pennsylvania. Growing rapidly as a producer of prescription pharmaceuticals, the company was incorporated in the U.S. in 1933 under the name McNeil Laboratories, Inc.

McNeil Laboratories first introduced the flagship product TYLENOL* acetaminophen as a pediatric elixir in 1955. McNeil products have been available in Canada for more than half a century, initially through distributors then with the creation of McNeil Laboratories Canada.

McNeil became a member of the J&J Family of Companies in 1959.

In 1980, the J&J Baby Products Company in Guelph’s facility became responsible for the marketing and distribution of the over-the-counter TYLENOL* brand.

In 1984, McNeil Consumer Healthcare, division of Johnson & Johnson Inc. began marketing the TYLENOL* brand.

An additional 17,000 square feet are used for Quality Assurance, Process Development and Research & Development laboratories.

55,000 square feet are devoted to additional office space and employee-related facilities. In late 1988, a 35,000 square foot addition to the manufacturing and Research & Development areas was completed, and in 1998, another 14,000 square foot addition was added to the Consumer and Public Relations area and the Operations and Cafeteria area. This is the fourth phase of a long-range expansion plan and is designed to meet the significant increase in consumer demand for the market leading TYLENOL* brand.

The employee-related facilities and office space are located in an area called "The Link", which joins the original 1978 building with the expanded facility. This two-story construction with dining area opens to the full building height, with skylights mounted in the ceiling.