Ayerst Research Laboratories

Ayerst Research Laboratories, later known as Ayerst Laboratories, was a major pharmaceutical firm founded in 1924 in Montreal, Canada. The company is globally recognized for developing Premarin, the first oral conjugated estrogen therapy, which revolutionized hormone replacement therapy for menopausal symptoms. Ayerst also played a key role in introducing important cardiovascular and anti-infective medications to the North American market. After merging with Wyeth (then American Home Products) in 1987 to form Wyeth-Ayerst, the entity was eventually absorbed into Pfizer following its 2009 acquisition of Wyeth. The company's legacy remains significant in the fields of women's health and endocrinology.