The Allergan facility in the Mayo town of Westport recently shipped the 100 millionth vial of Botox.
The Westport facility is responsible for manufacturing the global supply of the anti-wrinkle, injection treatment as the company marked 30 years since the product first received approval.
Allergan confirmed the announcement as it opened a new €160m biologics facility in Mayo today.
The new facility will add 63 jobs and brings Allergan’s total investment in Ireland since it began operations in the country to more than €750m.
It will feature new manufacturing suites and microbiology and cell-based laboratory.
Wayne Swanton, Executive Vice President of Global Operations at Allergan said they were embarking on the next chapter of growth and innovation for Allergan’s botulinum toxin brand and other biologics products.
"The sensitivity of biologics in the manufacturing process is like no other. It requires a level of exactness in manufacturing and handling throughout the whole supply chain around the world, which is truly unique. That journey starts here in Westport on the west coast of Ireland."
“We continue to believe Ireland is an outstanding country for investment and expansion for all our products that are manufactured here in Westport."
Martin Shanahan, CEO of IDA Ireland said Allergan has grown its presence in Ireland from a workforce of just 25 employees in 1977 to almost 2,000 people today.
"Securing investment for regional locations across Ireland has been, and will remain, a key focus for IDA Ireland and Allergan’s success here and its continued commitment to Mayo and Ireland with this additional investment is a clear endorsement for other companies considering investing in Ireland.”