Eli Lilly and Company (Lilly) has announced an additional $5.3bn investment in its manufacturing site in Lebanon, Indiana, increasing its initial investment of $3.7bn to $9bn.

The new investment will boost the company’s manufacturing of active pharmaceutical ingredients (API) for its weight-loss drug Zepbound and diabetes drug Mounjaro.

Zepbound and Mounjaro, both known as tirzepatide, are in shortage in the US and expected to have limited availability across most doses through the second quarter of this year.

The enhanced production will allow more adults with chronic diseases such as obesity and type 2 diabetes may benefit from these important treatments, said the US drugmaker.

Lilly started construction on the Lebanon site last year and expects the facility to start manufacturing medicines toward the end of 2026, with operations scaling up through 2028.

Lilly chair and CEO David Ricks said: “Today’s announcement tops the largest manufacturing investment in our company’s history and, we believe, represents the single largest investment in synthetic medicine API manufacturing in US history.

“This multi-site campus will make our latest medicines, including Zepbound and Mounjaro, support pipeline growth and leverage the latest technology and automation for maximum efficiency, safety, and quality control.

“Importantly, we are investing in our home state of Indiana, creating high-wage, advanced manufacturing, engineering, and science jobs for hundreds of current and future Hoosier families.”

As part of its additional investment in the Lebanon site, located within Indiana’s LEAP Research and Innovation District, Lilly intends to add 200 highly skilled full-time jobs.

The company will recruit engineers, scientists, operating personnel, and lab technicians, creating a workforce of 900 full-time employees, when the facility is fully operational.

In addition, the expansion of its Indiana manufacturing facility will create more than 5,000 construction jobs during its development, said the US drugmaker.

Lilly manufacturing operations executive vice president and president Edgardo Hernandez said: “Lilly’s commitment to meeting the demand for our life-changing medicines goes beyond buildings and extends to improving education opportunities and upskilling a global workforce of the future.

“Academia is a critical partner to both industry and government as we work together to advance innovation in our state and communities around the globe.”

The Indiana state is partnering with Lilly to support its expansion project through infrastructure solutions, road improvements, water, electric and other utilities.

The state will also enable workforce development and certain economic incentives linked to the company’s achievement of investment and employment goals.

The support includes the contribution of land, pending approval, for the construction of a learning and training centre and help raise capital for the completion of the expansion project.

Indiana Governor Eric Holcomb said: “Lilly continues to play a transformational role in shaping Indiana’s opportunity economy, and I couldn’t be more proud about their pole position leadership in developing the LEAP Research and Innovation District in Lebanon, Indiana.

“Lilly had a world of options to consider before making this investment, and choosing Indiana once again reinforces the incredible environment we’ve cultivated and the talented workforce we have to carry Lilly’s success forward.

“I can’t wait to see the incredible benefits this investment leads to for patients around the world, knowing they were made in Indiana.”