Eli Lilly will spend more than $5 billion to expand an Indiana manufacturing site and eventually make more doses of its popular weight-loss and diabetes treatments, Zepbound and Mounjaro.

The drugmaker said Friday that it was more than doubling its investment in a site near its Indianapolis headquarters. But it will take time for the location to start producing.

The company broke ground for its Lebanon, Indiana, manufacturing plant last year and expects to start making products there near the end of 2026. Production will then increase through 2028.

Lilly said it would add $5.3 billion to the $3.7 billion it had already slated for the site. Company officials said in a statement that this amounts to the largest manufacturing investment in the company's history, which dates back to the 19th century.

The site will make tirzepatide, the main ingredient behind both Mounjaro and Zepbound.

Zepbound, the weight-loss treatment, received U.S. regulatory approval last fall. The two drugs combined to generate more than $2 billion sales in this year's first quarter.

But Lilly has struggled to make enough supply to keep up with the growing demand, as has its rival, the Danish drugmaker Novo Nordisk, which makes the popular weight-loss drug Wegovy.

Company officials have said they expected some manufacturing increases to occur starting in the back half of this year.

Analysts expect Zepbound and Mounjaro to eventually generate well over $30 billion in combined annual sales for Lilly, according to the data firm FactSet.

Shares of Eli Lilly and Co. rose slightly to $809.70 Friday morning, in line with the S&P 500 index.