Eli Lilly Thursday raised its annual profit forecast and sales of its popular weight-loss drug Zepbound crossed $1 billion for the first time in a quarter.

The drugmaker now expects adjusted profit of $16.10 to $16.60 per share for 2024, compared with its prior forecast of $13.50 to $14.

Lilly and Danish rival Novo Nordisk are racing to increase manufacturing capacity to meet unprecedented demand for their popular weight-loss drugs that have been shown to help patients lose as much as 20% of their weight on average.

Analysts have said the companies will likely split the U.S. market roughly 50-50 by the end of 2024, as Lilly increases its manufacturing capacity and closes the gap with Novo.

Lilly has said it expected manufacturing in its new production lines to start over 2024 and for a new plant in Concord, North Carolina, to begin operations towards the end of the year.

Investor interest in these therapies has propelled Lilly's market value to over $700 billion in recent months. The stock has risen about 32% so far this year and was up 9% in premarket trading. Some analysts expect the market for weight- loss treatments to hit $150 billion by the early 2030s.

Quarterly sales of Mounjaro came in at $3.09 billion, while Zepbound sales were $1.24 billion.

Analysts had on average predicted sales of $2.49 billion for Mounjaro and $930.8 million for Zepbound for the quarter. They expect the drugs to make a combined $15 billion this year.