Novo Nordisk has raised its annual sales guidance several times a year since launching its popular diet pill Wegovy in 2021. However, recent weakness in U.S. prescription data has some investors and analysts wondering if the strong run that helped Novo Nordisk become Europe's most valuable listed company (at its peak of $615 billion) is coming to an end.

In February, the Danish drugmaker forecast sales growth of 16%-24% in 2025 at constant exchange rates, much slower than in previous years.

Even that goal may no longer be realistic, and the company may lower its guidance when it releases first-quarter results on May 7, six analysts and investors said. Novo Nordisk said in February that it had increased its supply of Wegovy in the United States to meet surging demand and said its guidance reflected the adjustment.

However, IQVIA data cited by analysts showed that weekly prescriptions for Wegovy in the United States have leveled off since mid-February. At the same time, competition has intensified from Eli Lilly's weight loss injection Zepbound, which outsold Wegovy by 128,000 prescriptions in the week ending April 11. Novo Nordisk and its competitors also face the risk of their products being dragged into the trade war launched by U.S. President Trump.

Although the consensus forecast of 25 analysts from the London Stock Exchange Group (LSEG) shows that Novo Nordisk's sales are expected to grow 19% in 2025, Bank of America analysts expect the company to lower its guidance to 14%-22%, which would be the weakest growth rate since 2021. "I'm highly cautious about Novo Nordisk and the possibility of a guidance cut is real," said Lukas Leu, a portfolio manager at Bellevue Asset Management, which owns Novo Nordisk shares.

Novo Nordisk has lost $230 billion, or 45%, of its market value since early December as investors worried about its ability to compete with Eli Lilly in the hotly competitive weight-loss drug market and its next-generation drug CagriSema's clinical trial data fell short of expectations.

Some analysts expect prescriptions for Wegovy and diabetes drug Ozempic to rebound if the U.S. Food and Drug Administration (FDA) strictly enforces its ban on generic drugs. Novo Nordisk said the ban could shift demand to its original products.