Shares of Novo Nordisk rose more than 5% after early data showed a strong initial U.S. launch for its new GLP-1 weight-loss pill, Wegovy.

Analysts described the early prescription numbers as a “solid start,” with estimates ranging from about 3,100 to more than 4,000 prescriptions filled in the first full week.

The early momentum boosts Novo Nordisk’s efforts to regain market share from rival Eli Lilly in the fast-growing obesity drug market.

Analysts cautioned that it is too soon to judge long-term demand, especially as some data may exclude direct-to-consumer and telehealth channels, CNBC has reported.

Competition could intensify later this year when Eli Lilly launches its own oral obesity drug, which may be more convenient due to fewer dosing restrictions.