Shares in Novo Nordisk fell as much as 6% on Friday to their lowest since August 2021, extending recent losses to wipe out almost all the gains made since the drugmaker launched its blockbuster weight-loss treatment Wegovy.

(Reuters) -Shares in Wegovy maker Novo Nordisk fell around 4% on Friday to their lowest since August 2021, after U.S. President Donald Trump sent letters to major pharmaceutical firms to cut drug prices in the United States.

Compounding pharmacies are crimping sales of Novo Nordisk's obesity drug Wegovy by making what are essentially copies of the name-brand medicine. The company says it trying to stop them.