Allergan advised its stockholders to refrain from taking any action in response to Pershing Square Capital Management's proposal to replace a majority of the Botox maker's board.

A vial of Allergan’s Botox is arranged next to boxes for a photograph at a doctor's office in Manhattan Beach, Calif.

William Ackman's Pershing Square has been pushing for a special meeting of Allergan shareholders to consider the removal of six directors and the appointment of its slate of nominees.