CVS and Walgreens are among the national pharmacies holding sign-up events.
GNC, Target, Wal-mart and Walgreens have been accused of selling tainted products.
The drug store chain said a significant factor was scrutiny of corporate tax “inversions.”
Companies and trade groups say people are setting up appointments this week.
The products were pulled from stores after charges they were tainted and mislabeled.
The Senate's hearing on the epidemic is turning into a major event.
Senate Majority Leader Harry Reid (D-Nev.) said if Walgreens decided to move its headquarters to...