Information on GNC in Monson, MA 01057 Outlet Note Regular Brands GNC Massachusetts Monson 328451 Rating 4.7 based on 97 votes Address 117 Main st. Monson, MA 01057 Phone Hours may vary in different stores. For accurate hours, please contact each store directly. Suite643 Hours may vary in different stores. For accurate hours, please contact each store directly. Nearby GNC Outlet GNC Outlet - East Longmeadow GNC Outlet - Chicopee GNC Outlet - Auburn GNC Outlet - Clinton People Also Viewed