What shipping carriers do you use? December 07, 2022 23:05 Updated For your initial order we use UPS, but for the monthly cartridge shipments we are using USPS. Related articles When will I receive my Sutro? Where does Sutro ship to? Is the product going to be available at any retailer? Does Sutro have a beta testing (or dogfood) program? Does Sutro have a seasonal cartridge program?