BinaxNOW COVID-19 Antigen self tests are available at the counter of Magnolia Pharmacy. Demand for quick COVID-19 testing appeared to outpace supply in Houston last week as the delta variant spread rapidly. Testing slots at CVS and Walgreens were booked up several days out and you’d be lucky to find a store with any home testing kits left. Over-the-counter COVID-19 test kits are now the top-selling items. Manufacturers of BinaxNOW Self Tests said demand for its products is increasing as cases rise.