UK (excl NI) residents, 18+. To participate, purchase one of the Listerine® Total Care range (excl. all 95ml & 250ml pack sizes and Listerine® Total Care Sensitive) between 23.03.21 & 15.06.21 (valid receipt must be retained to claim prize), then complete entry form on www.listerine.co.uk/21daychallenge/enter by 23:59 on 15.06.21. Only 1 entry per household. Internet access required. Prizes: 1 x £5,000; and 5x £1,000 to be paid by bank transfer only (valid bank details must be provided to claim prize).