No. Cranberry supplements are not effective in treating UTI infections. These require antibiotics to effectively treat. However, cranberry supplements have been shown to be helpful for people with recurrent UTIs, as they may make the attachment of bacteria to the urinary tract more difficult. Thus if the bacteria have already established themselves as in an infection, cranberries would not be effective.No. Cranberry supplements are not effective in treating UTI infections. These require antibiotics to effectively treat. However, cranberry supplements have been shown to be helpful for people with recurrent UTIs, as they may make the attachment of bacteria to the urinary tract more difficult. Thus if the bacteria have already established themselves as in an infection, cranberries would not be effective.