This the Exact brand you can find at Zehrs. It is equivalent to Reactine but much cheaper. I tried both and found them to be the same, including the ingredients. Why pay more when the no name brand works just as well! It promises to work in 20 minutes, It seem to kick in. My eyes were swollen and so itchy. Within 20 - 30 mins they felt much better. I do not believe they last 24 hours. I found it wore off after 12 hours.