No, I got excellent results in only one use. What type of dog are you using it on? Maybe coat type makes a difference.I tried it before I got very many replies and wasn't impressed. I mixed it pretty dark, didn't measure. He didn't turn blue but he doesn't look whiter either. I'm definately going to order some whitening shampoo but I may try this again before the stuff I order gets here. Maybe it gives better results over time?