Most reviews complain that this does nnot work, I have sucessfully used this on 3 dogs all with white faces and severe tear staining ranging from light brown to dark red brown running all the way down their face. Since it does not have harmful chemicals like the bleaching tear stain products most companies sell (which actually stained one of my dogs fur yellow!) Nor is it illegal like angel eyes. It states that you may have to use it for some time before you see results and this is true but well worth the while. I used it twice (even 3 times a day) for 3 months before I noticed the tears had almost completely disappeared, by month 4 they had lovely bright white faces! You only need a little (2 drops) on a cotton pad and gently rub in the stain, then you MUST dry it as most staining gets worse if the area stays wet as most tears have a bacteria in it that causes the red/brown colouring. It is also important to dab any tears dry as often as you can so you keep their faces dry most of the time. This stuff is very gentle that is why it takes longer to remove stains, but it DOES work. Another thing is you cannot stop using any tear product completely as the stains will come back, I now use it once every other day and it has kept it away.... in fact I am back for more today.