It started turning gray after at around 24 drops. I added up to 35 and it only got darker...almost black. So I redid the test and got the same results. I added so much solution trying to get the desired brown that I used up the whole bottle of solution. I've not done any other tests. I've had testing done at the doctor for thyroid and were told the results were normal. But I know something isn't right. I'm always tired, constipated, my hair is falling out in clumps, I cannot lose weight and I feel too bad to exercise. After doing some research on my own I purchased the adrenal fatigue urine test (Osumex Adrenal Function Urine Test). Now I'm even more confused.