I just finished reading an article by Dr Mercola who interviewed a Methylene Blue (MB) researcher. The researcher said there used to be pills of 60 mg MB that were used for UTIs. He put his mother on a dose of 1mg per kg body weight a day. He generally recommends 0.5mg/kg up to 1mg/kg (pharmaceutical grade as any others have heavy metal contamination) taken with 1000 mg of Vit C in the ascorbic acid form as it reduces the MB to be bioactive.
I just started taking 3drops in about 6oz of water per day, working up to a dose that I can feel better with. My rough calculation is that with 10mg/ml of MB, my weight of 118 in pounds becomes 53.5kg, divided by 2 for the .5mg/kg (or you can multiply by .5, your choice, same answer) becomes a good dose of 26.75mg MB which is then 2.675ml, which then is slightly over 1/2 teaspoon (conversion charts are amazing). It will take a lot of drops to get to that dose! But if a lower dose works, I'm happy.
Chronic Bladder Infections
I am an intermittent catheter user, therefore, I have chronic bladder infections. Ever since I began using Methylene Blue I have stopped getting UTIs. I use Methylene Blue 1% solution. The normal dose is 10 drops in water morning and night. I only need 2 drops morning and night. I use a straw to drink it so my teeth won't turn blue. It has the added benefit of stopping my candida symptoms.
Having said this, I am also very careful about what I eat: no sugar or fruit of any kind. I don't use any artificial sweeteners. I avoid wheat and other grains. I eat canned beans, eggs, fish, chicken, vegetables, and brown rice. I have to avoid nuts.