I have read about orally injested glutathione seeming to not be effective. I tried some of the NOW brand glutathione and can definitely say I am feeling something when taking it. It is a 250mg dose, so I will probably lower it as my heart speeds up when taking it. The benefit is that my neck which is always stiff and can be cracked many times a day, is now moving about 60% more freely. It still has that sound of something rubbing against each other...not sure if it is from the muscles or the discs.
I think people just have to try it to see if it does anything for them.