How do you know if we are making progress? A good question! A possible answer is the Neurotoxic Metabolites Test. This is a simple urine test you can do at home to measure H2S. I'm not sure if this test is reliable, but a couple of things makes me think it is. I did this test before, during and after Antibiotics last year. I was strongly positive before and after Antibiotics , but negative while taking them. This indicates that the ABx did inhibit the H2S causing bacteria, but they grew back as soon as I stopped ABx. The other reason I have some faith in this test is that I gave it to my girlfriend who has no symptoms, and she tested negative.