900 did not do much for me. I am taking 600 mg 3 times a day. That is definitely helping, though not as much in my spine. It did help a lot with the deep pain in my feet and the burning on my calves. My hands have less tingling and burning too. I read reports from the NIH that said most people with neuropathy are often under medicated. 1800 sounded like a lot to me until I read that dose is more effective for many with peripheral neuropathy. Some people need even more.