I’ve been taking naproxen for many months now; this is for backpain and EDS joint pain. I tend to take no more than 500 mg per day as like you, I am concerned about side-effects. That said, I have experienced no side-effects at all. I would suggest taking it, but if your pain improves, start to take slightly less and see how you go. Sometimes there is no need to stay on drugs for a very long time. Also they can start to be less affective if you take them long term. I have some 250 mg tablets which gives me the option of taking a smaller dose.