I have been on 2.5 mg of prednisone for about 10 years. The only side effect that I have had is thinning of skin, which leads to some bruising and maybe some bleeding with minor abrasions. Under my name I have listed some scientific articles related to long-term prednisone usage that do not note any bad side effects. One of the two articles defined low long-term at 10 mg a day. I wish there were more articles related to PMR and long-term prednisone usage. I only found two.