I'm using resveratrol for about three years now (1 per day (evening), 40mg trans-resveratrol). I have taken it together with Copaxone, various Antibiotics and LDN and Tysabri. My blood work has never shown any problems (including the liver).
I cant say much about the effect of resveratrol because I only used it with other supplements and drugs. But there is certainly no direct difference when I stop it for a month and restart taking it afterwards...
Treatment: Gilenya since 01/2011, CCSVI both IJV ballooned 09/2010, Tysabri stopped after 24 Infusions and positive JCV antibody test, after LDN, ABX Wheldon Regime for 1 year.