I've been using Ostarine since it first came out. I am also on low dose TRT so I use it to safety increase my T levels. I normally dose at 25mg/day for 8-10 weeks and then take a four week break. I have been using it this way for several years without any issues. I have blood tests every 8 weeks and everything is fine. For me it takes about 4-6 weeks before I really notice any physical changes. Strength will increase after a couple of weeks. I find its best for recomp. I haven't really gained a lot of mass from Ostarine, but then that's not my primary goal.