I've run Osta twice in the past, and if you're interested, here's the brief results of those:
My first cycle: Osta Rx at 25mg ED (dosed in three pills spread throughout the day). Gained 4-5 solid pounds, no increase in bf%. Great mood, energy, endurance, and pumps in the gym (compared to natural, may not be impressive for someone who has ran gear in the past). Also, impressive improvement in appetite and strength. At the end of the second week, I reaggrivated an old injury performing an olympic movement without proper warmup. Interfered with my gains slightly, but healed much faster than expected (there are claims that the slight elevation in estradiol levels in some Osta users influence quicker recovery from injury). Third week and half of fourth were amazing. However, at the end of the fourth week, my energy, libido, and mood began to deteriorate. "PCT" was Super Test by BEAST nutrition. My strength stayed at an all-time high and I did not lose any of my weight. Loss of energy and libido stayed, so the Super Test did absolutely nothing.
Second Cycle: About 7 months after my first cycle, I ordered Osta from a different source. This was in liquid form. The chemical spilled during the shipping process, leaving me with much less than I'd ordered. Took 25mg orally an hour before training ED. Also took .2mg of Liquidex EOD, starting the second week (should have started it with the Osta on the first day because dex takes some time to build up in your system). Right when the Osta's effectiveness would have started to reach its highest, I ran out (two days into the 3rd week). This cycle was also different because I was working much more, not eating as much, and had been very stressed. Had nearly the same increase in strength, endurance, pumps, etc. in the gym. Libido (which had still been fucked up from the first cycle, unrelated stress, and lack of sleep) took a 180. Appetite improved, which was great because a few stressful weeks prior had absolutely destroyed my appetite. Started to see acne on shoulders, arms. Continued to run Liquidex at .1-.2mg EOD for two additional weeks after running out of Osta. Even with the liquidex, my libido and energy started to slowly deteriorate again. About one month after my last dose of dex, I noticed I was getting gyno in my right nip.
Now: I ordered Liquid Tamox (nolva) and from last Sunday to next Sunday I'll be using 20mg ED. In just two days, I feel a difference and my nips are showing slight signs of improvement already. I think this minor novla restart is well-needed. After this week, I'll determine when I'm going to start my third cycle of Osta based on my schedule, how I feel, etc.