I purchased cardarine and andarine from SarmsX. I discontinued the S4 and cardarine after 4 weeks after reading about the potential for cancer caused by cardarine. I had a cancer scare already in the past year and didn't want to tempt the fates. I wasn't seeing any appreciable results from the S4, but in fairness, I may not have used it long enough. Cardarine gave me some rapid and startling (to me) results very quickly.
I run 3-4 days a week for a set distance of 1.5 miles. That's the distance I train for, that's what my body is conditioned to. If I try to run much farther than that, I tire out quickly. About 2 miles is my upper limit.
Within a week after starting cardarine, I was able to run my distance in considerably faster times than my usual time, shaving off seconds in the double digit range, and continuously improving each week. I could also run longer distances without fatiguing. I pushed it to 2 miles after only 1 week and I felt like I could easily push it another mile. I didn't test that theory because I don't need to run long distances for what I do.
Truth be told, I hate running and have to force myself to do it each time, even though I've been running for over 2 years now. Once I get past that first 1/4 to one half mile, I settle in. But those first 2 laps on the track are always hard, resisting the constant barrage of excuses to quit. I noticed on the cardarine, after the 2nd week, I was no longer having to fight off excuses. It was much easier to run and I felt better doing it.
That was my one experience with sarms or the company SarmsX. I can't speak for the S4, but the cardarine worked really well for me. After looking up real studies, I have since learned that cardarine in 20mg/day dosages is not likely to cause any problems, so I will be ordering again soon. I may try it with LGD or ostarine next time.