Ostarine is currently in phase II clinical trials conducted by its developer, Gtx Inc., for treating breast cancer and osteoporosis. “The fact that Ostarine is only in phase II trial means that there is no evidence that Ostarine is safe for humans to consume,” Serrano writes in his affidavit. “Ostarine has many recognized potential side effects, including hepatoxicity (liver damage), and markedly lower plasma HDL cholesterol (raising the risk of heart disease). Ostarine also has less serious side effects including headaches, back pain, and diarrhea.”
In February 2017, American triathlete Beth Gerdes was given a 2-year suspension for presence of ostarine, and American triathlete Lauren Barnett was given a 6-month suspension for the presence of Ostarine. Both triathletes claimed contamination from salt tablet supplements. Lauren Barnett was able to provide tablets and sealed bottle tablets which both tested positive for contamination, thus only the 6-month suspension. The 2-year suspension still stands for Beth Gerdes who provided tablets for testing, but tests showed only low levels of ostarine not high enough to confirm the finding. 
For the muscle gain or bulking, the suggested dosage is 25 mg. You will have to take 25 mg on a daily basis for four to six weeks. You will notice the difference in the first week itself. For the best result, you need to be more careful to follow the time period and dosages. If you want, you can also take a high dose like 36mg. You can also continue it for eight weeks. But you will be allowed for this dose and time period if you weigh 210lbs. PCT is not necessary for the normal dose. But if you are taking the high dose, PCT is the must.