Running across your question a little late... but MK-2866 is also known as Ostarine. It is the second SARM released on the research chem market, and it is showing less sides (and probably less anabolic / fatburning effect) than S4.
In other words, MK-2866 is not GHRP or GHRH -- though combining all three would be a fantastic zero-HPTA shutdown stack. For GHRP and GHRH info, google "datbtrue" and find his most recent guides. To very briefly summarize, GHRP-2 or GHRP-6 plus CJC without DAC, 100 mcg of both as subcutaneous injections, 1 to 3x a day, is the standard protocol.