What difference does it make taking HGH versus MK-677? I primarily take HGH and T4 for shoulder, knee, and ankle healing and helping with very gradual strength gains. I was pinning 2 IUs twice a day, but I have 2 little, NOSY kids. I switched to taking 25 mg MK-677 at night, and feel like I get the same. The big plus is that it is much easier to keep kids out of my business.