Just my personal experience with MK I hope it helps easing into it. At 5 (actually 6.25mg) i split my 12.5mg capsules I still felt stimulated but mildly so. I felt my legs were tingly the first few days of use and increased appetite. Sleep was doable at this dose. Yes it was restless a couple nights.. I'd dose first thing in the morning. After a few days I didn't feel stimulated at all anymore but gave it 2 weeks before upping the dose. Increasing the dose to 12.5mg I got the same sides as at 6.25mg but equally mild and my body adapts quickly. Additionally I'd get numb hands at times. Surprisingly after increasing to 25mg I'm not noticing much apart from my hands still falling asleep on occasion. As for muscle fullness. Tough to answer but zero weight gain/bloat at any dose for me BUT I'm cutting at the moment so my diet isn't exactly conducive to muscle fullness. Pumps in the gym have been great though, painfully good despite a caloric deficit.