My good friend got exactly what you describe, a muscle soreness, and I think for him it went away when he had been on his dose a while.. I also experienced like... I want to say it was like my muscles would get stuck tense. For example I'd be on the phone for a while and when I'd lower my arm, my bicep would KILL. It would be after I held the muscle contracted for a while. It happened when I upped my dose and it went away once I established the dose.