4 units china gh is about 2-3 units american gh, he should be ok. little water in hands, sausage fingers for a while, but nothing major, just will look bigger which is good, it subside.
he is low bf and 190 which is already quite big with numerous cycles, his body will handle it with no problem.

only side effect i can see for him is vivid dreams and good deep sleep, on gh you sleep so well and so deep yet many times you can remember your dreams well which can be a good thing or a bad thing.. LOL