If i take only 1/2 scoop of "serious mass" weight gainer instead of 1 or 2 heaping scoops, will it be safer for my health? i'm 27yr, 120lbs..

Not enough info: Are you concerned about the amount of protein in one scoop of your weight gainer, or is this a question about caloric intake? This is also dependent on what your health goals are, ; what your current health state is. What is your current fitness level? Most importantly, your question is vague, what do you mean by safer, in regard to your health how? I would recommend speaking to your pcp or rph.