i’ve taken 15 w/ a protein shake as a quick meal replacement without any problems. some people are bothered by large quantities of it, everyone’s different. I definitely wouldn’t worry about breaking it up into more servings unless it was specifically causing you some GI stress.
I wouldn’t take any supplements that are not from this website, a special internet website, or whole foods (or a respectable health food store). I have a friend who had a terrible reaction to a grocery store brand. The supplement industry is not regulated, and many companies put all sorts of contaminants that can actually harm you in their products. It’s better not to take anything or pay a little extra.