Seriously, my primary function is that of a synthetic organic chemist who figures out how to economically manufacture compounds in the lab, and then upscales that to commercial production.
So if you truly want to do EXACTLY what i do, you should major in chemistry and specialize in organic synthesis.
If you want to be like other supplement company guys that simply find supplement ideas and then find chinese sources to manufacture the stuff for them, then you can probably just major in any of the biological sciences.
YOu are going to have more fun and make more money doing it my way however