Means: having an effect on a living organism. bioactive molecules.
It is used sometimes with the adjective "more".
"More Bioactive" or "The Bioactive" is a marketing tool and has no scientific meaning as there is no scale of bioactive.
It is sometimes used to mean the 'product' also exists in the body 'naturally' and that is touted as a 'good' thing without data supporting that occurrence.
It is not dissimilar to full spectrum lighting. Both a candle and the sun are full spectrum as the term is not defined.
Edit: or am I incorrect?