The complexity of the concept of love cannot be overstated. In the English language the complex emotions and attributes associated with love makes a concrete definition impossible. The truth is, there is no concrete definition of love because the English language word is an amalgam of concepts which would be better represented by several words. A good example is the various related words in Greek that together broadly represent the English language concept of love. Love for persons, places or things.
With this in mind I would suggest a simple definition put forward by Irwin Federman, ” People love others not for who they are, but for how they make them feel”. So, love is how you make me feel. If I feel good to be around you and if you feel good knowing that I am in your life, that is love. This love expects all sides to put in some effort and all sides to get rewarded.
We are a biochemical species and every action of our bodies can be traced to a biochemical impulse. So, if our “feelings” are a biochemical construct, love is a chemical response that cannot easily be turned on and off. It is a chemical response to the behaviour of the people around us. If you make me feel good then I am going to love you. What happens if you stop doing the things that makes me feel good? Will those chemical pathways become weaker with time?
If you accept the biochemical nature and basis of love then the extrapolation is that love can be created in the lab. Love potions may not be science fiction after all.
How much would you be willing to pay for that potion? Would it be ethical to produce and sell such a product?