Amortentia, supposedly the strongest love potion in the world, cannot create real love, only a sort of powerful obsession or infatuation. True love is a magic beyond spellbooks and ingredients, something that can change the course of the world. Love cannot be bottled or canned - in order for the magic to work; for the sparks to fly, the love must be real in nature and true on both sides. Love is not only the most powerful form of magic, but the greatest form of power.
Magic in Harry Potter - Wikipedia