Indeed for centuries the concept of love has just been an understanding or an explanation to describe internal feelings. However, in the last few years, the definition has now been associated with neurochemistry.
Three hormones, and especially their inter-relationships, have now been established as the chemistry responsible for love, desire, intimacy and bonding. The three primary hormones are Oxytocin (the chemistry that enhances bonding in relationships, sets up appropriate psychological boundaries, and maintains intimate relationships. In the literature it is actually referred to as the “Love hormone.”), Dopamine (a powerful “feel-good” chemical in the brain’s reward system, associated with pleasure — and addiction) and Serotonin (a brain chemical associated with well-being and calmness.)