The “drug” is called love and the “overdose” is often referred to as “the early stages of love.” The brain chemicals called neurotransmitters have everything to do with the very physical sensations that we all feel when falling in love. It is a stimulant, much like an amphetamine, that causes the release of norepinephrine and dopamine. The major brain chemicals for these feelings are dopamine, opioids, adrenaline, and serotonin. Phenylethylamine or PEA: This is a chemical that naturally occurs in the brain and is also found in some foods, such as chocolate. Love starts with chemicals jumping between neurons in your brain -- so why do we think it's in our hearts? Love is a cocktail of brain chemicals. It's responsible for the head-over-heels, elated part of love. Love is a powerful motivator because it stimulates all your happy chemicals at once.

When we are falling in love, chemicals associated with the reward circuit flood our brain, producing a variety of physical and emotional responses—racing hearts, sweaty palms, flushed cheeks, feelings of passion and anxiety. Long-term attachment and lasting bonds of affection develop over time. These bonds are cemented not only by shared experiences and mutual displays of dependability, but also by the brain chemicals vasopressin and oxytocin. This chemical is released when you are falling in love.