When Cupid’s arrow strikes in cartoons, those pounding hearts, red-hot cheeks, and moony eyes are no joke, says Mary Adeli Lynn, DO, codirector of the Loyola Sexual Wellness Clinic. She explains what’s happening in our brains and bodies at the moment of impact—and beyond.

By Kathleen Murray Harris
Updated March 16, 2017
John Devolle
John Devolle

Initial Attraction.

Love at first sight? More like desire. When you get an inkling that you may have an interest in someone, your brain starts to release feel-good chemicals, like dopamine, which create a strong sense of desire. Then comes a flood of adrenaline and norepinephrine—neurotransmitters that bring on flushed cheeks, sweaty palms, and a racing heart. You're in lust.


If there’s a lack of continuous contact, you’ll stay in the lust stage because there’s not enough shared experience to move into the next phase of attraction. This is what we call a crush.

Getting Close.

As you become more comfortable with the person, your hormones do, too. There’s a theory that blood flows to the pleasure center of the brain and lowers serotonin levels, giving you feelings of deep longing and intimacy. Meanwhile, your brain continues to release small doses of epinephrine (producing an adrenaline boost like an EpiPen), which gives you increased energy and exhilaration.


Once the body develops a tolerance to the pleasure stimulants, endorphins and the hormone oxytocin flood the body, creating a sense of well-being and security. You’re moving toward the lasting-partnership stage, in which you feel a deep protectiveness. This phase will last about two years. But it all depends on the health of your relationship.

Keeping the Flame Alive.

As time goes on, you can rekindle lustful chemical reactions through touch—by holding hands and kissing or even simply gazing at each other. Cuddling is important, as is novelty. Learning new things together can release dopamine and bring on happy feelings again. Plan sexy surprises or do something nice for the other person. It can spark those neurotransmitters to provide a more euphoric, lustful feeling.

Long Love.

When you’re in a happy relationship for years, there continues to be a surge of positive chemicals in your body. Research says that being in a loving, long-term relationship can boost your immune system and that couples tend to live longer than singles. (Even having a pet you love can up longevity.) A relationship that spans decades can still make your heart go pitterpatter—and your face turn 50 shades of red.