That special someone, the person you can’t stop thinking about, comes into the room. Your heart races. Your palms grow sweaty. You can feel yourself blushing though you haven’t said a word. These reactions to love are all in your head — literally; they are all because of changes in your brain.
There are several neurotransmitters or chemicals involved in romantic love, which could be considered courtship or pursuing a partner,” says Dr. David Spiegel, a psychiatrist and professor in the Eastern Virginia Medical School’s Department of Psychiatry and Behavioral Sciences.
Spiegel says these neurotransmitters and their interactions with different structures in the brain can change your thoughts, mood and behaviors as a relationship progresses. The biggest biochemical players in feelings of love are dopamine, oxytocin and vasopressin.
Dopamine, a chemical associated with feelings of pleasure and euphoria, plays a huge role in the beginning of a relationship. Dopamine is part of the reward system of the brain, a complicated system that includes structures such as the nucleus accumbens and cadaute nucleus. These structures of the brain are not just used for falling in love, but are involved in the enjoyment of food and sex, too.
Your brain always wants more dopamine, encouraging you to seek out sex and relationships. As love progresses, dopamine interacts with other neurotransmitters that leave you wanting more and more time with just that special someone. It helps you feel excited and euphoric around your new partner. Unfortunately, too much dopamine can make you ignore important information from another important set of structures in the brain: the social interaction network.
This network, including the medial prefrontal cortex, helps you fall in love and understand social interactions. It helps you identify emotions and feelings of other people, letting you know if the other person is as interested in you as you are in them.
However, when you have too much dopamine, you miss out on this important information. That can lead to obsessive behavior and jealousy — the negative sides of love.
Oxytocin and Vasopressin
Oxytocin, called the love or cuddle hormone, helps couples build feelings of attachment as the relationship progresses. Stored in the brain, the hormone is known for being released at orgasm and at the moment of childbirth — it’s also partly responsible for the bond between a mother and baby.
“Beyond the initial head-over-heels and emotional part of love, there is also partner attachment and pair bonding,” says Spiegel.
When head-over-heels love is gone, you have decreased dopamine, but more oxytocin and vasopressin are involved.”
As you move further into a committed relationship, oxytocin helps you feel calm and secure. These positive effects even help you feel calmer when you are not in the same place as your partner. Oxytocin changes how your body responds to stress. Just thinking of your partner may help you lower your heart rate, reduce sweating and help you make more rational decisions.
Oxytocin helps support long-term love by changing how you react to your partner, too. Parts of the brain including the insula (which helps you be self-aware) and the anterior cingulate cortex (which controls motivated behaviors) react differently to the person you love than to other people.
“One reason why a relationship works is because if you are in a conflict with someone you love, you adjust your cognitive strategies to resolve conflicts,” says Spiegel. “You are going to solve problems differently with someone you love to maintain the relationship.”
Vasopressin serves a similar role as oxytocin. It helps build bonds and contribute to longer-term, monogamous love. It helps you develop a preference for your partner, instead of encouraging you to seek out many partners.
Without these three hormones, romantic relationships in humans are not possible. You need dopamine to enjoy being with your partner, vasopressin to motivate you to seek out your specific partner and oxytocin to maintain your relationship long-term.
There are a few other hormones at work, too. The sweaty palms and racing heart when you first fall in love come courtesy of adrenaline. And when you’re in love, testosterone — the sex hormone in both men and women that gives us libido and sex drive — is elevated.
If your Valentine were to say, “You raise my levels of oxytocin and vasopressin, baby,” it wouldn’t sound very romantic. But your partner has the power to change your brain — the very thing that makes you, you. Without the person you love and their effects on your brain, you wouldn’t be the person you are today.
What’s more romantic than that?