What Happens To Your Body When You Have Your First Kiss With Someone New?

Whether it's your first kiss or your 10,000th kiss, there's a mix of mystery and anticipation in kissing someone new. You wonder if this kiss will be better than you expected. You also don't know if your partner is a good kisser. So many thoughts and emotions can flood your head as the two of you touch lips for the first time. (Read why kissing is better for your health than you realized.)

Your lips have many nerves that send messages to your brain. You feel a rush of the feel-good neurotransmitter dopamine, which can make you feel a little high. Dopamine also taps into your brain's reward centers, increasing your desire for more and more of this reward. That's why your mind can quickly become addicted to thoughts about this person.

That dopamine also triggers your body to release the relaxing hormone oxytocin. Oxytocin can produce feelings of trust and bonding with this person. Kissing also reduces the stress hormone cortisol, which is why that kiss can also relax you. The epinephrine and norepinephrine cause your blood vessels to expand, and your heart rate might pick up as your body releases more adrenaline. The intensity of your experience during your first kiss with someone new can affect the future of the relationship.

What do you expect from a first kiss? Whether or not you experience that strong chemistry during your first kiss with someone can influence your feelings towards the relationship, according to a 2023 study in Frontiers in Psychology. People who believed that you must feel magic during your first kiss tended to feel that they were more in love in their current relationship. People who had a more anxious attachment style were more likely to endorse an idealized belief about their first kiss, and these ideal beliefs were linked to their romantic feelings in the relationship.

(Here are some things about kissing you probably never wanted to know.)

Not all kisses meet up to our expectations. Smelling your partner's keto breath or tasting their last cigarette can be a real turn-off. Even a slobbery kiss or dry kiss could have you asking yourself if you want to be with this person. According to a 2007 study in Evolutionary Psychology, women were more likely to use that kiss as a way to evaluate their potential mates. Researchers from this study reported in the article's discussion the results of a survey about the importance of the kiss in a relationship. When that first kiss didn't go well, 59% of men and 66% of women said they were no longer interested in the person.

While the first kiss with someone new might send fireworks through your whole body, it could seem disappointing when that magic seems to fade. Your body goes through a lot of neurological and endocrinological changes when you're in a relationship. The beginning of a relationship is usually marked by activations in your brain linked with excitement and reward. A 2016 study in CNS Spectrums compared dopamine transporter (DAT) levels in people in the early stages of a romantic relationship to those in long-term relationships. DAT is a protein that helps regulate dopamine levels in the brain. The study found that individuals in new relationships had lower levels of DAT, which could help explain the intense feelings people experience at the beginning of a romantic relationship.

As the relationship progresses, areas of the brain associated with bonding and attachment become more active, promoting family connection. According to a 2012 article in Psychoneuroendocrinology, the release of oxytocin plays a role in forming an attachment with your partner to help you form a bond (and being in love can be good for your heart). Levels of oxytocin are much higher at the beginning of a relationship and can last for up to nine months in a successful relationship. Couples whose oxytocin levels were higher at the start of the study were more likely to stay together, whereas couples with lower oxytocin levels were more likely to break up after six months.