All About the Chemistry of Love

woman kisses man in nose

Do you want to know more about the chemistry of love and the relationship between affection and the brain? Then read on. When people feel intensely attracted to someone, they are flooded with chemicals like dopamine and oxytocin. They can experience rushes of adrenalin and norepinephrine and may feel like they are going a little crazy. This is one reason why so many people refer to the sensation of love as a “drug”. Many scientists agree that the feeling of love is a chemical reaction.

Why do we fall in love or feel like we are?

We are more likely to experience these intense feelings at the very start of a relationship. When you first meet someone you are attracted to, your knees might start to feel weak, your heart may beat faster and your palms could even feel sweaty. You may feel “butterflies” in your stomach and could find it difficult to think about anyone else other than the object of your affections.

Why do we fall in love with certain people?

People can feel attracted to specific people for various reasons. You might find yourself falling for someone who appears to be healthy and fertile, someone who has certain personality traits, people we believe are similar to us and so on. It’s thought that men with high testosterone tend to be drawn to women with particularly “feminine” features. Many people experience a surge in dopamine when they are starting to fall for someone. Dopamine is a hormone which controls the reward-seeking part of the brain. Dopamine surges can leave us feeling incredibly excited, even euphoric. Drugs and alcohol also affect the dopamine receptors in our brains. When you first fall in love with someone, you can actually feel addicted to them, whether your feelings are reciprocated or not.

More about the science behind love

Oxytocin is a bonding hormone. Your oxytocin levels may rise whenever you are with someone you are attracted to, or even when you are just thinking about them. Women also experience oxytocin surges when they have just given birth due to the way that they feel bonded to their offspring. A rise in oxytocin is your brain’s way of telling you that you feel close to someone and that you should stick with them. When our oxytocin levels rise, we can feel much close to someone and trust them deeply. However, it’s not all good news – in cases of unrequited love, people under the influence of oxytocin can start to feel incredibly jealous when they see someone with someone else or suspect they are cheating on them. This can lead to darker forms of behaviour such as stalking that make others feel uncomfortable.

Love and serotonin

why do we fall in love

The drop in serotonin levels that some people experience when they feel attracted to someone can make people feel a little obsessed. It can make it hard for you to stop thinking about someone and can cause the sensation of “butterflies”. People who have obsessive-compulsive disorder (OCD) also tend to have lower levels of serotonin.

Adrenaline and norepinephrine

Have you ever noticed your palms start to sweat, your mouth begin to dry and your heart rate rise during the early stages of love or infatuation? This is linked to rises in adrenaline and norepinephrine. You may experience these symptoms when you have recently met someone you like even if they have barely acknowledged your existence as well as in the first waves of a real relationship. These symptoms can be experienced even when you simply look at the person. You may find it hard to sleep when these rises occur, and you could find yourself awake for hours trying to shake the other person from your mind. People with higher levels of norepinephrine can also feel more emotionally dependent on other people.

How love works: judgement issues

Another thing that tends to happen to the brain when people are besotted with someone is that their frontal cortex shuts down. Studies have shown that the area of the brain in control of making sensible and rational decisions actually stops working efficiently, leading to people making very questionable judgements. People often start acting in reckless ways in order to remain or start a relationship with someone and they may feel angry when their friends and family are dubious about their romantic aims. The mid-temporal cortex and amygdala can also close down in the early stages of love or infatuation. The job of the amygdala is to control fear, whilst the mid-temporal is tasked with managing negative emotions. Once these shut down, we may stop seeing the risks associated with pursuing a relationship with someone. This means we have a vastly reduced fear of negative consequences and are more likely to do things we come to regret later.

Why do we fall in love if it sounds so unpleasant?

Although much of the above may also sound unpleasant when written down in front of us, many people actually enjoy the sensation of being in love or even simply infatuated with someone. Love and infatuation can often feel pleasant and deeply unpleasant at the same time. However, these feelings don’t tend to last, and even the crushes we might have on someone can tend to pass after a couple of weeks or so. Once the initial rush passes, things tend to become less dramatic, and we can start to feel more rational. Your serotonin levels will begin to normalise, and you won’t experience as many hormone surges as you did before. You may start to feel more tranquil, less obsessive and able to think about things other than the object of your affection.

Long-term love and chemistry

There is also a lot of fascinating information to digest on the relationship between brain chemistry and long-term love. If you do enter into a long-term relationship with someone that lasts for months, years or even decades, your brain will be affected by chemicals including the pituitary hormone vasopressin. This hormone is associated with feelings like security and calmness. It can also help us remain faithful to and protective over our partners. Oxytocin also has a big role to play and helps us maintain the bond we feel with someone special. This chemical helps attachments remain strong and can play a big role in helping parents feel close to their children too.

Research into the science behind love

chemistry behind love serotonin science

When we are in love or think we are, chemicals tend to race around our brains and bodies. This topic remains a strong source of fascination for scientists, with new research being made into it all the time. Researchers have been using solutions including functional magnetic resonance imaging (fMRI) to learn more about the chemistry of love. This enables them to actually see what happens to people’s brains when they view photographs of people that they feel attracted to. The research shows that more blood flows to parts of the brain with high concentrations of dopamine receptors. High dopamine levels are linked to norepinephrine, and this can make us feel hyperactive, unable to sleep and focussed on one particular goal or issue. This explains why people who feel intensely attracted to someone new often having trouble thinking about anyone or anything else.

Love and chemistry: when excitement is lacking

Many people often end relationships because they feel there is “no chemistry” between themselves and the other person. Even if the person seems to be a good match on paper, they have plenty of things in common and you regard them as good looking, the magic may just not be there. Science could be the reason why you feel there is simply something missing. You may feel like you are simply not emotionally connected to them and may even find it hard to talk to them. You may not feel drawn to them and you may find it impossible to really bond with them.

How long should I wait?

If you have started a new relationship with someone but are worried there is “no chemistry”, it could be good to wait a while before you decide to bring things to a close. Many great relationships have blossomed over time after a lukewarm start. Chemistry is not always instant, and it can take some time. Chemistry is often confused with lust, yet it is about feeling emotionally compatible with someone as well as sexually attracted to them. Physical chemistry is about more than simply physical attraction, and you can find someone physically attractive without actually being attracted to them.

Give things a chance

If you enjoy the first date with someone but don’t feel any real magic, it may well be worth heading out for a second or even third or fourth date to see if things change. If you still don’t want to be physically close to them or are able to go hour after hour without thinking about them, chances are you are correct that the chemistry is not there and it’s better to pursue another idea. Although scientists have claimed that it takes just it takes 7 seconds for men and 12 for women to decide if they like each other, many people have found themselves in serious, healthy and long-lasting relationships with people they weren’t initially bowled over by. Some claim it could take as little as three seconds to decide if we find someone attractive.


A whole host of things happen to our bodies and brains when we start to feel a little obsessed with someone new. In most cases, this will simmer down the more we get to know them, but if you do get over the initial rush and still feel mutually attracted to each other, you may well stay together for the long haul.

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