Updated 03 March 2014

Love chemistry

In the 21st Century love isn't simply girly mushy romantic fluff any more. Researchers are gradually uncovering the hard science and chemistry behind love. It's a drug!


After generations of poets muttering unsubstantiated claims about magic love potions and pop singers telling us that we’re “addicted to love”, scientists have finally found conclusive evidence that love is, in fact, a drug! They have identified a cocktail of potent natural stimulants produced by our own bodies which make us fall in love and keep us together.

Of course it’s not all just chemistry. Things romantic are forever complicated by the participants’ genetic make-up, their religious, social and cultural baggage and sheer bloody luck. And with all of those in the mix it still takes a seriously special spark to really ignite the flames of passion. But in the end, the science boffins tell us, the earth ain’t gonna move between two people without the right mix of hormones at the right time.

American scientist and author Helen Fisher has helpfully subdivided the whole business of human romantic love into three stages, each with its own specific body chemicals: lust, attraction and attachment.

Falling in lust

Biochemically-speaking, the first step of falling for someone – the sheer animal craving for physical contact, kissing, fondling, canoodling and sex – is fuelled predominantly by the sex hormones oestrogen and testosterone in both women and men. The effects have been described as being comparable to those associated with taking opiates like heroin!

As far as the psychology of the process goes, studies have shown that it typically takes people between 90 seconds and four minutes to fall for each other. All you guys out there will be relieved to hear that exactly what you say during this early stage of proceedings is pretty much irrelevant - it’s how you say it that matters: 55% is to do with your body language and 38% involves the speed and tone of your voice.

Special attraction

The process of falling in love with someone – those feelings of obsession, exhilaration and elation – appears to be controlled chiefly by the bodily drugs adrenalin, dopamine and serotonin. It’s the rush of adrenalin that activates the racing heart, the dry mouth and the sweating anytime you’re near you’re new love interest.

Newly love-struck couples have also been found to have high levels of the feel-good chemical dopamine. It’s a key ingredient in the brain’s reward system, is associated with extra energy and stamina, highly focused attention and a reduced need for sleep and food. It has a similar effect on the brain as cocaine and is linked to pleasure and addiction. Dopamine is what makes lovers come back for more again and again.

Comparatively low levels of serotonin, which controls impulses, passions and obsessive behavior, explain why lovebirds struggle to think of anything else but their new squeeze. Biochemically, the effect is equivalent to that found in people suffering from obsessive compulsive disorder.

In it for the long haul

If dopamine and serotonin make us fall in love, the two hormones responsible for keeping us together are oxytocin and vasopressin, both of which are stimulated by sex and orgasm. The “cuddle hormone” oxytocin causes the release of endorphins, the body’s natural opiates. Produced by the brain’s hypothalamus, oxytocin is thought to deepen feelings of closeness, emotional unity, security, comfort and attachment. The other important pair-bonding hormone, vasopressin, similarly encourages long-term commitment and closeness.

Love addiction

Scientists have found that brain scans of people who are deeply in love share much in common with those of people experiencing the euphoria induced by drugs such as cocaine. Feelings of anxiety, sleeplessness and depression which commonly accompany an extended separation from your lover resemble the withdrawal symptoms suffered by regular drug users.

The good news is, of course, that while love may be just as addictive as illegal stimulants, it’s not nearly as damaging to your health. Love’s the one drug everyone’s encouraged to be addicted to!

Helen Fisher, the love scientist, has been to the fantastic annual TED conference in California not once, but twice. Watch her explain her findings and theories in these two enlightening video clips – they’re well worth the wait of the download:

Books about the chemistry and psychology of love:

Why We Love: The Nature and Chemistry of Romantic Love by Helen Fisher

Falling in Love: Why We Choose the Lovers We Choose by Ayala Malach Pines

The New Psychology of Love edited by Robert J. Sternberg and Karin Weis

The Secret Psychology of How We Fall in Love by Paul Dobransky

Brain Sex: The Real Difference Between Men and Women by Anne Moir and David Jessel

The Mating Game: A Primer on Love, Sex, and Marriage by Pamela C. Regan


(Andrew Luyt, Health24, April 2010)


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