En español | Why does the erotic heat couples feel at the start of a relationship cool over time, making sex routine? The answer may be more matter of chemistry than of romance.

See also: Improve your sex life.

Doing exciting new things can help you have better sex. — Photo by Ocean/Corbis

Dopamine, a chemical in our brains, is the key player in this drama. When people fall in love, their dopamine levels soar, causing all sorts of reactions: Your heart pounds. You lose your appetite. You can’t sleep. And you become obsessed with your object of desire. In short, you become head-over-heels in love.

As the dopamine rises, so does testosterone, the hormone that fuels sexual desire in both men and women. But over time — six months to a year or so — dopamine levels return to normal, and burning desire morphs from Fourth of July fireworks to Thanksgiving’s cozy affection.

But there’s good news for the romantic in us all: You can tweak your dopamine levels so that even long-married couples can enjoy the erotic heat of a second honeymoon.

How? In a word, novelty. In one experiment, psychologists gave 28 couples questionnaires that explored their feelings for each other. Then half the couples completed a tedious task, while the others engaged in a new and exhilarating activity. Afterwards, everyone completed the questionnaire again. The couples involved in the exciting activity reported greater relationship satisfaction, and said they felt more passionately in love. Credit their novelty-induced spike in dopamine.

Here are four effective ways to boost your dopamine and break out of sexual ruts:

1. Do exciting new things together.
“This is standard relationship-enhancement advice,” says sex therapist Louanne Weston. “It’s no coincidence that weekends away are often called ‘romantic getaways,’ or that sex often feels more passionate in hotel rooms. You’re in new and different surroundings. That’s exciting and romantic — and it spurs the libido.” Of course, there are different grades of “new,” from a new restaurant around the corner to a month in China. The newer the activity, the greater the increase in dopamine. But any shared new experience can echo in the bedroom.

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