Valentine's Day: 5 facts you might not know about love and sex

(Uriel Sinai/Getty Images)

Underneath the gaudy red roses, stuffed teddy bears clutching tacky velvet hearts, and eye-wateringly expensive weekend getaways, Valentine's Day is a wonderful chance to celebrate love.

And to mark 14 February, here are five things you might not know about love and sex.

Aphrodisiac food

Chocolate contains phenylethylamine, a chemical that causes the release of dopamine and norepinephrine, the key hormones that help us fall in love.

(PIERRE ANDRIEU/AFP/Getty Images)

Instant attraction

It only takes between 90 seconds and four minutes to decide if you fancy someone, and 55 per cent of attraction is based on body language alone.

Monogamous animals

Only three per cent of mammals mate for life. Animals that do find a lifelong partner include gibbons, swans, wolves, albatrosses, penguins, eagles and termites.

Penguins are among the few monogamous animals (Getty)

Natural painkiller

Simply looking at a photo of the one you love, or even thinking about them, increases levels of oxytocin, the body’s natural painkiller.

Broken Heart Syndrome

Also called stress-induced cardiomyopathy, it is caused by an emotionally stressful event, such as a break-up, and causes sudden intense chest pain.

Jo Stas writes for How It Works Magazine. Follow the magazine on Twitter: @HowItWorksmag