1. WRITE OFF WRINKLES Stress hormones and anti-stress hormones are like a seesaw in your body, and sex - specifically orgasm - gives that seesaw a giant push in the right direction thanks to a trifecta of hormones: beta-endorphin, an opiate and painkiller; prolactin, a relaxation inducer; and oxytocin, which makes you want to cuddle. Endorphins and growth hormones flood the body after orgasm, healing damage from the sun, smoking, and cortisol, which destroy collagen and create wrinkles. In a fun few minutes, sex wipes out the inflammatory molecules that age skin.
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2. SOFTEN SKIN Think of how you look right after sex: dewy cheeks, pink lips, and shining eyes. The bright-eyed look lasts for days, as does sex's other skin-friendly side effect: When you sweat, natural oils, like linoleic acid - a moisturizer also found in safflower and olive oil - are released, lubricating cells and hydrating skin.
3. LOOK ALIVE Sleep is free cosmetic medicine, and sex is an amazing sleep inducer. Those feel-good chemicals linger after orgasm, helping you fall asleep more quickly. Post-sex sleep is restorative, so you'll wake up refreshed, with reduced under-eye circles and puffiness. Adding sex to your bedtime routine can also help resolve sleep issues.
4. FEEL THE BURN Even without a climax, sex and kissing work wonders: heart rate and circulation increase, and blood floods your organs and skin. Deep breathing controls stress and send oxygen throughout your system. Sex burns about as many calories as the same amount of time spent weight training or walking; even a measly smooch stimulates 30 facial muscles. You burn eight to 12 calories per minute of kissing (more than you burn in a minute of walking). That exercise improves everything from cholesterol levels to mood - without your going anywhere near a Spin class.
5. FAKE IT TILL YOU MAKE IT Orgasm is key to attaining sex's benefits. If you don't have one, you release fewer good-for-you hormones. Single or celibate? Masturbate or exercise - a half hour of vigorous walking, jogging, or weight lifting triggers healing endorphins. A quick downward-dog stretch brings blood from your core to your head for that flushed, pink-cheeked look. Or go the makeup route. Blush is key, and so is moisturizer, mascara, and lip gloss. But nothing beats the real thing.