1. Hair grows back thicker, darker, and faster when you shave it.
False: "Shaving hair is just cutting the end, so it has no effect on root and therefore no effect on growth," says Dr. Heidi Waldorf, the director of laser and cosmetic dermatology at the Mount Sinai Medical Center in New York City. "But shaved hair may look different because the ends are blunt, not tapered."
2. The average woman consumes 6 pounds of lipstick in a lifetime.
False: "The average lipstick ingestion amount is 24 milligrams or 0.024 grams of lipstick. If you wear lipstick every day, then on average, you would consume 8.76 grams per year. Let's assume a lifetime is 70 years: Multiply 8.76 by 70 and you get 613.2 grams of lipstick ingested over a lifetime — or 1.35 pounds. To ingest 6 pounds would mean consuming about 680 tubes of lipstick," says cosmetic chemist Ni'Kita Wilson.
3. Brushing your hair too much will make it fall out.
False: "It actually stimulates the follice and helps the hair to grow," says celebrity hairstylistJulian Farel, who recommends using Janeke brushes which have silicone bristles to massage and encourage regrowth.
4. Sleeping on your stomach gives you wrinkles.
True: "More pressure means more sleep lines which become permanent over time. Unfortunately, it's nearly impossible to change the way you sleep," says Dr. Waldorf, who recommends switching to a copper ion Iluminage pillowcase instead.
5. Wearing hair ties damages your hair.
True: "If they're too tight, they can pull out too much hair and strain and damage the follicle, causing hair loss. Also, wearing them for long periods causes headaches," says Farel, who warns against sleeping in hair ties.
6. Toothpaste is an effective way to clear up pimples.
False: "You're better off using over-the-counter benzoyl peroxide, salicylic acid or resorcinol," says Dr. Waldorf. "Over time, the fluoride in toothpaste applied to the skin could actually aggravate acne."
7. Exercise gets rid of cellulite.
True and false: Hormones and genetics are the leading cause of cellulite, so exercise won't get rid of cellulite, but may reduce it. "Cellulite is fat, so the less fat you have, the less noticeable it will be; however, even very fit, toned women can have it," says Dr. Waldorf.
8. Plucking stray gray hairs causes more to grow in their place.
False: "This is something I heard from my grandmother, but there is no viable proof," says Farel. In fact, plucking can do the opposite and create bald patches, so cover grays with cut or color instead.
9. Running leads to sagging skin.
False: Unless you're running outdoors without sun protection, it absolutely won't cause wrinkles or sagging skin, says Waldorf.
This article originally appeared on Harpers Bazaar.
