As the days get longer and the weather heats up, many people's minds turn to skin -- perhaps because they plan to show more of it in the coming months.
With that in mind, we approached a number of myths about how to help your skin look its best. Some of these are warnings you heard from your mother, while others are the type you might have heard from your friend who subscribes to 20 magazines. Some are proverbial old wives' tales, others have solid medical evidence behind them, and a few are true -- but misleading.
Does shaving really make your hair grow back thicker? Can squinting give you wrinkles? Will dry brushing really help you get rid of your cellulite? Does getting a base tan in a salon help you avoid sunburn?
These myths have taken hold as standard advice on skin care. But do they stand up to the scrutiny of dermatologists?
Fact or Myth? Shaving makes hair grow back thicker.
"That's definitely a myth," said Dr. Arielle Kauvar, a clinical associate professor in NYU's department of dermatology.
But there's a reason why shaving might appear to have that result.
"When you shave, you're seeing the blunt edges of the hair regrow all at the same time, so there's an appearance of being thicker, but there's no difference in the diameter or the density of the hair," Kauvar said.
Hair doesn't seem to grow in as thick in waxing, because the entire follicle is removed, so the hair coming back in is growing in different cycles. As a result, it does not appear to be as dense. Also, the hair is tapered at the end, so it does not appear to be as thick.
Fact or Myth? Exfoliating can slow hair growth.
Doing something to your skin doesn't seem to affect something that grows below it.
"Exfoliating the surface of the skin -- it's not going to change the metabolism of the follicle underneath the skin," said Dr. Ronald Brancaccio, director of the Skin Institute of New York.
The only current treatment available to slow hair growth is the drug Vaniqa, which is applied topically to reduce facial hair growth in women. It works by blocking an enzyme that enables hair follicles to grow.
A number of illnesses can also lead to a temporary loss of hair. These include thyroid problems and a condition known as telogen effluvium.
Typically, 20 percent of hair is in the resting phase -- where it is not growing -- at any given time. Illness, trauma or childbirth can lead to telogen effluvium, where a greater percentage of the hair is pushed into that resting phase, making it seem like hair fell out overnight.
Fact or Myth? All wrinkles form by age 25 -- they just start to show later.
This is known to be a myth largely because activities after 25 -- like spending more time out in the sun -- can lead to an increase in wrinkles.
"If you get a lot of sun exposure, you're definitely going to get more wrinkles," said Dr. Zoe Draelos, a dermatologist in private practice and a researcher in High Point, N.C.
Wrinkles are the result of a loss of collagen, the main structural protein of the skin. As you age, the body begins to produce less of it, which keeps skin from being as firm as it was when you were younger.
But while that decline in collagen happens to everyone, and wrinkles will form along the lines that are moved in facial expressions, sun exposure breaks down collagen even more, leading to wrinkles that otherwise might never have happened.