How many times a week do you wash your hair?
Every dermatologist and hair stylist has a different recommendation.
It’s hard to know how often is too much.
Or is it? According to the director of Boston Medical Center, it’s actually pretty easy to know exactly how often to wash your hair…
How to Wash Your Hair Right
Before you get into how often to wash your hair, you need to understand why you’re washing the hair in the first place.
Your hair is exposed to a wide variety of pollutants throughout the day. There’s all the smog released by the vehicles you pass on the street. You’re exposed to cigarette smoke every time you walk by someone smoking. Then there’s all the dust and particles blowing in the wind. If you spend time at the beach or in the desert, there’s sand and dirt as well.
Your hair gets dirty, but it’s not just the dirt that you’re washing out. You’re also getting rid of the skin oil produced by the sebaceous glands in your scalp. The oil (known as sebum) serves as a protective layer for your hair, ensuring that sun, debris, and pollutants don’t damage the individual strands. But everyone’s scalp produces a different amount of sebum. Too much skin oil and your hair starts to look greasy and dirty. That is when you usually take a shower.
But every time you wash your hair, you are exposing the strands to damage. Your body reacts by increasing the production of skin oil, leading to greasier, dirtier hair. Excess washing can lead to a dry scalp and excessively oily hair, an odd combination that leads to an unhealthy scalp and easily damaged hair.
- Style — How much time and effort do you invest into styling your hair? The more you use chemicals to straighten, color, curl, or bleach your hair, the weaker the hair is. You need all that skin oil to protect the hairs, so you need to wash it less frequently than you would hair that is undamaged by styling products.
- Skin Type –– How much skin oil does your scalp produce? Some people have very oily skin, and they need to shower more often in order to reduce the presence of skin oil in the hair (though not to the point that they dry out the skin). If you have normal skin on your scalp (not too dry nor too oily), you should be washing no more than twice per week. For those with dry skin, once or twice a week is also a good amount of washing.
- Texture –– The texture of your hair determines just how fast the oil works its way throughout your hair. Curly and coarse hair tends to slow down the spread of sebum, meaning that it is less common for people with coarse or curly hair to have problems with excess grease. Shampooing once per week is more than enough for curly or coarse hair. For those with straight or fine hair, it may be a good idea to shampoo two or three times per week. The sebum seeps through the hair more quickly when it’s straight or fine, meaning greasier hair!
It’s all about being smart with your hair care.
-  http://goaskalice.columbia.edu/how-often-wash-hair
-  http://www.bumc.bu.edu/derm/lynne-j-goldberg-md/