It doesn’t matter whether you have a bob , dreadlocks or a cap of hair a la Angela Davis. The hygiene rule is the same for everyone: you need to wash your hair regularly, and the frequency depends on how quickly your hair gets dirty. We’ll tell you about all the nuances of scalp cleansing from a dermatological point of view and explain why some folk remedies are so popular. Spoiler: some of them really work!
Why does hair get dirty?
The hair that we see is a dead structure. It produces nothing, but only accumulates dust, dirt and residues of styling products on its surface. Sebum, or skin fat, makes hair greasy and unpleasant to the touch. This is not one substance, but a whole complex of fats, carbohydrates and waxes that:
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prevent moisture from evaporating from the skin’s surface,
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They do not allow bacteria to pass through and do not allow them to multiply on the skin of the face, body and head.
The amount of sebum directly depends on the production of hormones . This parameter is programmed by genes, and we cannot influence how much sebum the sebaceous glands secrete. But adapting and choosing the right products to keep your hair clean is still possible.
Another important factor that affects the oiliness of the scalp is age . But it is also closely related to hormones: the more androgens the body produces, the more active the sebaceous glands on the surface of the skin are, and the faster the hairdo loses its fresh look. Androgens are considered male hormones, but they are also produced in women, they just turn into estrogens later.
Youth is the peak of androgen levels in the blood, so young men and women notice increased oiliness of hair during this period of life. And children and the elderly can wash their hair less often, because their sebaceous glands work at half capacity. In general, sebaceous glands work for our benefit – they moisturize the scalp, prevent its dryness and itching.
Is it possible to train your hair to wash less often?
“The less you wash your hair, the less greasy your hair will be.” This is a myth. You can’t train your sebaceous glands to produce less oil. If you don’t wash your hair for a week or even a month, you’ll see for yourself. Your hair will look like icicles if you have oily skin, or like the result of a bad perm if you have dry skin. If you have dandruff on your scalp , washing it infrequently will only provoke it to appear. But poor hygiene in itself is not the cause of dandruff .
How often should you wash your hair?
There is no clear and uniform answer to this question for everyone. You need to wash your hair as needed and taking into account your scalp type.
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If your hair gets dirty and starts to look unkempt 1-2 days after washing, then you probably have an oily scalp type. In this case, it is recommended to wash your hair every day or every other day.
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If your hair looks clean for 3 days or more, you either have normal or dry skin. You can wash your hair less often, 2-3 times a week is enough.
Tip: If you play sports, always wash your hair after training. Intense physical activity provokes the production of hormones, and hormones stimulate the sebaceous glands to work more actively.
How does hair shampoo work
Washing your hair starts with shampoo. Its main and only task is to cleanse the scalp of dirt and sebum. The product cannot guarantee restoration, strengthening or acceleration of hair growth, even if the composition includes nourishing oils, vitamins and brewer’s yeast. A 2015 review article in the Indian Journal of Dermatology explains why you should not place your hopes on shampoo: contact with oils and other useful components is too short to affect the structure and quality of the hair. Shampoo can only affect the cleanliness of your hair and give it a pleasant smell.
At the heart of any shampoo is a detergent, or surfactant. This group of substances has given us dishwashing detergents, window cleaners, glass cleaners, and other products that make our lives easier and save time at the sink.
The superpower of these substances is to simultaneously attract and repel water, and in the process wash away all the greasy and dirty stuff from the surface of objects, including hair. When we apply shampoo to our hair, surfactants cling tightly to the molecules of sebum, and water cannot separate them. But if you direct a stream of water at your hair in shampoo, the “shampoo + fat” couple will easily fly off into the drain in the shower.
Without surfactants, we will not achieve clean and fresh hair. They are contained in absolutely all shampoos. If you see a product marked “SLS-free” on a store shelf , it means that the shampoo does not contain only sulfates – they are replaced by another group of surfactants. Products without SLS – lauryl sulfate and laureth sulfate – are suitable for those who suffer from allergies, dermatitis, or owners of dry scalp. They cleanse hair more gently and delicately, unlike their counterparts with sulfates inside.
To check whether the shampoo you bought or saved in your online shopping cart contains SLS or substances that provoke allergies or other unwanted side effects, we recommend that you seek help from the EWG’s Skin Deep website . This database includes more than 65,000 cosmetic products and components with an assessment of their level of safety for your health. The site is supported by the non-governmental Environmental Working Group in the United States.