Some Common Sense about Shampoo Containing Silicone Oil

Sep 24, 2021

Previously, there was a saying on the Internet that 90% of shampoos contain an ingredient called "polydimethylsiloxane", which is the so-called silicone oil smoothing agent. Rumors say that because this chemical substance of silicon or dimethylsiloxane fills the gaps between the hair scales, the hair is very smooth after washing, but due to the impermeability and inertness of silicon, it will Clog the pores, it is easy to make the scalp itchy, even hair loss, hair loss and so on. Let us know some common sense about silicone oil shampoo.
Why use silicon.
Except for baby products in supermarkets, almost all shampoos contain silicone oil. Why should silicone oil be added to shampoo? Will silicone oil block hair follicles and damage hair?

Silicone oil is sticky and malleable, and has a moisturizing and softening effect on hair. Hair grows from the hair follicles in the scalp, and the main component is keratin. There are many jagged cuticles on each hair. When the hair scales are damaged, they will turn up, which will increase the friction between the hairs, causing the hair to become tangled together, and more friction will aggravate the damage of the hair scales. When you wash your hair, the silicone oil in the shampoo is attached to the gaps of the hair scales, filling the surface of the hair, and the hair will feel very smooth.

The purpose of washing hair is to get rid of the dust on the hair and scalp, and to wash off excess oil. However, when washing the hair, the hair absorbs water and swells, becomes moist and soft, and the protective oil outside the hairy skin is also washed away. The anionic surfactant, which is the raw material of shampoo, cleans the dirt on the head, but it is absorbed on the hair under the action of water. After the hair is dried, the hair will explode due to the repulsion of the same sex. If it is combed with a plastic comb at this time, it is easy to generate static electricity. The problem of anions can be solved comprehensively with cations, such as quaternary ammonium salt type cationic surfactants. But these can not solve the problem of hair scale damage. The chemical reagents, heat and ultraviolet rays of the sun used when dyeing perm damage the hair even more.

Later, it was discovered that grease can solve this problem. The grease lubricates the hair and reduces hair damage during combing. It can be found that the sweet-scented osmanthus oil and hair conditioner used by people in the past were mainly fats. PDMS (polydimethylsiloxane) can be attached to the hair well due to its inertness and adsorption, filling the damaged parts of the hair scales, and making the surface of the hair smoother, which is the so-called repair effect. Hair that has used silicon-containing shampoo is brighter, easier to comb, and stronger and smoother. PDMS can also keep the moisture content of the hair stable through the formed protective layer.
The effect of silicone oil on scalp health.

Message about hair loss caused by silicone oil. Silicone oil is a macromolecular substance and will not be absorbed by hair follicles. There are not many silicone oils in shampoos. Under the cleaning action of surfactants, plus a lot of water rinse, there is basically no residue on the head. In fact, there are many reasons for hair loss, such as seborrheic alopecia caused by endocrine disorders, mental stress, and even postpartum physical hair loss. Blocked hair follicles are not the cause of hair loss.

The hair care effect of PDMS is obvious, especially for the hair that is often permed and dyed, and the damage to the hair scales of often permed and dyed hair is more serious. Because silicone oil works by adhering to the hair to fill the damaged and splayed hair scales, people are worried that it will also deposit on the scalp, block the pores, and cause irritation, inflammation, acne, hair loss and other adverse effects. .

Silicone oil is safe to use in cosmetics because it is not irritating to the skin. Although it can form a hydrophobic film on the skin, it is breathable. It does not cause acne, acne, hair loss, allergies, etc. Instead, it is often used in products that indicate a non-acne or oil-free products. This is its advantage over traditional grease.

Most shampoos will add a small amount of PDMS, which can achieve some hair care effects while cleaning the hair. In fact, just as its hair care effect is very limited, the possibility of PDMS remaining on the scalp and clogging the pores is also very low. Because the PDMS content in the shampoo is very small, below 1%, almost all of it is removed under the action of the cleansing anionic surfactant and rinsed with a lot of water. For hair conditioners and hair masks that contain more silicone oil, the method used is to apply only to the end of the hair away from the scalp. First, it can save money. Second, the hair roots are generally damaged. Little, basically no care, thirdly, if it is rubbed on the roots of the hair, it is not only greasy but also heavy and flat.

Now there are new components that improve the structure of PDMS, such as ether or amino groups. These new elements have stronger binding ability to hair and greater water solubility than PDMS. Products containing these new ingredients can adhere more effectively with fewer residues. So friends who are confused about rumors don’t have to worry too much.Because PDMS will adhere to the hair, the hair will become thicker and heavier, and at the same time, the static electricity between the hair will be reduced, so after the hair dries, it will not be fluffy or even collapsed. For people with short hair and soft hair, this may be unsightly, so such people can choose shampoos that do not contain PDMS.