Why is frequent washing of hair with shampoo harmful?

Daily washing of hair with sulfate shampoos (Sodium Lauryl Sulfate, Sodium Laureth Sulfate, and their derivatives) can negatively affect the scalp, hair, and overall health. This is related to both the chemical properties of sulfates and the physiological reactions of the skin.

Why sulfates can be harmful

Sulfates are surfactants that effectively remove sebum, dirt, and residues of styling products. The problem is that they act too aggressively:

• strong degreasing — along with impurities, lipids that form the natural protective barrier of the scalp are removed;
• destruction of the hair's lipid layer — the cuticle is raised, leading to increased brittleness and moisture loss;
• chemical load — with constant contact with the scalp and micro-damages, transcutaneous absorption of individual components can occur, creating a toxic load with prolonged exposure.

The mechanism of the scalp's "protective" reaction

With daily washing of lipids, the skin receives a signal of barrier damage. In response, the sebaceous glands begin to produce more sebum to restore the protective layer. A vicious circle arises: the more often sebum is washed away by aggressive shampoos, the more actively it is produced.

This leads to hair becoming greasy quickly, causing the person to wash their hair even more often — exacerbating the problem.

Connection to hair loss

With constant irritation of the scalp:

• The hair follicles become inflamed and damaged — chronic irritation from surfactants increases skin sensitivity and can cause micro-inflammations around the follicle.
• Blood flow in the dermis is disrupted, resulting in follicles receiving fewer nutrients.
• The Malassezia fungus (formerly Pityrosporum ovale) is present on the scalp. Normally, it is controlled by the lipid balance and the skin's immune system. Sulfates aggressively remove lipids and damage the stratum corneum of the epidermis. Without the lipid layer, the skin becomes more vulnerable, pH may shift, creating ideal conditions for the excessive proliferation of Malassezia. This leads to seborrheic dermatitis and accelerated hair loss.

Hair care recommendations:

• Wash hair with sulfates no more than 1–2 times a week (if necessary — only the root area). On other days, gentle sulfate-free shampoos (with cocamidopropyl betaine, glycosides) can be used.
• Maintain scalp health with a physiological pH (4.5–5.5), masks, and lotions containing ceramides, panthenol, and amino acids.