How sulfates and silicones in shampoo can negatively affect hair growth and cause hair loss

Choosing the right shampoo is an important part of maintaining healthy and strong hair. Unfortunately, many common shampoos contain ingredients that can actually have the opposite effect – contributing to hair loss and reduced hair quality. Two of the most problematic substances are sulfates and silicones.

In this article, you’ll learn:

Sulfates are cleansing chemicals added to shampoo to create lather. The most common ones are:

• Sodium Lauryl Sulfate (SLS)
• Sodium Laureth Sulfate (SLES)

They effectively remove oil and dirt, but are also very harsh and can dry out both the scalp and the hair.

• Dries out the scalp and irritates the skin
• Damages the hair’s natural protective barrier
• Can lead to inflammation of the hair follicles
• Contributes to increased hair loss in some individuals

A dry and inflamed scalp is not a healthy environment for new hair growth, and it increases the risk of existing hair falling out.

Silicones are synthetic ingredients added to shampoos and conditioners to give a “soft” and “shiny” finish. Common types include:

• Dimethicone
• Cyclomethicone
• Amodimethicone

• Forms a coating around the hair strands that prevents moisture and nutrients from penetrating
• Creates a false sense of shine and softness
• Can build up on the scalp and block pores
• Restricts oxygen supply to the hair follicles → impaired hair growth

A scalp that cannot breathe and cleanse itself naturally creates an environment where hair grows slowly or not at all.

Both of these ingredients affect the health of the hair follicles:

• Sulfates can cause inflammation in the scalp and lead to damage to the hair follicles.
• Silicones can “encase” the follicles, reducing nutrient absorption and blocking natural growth.

Over time, this can lead to diffuse hair loss, reduced density, and poor quality of the hair that does grow.

When looking for hair care products that are gentle on the scalp and support hair growth:

1. Sulfate-free
   • Look for labels that say “SLS-free” or “sulfate-free.”
2. Silicone-free
   • Avoid products with ingredients ending in “-cone” (e.g., dimethicone).
3. Mild cleansers
   • Ingredients like Coco-Glucoside or Decyl Glucoside are gentle and non-stripping.
4. Natural extracts
   • Products containing caffeine, biotin, rosemary, or aloe vera can help stimulate hair growth.
5. pH-balanced
   • A shampoo with a pH around 5.5 is the most gentle on the scalp.

Many people experience reduced hair quality or even hair loss without realizing it could be due to the shampoo they’re using. While sulfates and silicones may make the hair look shiny and clean on the surface, they can, over time, damage the scalp environment and contribute to hair loss.

By choosing a sulfate- and silicone-free shampoo with gentle ingredients, you give your hair the best possible conditions to grow strong, thick, and healthy.

1. Journal of the Society of Cosmetic Chemists
Title: The Effect of Surfactants on the Skin Barrier Function
Summary: This study explains how sulfates like Sodium Lauryl Sulfate (SLS) damage the skin’s lipid barrier and can cause irritation, dryness, and inflammation – effects that also apply to the scalp.

2. International Journal of Trichology
Title: Hair Cosmetics: An Overview
Authors: Lidia Rudnicka, Dorota Olszewska et al.
Summary: The article discusses how cosmetic ingredients, including silicones, can affect the hair and scalp. It notes that silicones can lead to buildup, which impairs scalp function and oxygen exchange.

3. Contact Dermatitis Journal
Title: Irritant Contact Dermatitis from Shampoo Ingredients
Summary: A clinical study showing that sulfates in shampoo are a common cause of contact dermatitis—an inflammation that can contribute to hair loss in sensitive individuals.