If someone asks you what you apply every day to your skin, you might be tempted to list the skincare products you have in your bathroom: moisturiser, cleanser, serum, sunscreen, exfoliator, etc. But what are these products made of?

According to a recent study, the typical person applies an average of 12 different products – containing over 160 chemicals – on their skin daily. While we all tend to just trust the label, it is important to understand what these chemicals are and how they impact our skin microbiome.

After all, the skin is the body’s largest organ, and one of the most important ones. Repeatedly applying disruptive chemicals can affect our skin health, hormones and skin microbiome.

Today, there are over 1,300 chemicals banned by the EU because they are suspected to be harmful. While you might not be able to avoid all the ones that are not banned, you can do your best to avoid the most common ones – here are the ones to look out for.

Synthetic colours

Commonly found in makeup and colourful skincare products, synthetic colours often appear in the ingredient list as FD&C or D&C (Food, Drugs, and Cosmetic-Approved), followed by an identification number.

Synthetic or artificial colours in skincare products are not uncommon, and they can increase the risk of skin sensitivity and irritation. In fact, these chemicals can throw the beneficial bacteria in your skin microbiome off-balance and close your pores, making acne flare-ups more common.


Parabens are one of the most common ingredients found in makeup products, body washes, deodorants, moisturisers, and facial cleansers. Parabens are identifiable by their names:

  • Methylparaben
  • Propylparaben
  • Butylparaben
  • Ethylparaben

While they are used as preservatives, they act in the body similarly to the hormone estrogen (estrogen-mimickers), causing disruptions to the hormones. Preservatives such as parabens, when absorbed by the skin, can impair the growth of beneficial bacterial colonies and promote the proliferation of harmful microorganisms, thus affecting the skin microbiota’s balance.

Synthetic fragrances and perfumes

Synthetic fragrances are often found in perfume, deodorants, hair products, moisturiser and many more lotions and creams. Many chemicals are grouped under this name – they are listed in the ingredient list as “Synthetic fragrances” or “Synthetic perfume”. The full list of synthetic fragrances in products is often not disclosed because manufacturers use this umbrella term to protect their recipes.

These chemicals can have different effects on the skin microbiome – depending on what chemicals are included! Even without the addition of harmful ingredients, synthetic fragrances are linked to allergic reactions and chronic skin conditions such as dermatitis.

SLS & SLES (Sodium Lauryl & Laureth Sulfate)

Sodium Laury (SLS) and Laureth Sulfate (SLES) are the most common surfactants in today’s skincare products. They are recognisable by their names (SLS and SLES) and they are commonly found in:

  • Soaps and shampoo
  • Body wash and lotions
  • Toothpaste and mouthwash
  • Washing liquid

Surfactants have the ability to lower the surface tension between ingredients. They are used as a foaming agent in washes and shampoos.

While the concentration of SLS and SLES vary from 1% to 50%, it is estimated that the great majority of household products contain one of these ingredients. On the skin, surfactants can disrupt the lipids composition and quantity, removing the skin’s natural barrier and leaving it exposed to external agents.


Discovered in 1859, formaldehyde is today used in many cosmetic and skincare products, including:

  • Some skincare products
  • Nail polish and nail polish remover
  • Some toothpaste and dental care products
  • Perfumes that include synthetic fragrance

Formaldehyde can be recognised under names such as Formalin, Formic aldehyde, Methanediol, Methanal, Methyl aldehyde, Methylene glycol, or Methylene oxide. When applied to the skin, formaldehyde can cause allergic reactions.

Propylene glycol

Propylene glycol, or PG, can be found in liquid foundation, moisturisers, lipsticks, shampoos, conditioners, and spray deodorants.

You can pinpoint PG in your products by looking for its name, Propylene glycol. Sometimes it can also appear under the names 1,2-propanediol or propane 1,2-diol. In foods, it is listed as E1520, but it can also appear under other nomenclatures.

Propylene glycol is a chemical usually added to skincare products and cosmetics to increase moisture retention. While most people do not tend to have reactions to this chemical, propylene glycol does penetrate through the deepest layers of the skin. Prolonged exposure to PG has been linked to increased sensitiveness, redness of the skin, dermatitis, and allergic reactions.

The right skincare can make a difference

We don’t often stop to think about the chemicals that we put on our skin. However, prolonged exposure can leave your skin unprotected, disrupt its natural barriers, and affect your skin microbiome.

That is why you should start your journey towards a personalised skincare routine by understanding the skin you’re in and your microbiome composition. At Skin Trust Club, we understand the power of the right skincare routine and we are here to help you select a personalised solution that works for your unique skin type. Start by taking the Skin Trust Club skin microbiome test today and begin your journey to healthy, glowing skin.