5 ingredients to avoid in your shampoo, and what to choose instead

Most shampoos contain ingredients that make your hair feel smooth in the short term but dry out the scalp, damage hair cuticles or end up in the environment over time. The five most common are SLS, silicones, parabens, mineral oils and microplastics.

• SLS (sodium lauryl sulphate): aggressive cleanser that dries out and irritates the scalp
• Silicones: coat the hair without nourishing it and build up in the hair shaft
• Parabens: synthetic preservatives that can disrupt the hormonal system
• Mineral oils: petroleum derivatives that weigh down hair and clog the scalp
• Microplastics: plastic particles that end up in water and never fully break down

Below you will find what each ingredient does, how to recognise it on the label and which natural alternative works better for your hair and scalp.

1. SLS and SLES: aggressive cleansers that do more harm than good

Sodium lauryl sulphate, better known as SLS, is the ingredient responsible for the rich lather in most shampoos. It is a powerful cleanser that effectively removes grease and dirt, but goes too far in doing so. SLS does not only remove excess oil but also the natural fats that keep your hair and scalp healthy.

The result: a scalp that feels dried out responds by producing more sebum. Hair initially feels clean but soon becomes greasy again. You wash more often, the scalp becomes increasingly unbalanced. SLES (sodium laureth sulphate) is a slightly milder variant but has a comparable effect on the skin barrier.

On the label you recognise it as: Sodium Lauryl Sulfate or Sodium Laureth Sulfate. The natural alternative is a mild surfactant formulation based on sugar derivatives or coconut oil, such as Sodium Cocoyl Isethionate or Cocamidopropyl Betaine. These cleanse effectively without stripping the scalp.

2. Silicones: a smooth feeling with a price

Silicones are synthetic polymer compounds that apply a coating to the hair shaft. The effect is immediately noticeable: hair feels smoother, looks shinier and is easier to comb. But that feeling is not the result of healthy hair. It is the result of a layer of plastic applied over the hair.

With regular use, silicones build up. The hair shaft becomes covered in accumulated layers, which weighs the hair down and blocks the absorption of moisture and nutrients. Hair accustomed to silicones initially feels dry and rough after stopping, because it reveals the true condition of the hair shaft.

On the label you recognise silicones by words ending in -cone, -conol or -siloxane, such as Dimethicone, Cyclopentasiloxane or Amodimethicone. The natural alternative is plant-based oils such as avocado oil or argan oil, which nourish the hair without building up and are biodegradable.

3. Parabens: preservatives with a question mark

Parabens are synthetic preservatives that extend the shelf life of cosmetics. They have been used for decades and are effective, but they have been under scientific scrutiny for years due to their hormone-disrupting effects. Parabens mimic oestrogen in the body and are linked to disruptions of the endocrine system.

While the exact health risks are still being studied, more and more manufacturers and consumers are consciously choosing paraben-free products, especially with daily use. The cumulative exposure through multiple products simultaneously is a concern that is increasingly being taken seriously.

On the label you recognise parabens by names such as Methylparaben, Propylparaben, Butylparaben or Ethylparaben. The natural alternative is plant extracts with preserving properties, such as rosemary extract (Rosmarinus Officinalis Leaf Extract) or vitamin E (Tocopherol).

4. Mineral oils: petroleum derivatives that clog

Mineral oils are petroleum derivatives used in cosmetics for their smoothing and moisture-sealing properties. They are cheap, stable and create a soft feel on skin and hair. But they do not penetrate the hair shaft. They sit on top of it.

With regular use, mineral oils can clog the scalp and impede its natural breathing. For hair, they increase weight and coat the hair shaft without providing real nourishment. Over time, hair can look dull and heavy.

On the label you recognise mineral oils as Mineral Oil, Paraffinum Liquidum, Petrolatum or Cera Microcristallina. The natural alternative is plant-based oils such as jojoba oil (Simmondsia Chinensis Seed Oil) or shea butter (Butyrospermum Parkii Butter), which actually penetrate and nourish the hair shaft.

5. Microplastics: the problem you cannot see

Microplastics in cosmetics are small plastic particles added as a scrubbing agent, thickener or film-forming agent. They are so small that they are not filtered out by water treatment plants and enter surface water directly. Once in the environment, they never fully break down.

In shampoo, microplastics appear in two forms: as solid particles for a scrub effect and as liquid polymers that coat the hair. The latter is less well known but equally problematic. Recent research by the Plastic Soup Foundation confirms that nine out of ten bathroom products contain microplastics, including in liquid form.

On the label you recognise solid microplastics as Polyethylene or Polypropylene. Liquid polymers are listed as Acrylates Copolymer or Carbomer. The natural alternative is plant-based scrubbing agents such as sugar particles or finely ground seeds, and botanical film-forming agents based on plant mucilage.

Which sulphate-free, paraben-free shampoo bar suits your hair?

Nature Bar shampoo bars are free from all five ingredients mentioned above. They are formulated at a pH that matches the scalp, handmade in Amsterdam and plastic-free packaged. There is a specific bar for each hair type:

• Normal to oily hair: Shampoo Bar Balance & Deep Cleanse with basil, lemon and rosemary.
• Normal to fine hair: Shampoo Bar Strength & Volume with mandarin, ylang ylang and ginger.
• Normal to dry hair: Shampoo Bar Nourish & Repair with lavender, eucalyptus and rosemary.

Discover the full shampoo bar range for more information per hair type.