What to Never Put in Your Hair

Toronto weather demands a lot from us, and it demands even more from our hair. Between the harsh, dry, freezing winters and the heavy, humid summers, it is incredibly tempting to slather on any product that promises instant moisture, intense repair, or frizz control.

But what you put on your hair and scalp is just as important as what you leave out. Many conventional hair care products - and even popular DIY treatments - contain ingredients that actively strip moisture, clog follicles, and compromise your scalp health. Because your scalp is simply an extension of the skin on your face, treating it with the same rigorous standard you apply to your skincare routine is essential.

Here is the definitive guide to what you should absolutely never put in your hair.

1. The Moisture Strippers: Sulfates (SLS & SLES)

Sulfates, primarily Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES), are surfactants. They are the chemical detergents responsible for that rich, foamy lather in your shampoo.

While they excel at removing dirt and oil, they don't know when to stop. Sulfates aggressively strip away your scalp’s natural, necessary sebum.

• The Result: Dry, brittle hair, faded color treatments, and a dry, irritated scalp that overproduces oil to compensate.

• The Fix: Look for sulfate-free cleansers that use gentle, coconut-derived surfactants to clean the scalp without disrupting its natural moisture barrier.

2. The Fake Shine Impostors: Silicones

Silicones (like Dimethicone, Cyclomethicone, and Cyclopentasiloxane) are found in almost every mainstream conditioner, serum, and detangler. They work by coating the hair shaft in a microscopic waterproof seal, giving the immediate illusion of sleek, shiny, and frizz-free hair.

• The Result: Because silicones are essentially liquid plastics, they build up heavily over time. This impenetrable barrier prevents actual moisture (like water and nourishing oils) from penetrating the hair shaft, leading to strands that are suffocated, dehydrated, and prone to severe breakage from the inside out.

• The Fix: Swap silicones for lightweight, penetrating botanical oils like argan, jojoba, or squalane. If you have been using silicones, you will need a clarifying wash to remove the buildup.

3. The Follicle Cloggers: Mineral Oil and Petroleum

Often disguised under names like liquid paraffin or white petroleum, mineral oil is a cheap byproduct of the petroleum refining process. It is frequently used in hair masks and styling creams to lock in moisture and add weight to the hair.

• The Result: Mineral oil sits heavily on the surface of the scalp and hair. It clogs hair follicles - which can restrict healthy hair growth and lead to scalp acne - and leaves hair feeling stiff, weighed down, and lifeless.

• The Fix: Opt for formulas that utilize biocompatible hydrators that the skin and hair can easily absorb and utilize.

4. The Preservatives and Endocrine Disruptors: Parabens and Phthalates

Parabens (Methylparaben, Propylparaben, etc.) are preservatives used to extend a product’s shelf life by preventing mold and bacteria growth. Phthalates are chemicals used to increase the flexibility of styling products and make synthetic fragrances linger longer.

• The Result: Beyond just hair health, these ingredients pose systemic concerns. Research indicates that parabens can act as endocrine disruptors, meaning they can interfere with hormone production. Phthalates have been linked to similar reproductive and developmental issues.

• The Fix: Always read the labels. High-quality, professional-grade products will explicitly state that they are paraben-free and phthalate-free.

5. Harsh Chemical Treatments: Box Dyes and "Over-the-Counter" Relaxers

Professional hair color and smoothing treatments are formulated with careful chemical balances and applied by experts who monitor the integrity of your hair. At-home box dyes and relaxers are a completely different story.

• Box Dyes: Often contain high levels of Paraphenylenediamine (PPD) and uncontrolled volumes of ammonia or peroxide, which blast open the hair cuticle and cause permanent structural damage. They also frequently cause severe contact dermatitis on the scalp.
• At-Home Relaxers: Over-the-counter "no-lye" relaxers (containing guanidine hydroxide) can permanently weaken the hair shaft and cause severe chemical burns to the scalp if not applied with absolute precision.

6. Kitchen "Hacks" to Avoid: Baking Soda and Lemon Juice

The internet is full of DIY hair care remedies, but the kitchen is not a laboratory.

• Baking Soda: With a highly alkaline pH of 9, scrubbing your scalp with baking soda aggressively disrupts the natural acid mantle of your scalp (which sits around a pH of 4.5 to 5.5). This causes severe cuticle damage and extreme frizz.

• Lemon Juice: Highly acidic and photosensitive. Applying lemon juice to your hair and going out into the sun causes a chemical reaction that destroys the hair's melanin and breaks down its structural proteins, leaving it fried and brittle.

The Deco De Mode Toronto Verdict: Scalp Health is Skin Health

Beautiful hair does not start at the ends; it starts at the root. If the scalp is clogged with mineral oil, irritated by sulfates, or suffocated by silicones, the hair it produces will inherently be weaker, thinner, and duller.

Here at Deco De Mode Toronto, we approach aesthetic wellness holistically. Upgrading your hair care routine to exclude these damaging ingredients is one of the easiest and most effective ways to protect the integrity of your hair and the health of your scalp. Invest in high-quality, scientifically backed formulations, and your hair will thank you for it.

‍