Some ingredients in mainstream skincare aren't dangerous in isolation. They're just not doing anything useful — and in some cases, they're quietly working against you. Here's a short list worth knowing.
Sodium lauryl sulfate (SLS). Common in cleansers for the foam it produces. Foam doesn't clean better — it's a psychological cue. SLS strips the skin barrier more aggressively than necessary, leaving skin more susceptible to irritation and moisture loss. Sodium laureth sulfate (SLES) is milder; other surfactants like cocamidopropyl betaine are milder still.
Denatured alcohol (alcohol denat). Shows up in toners and "oil-free" products to create that tightening, mattifying effect. Short-term it feels like it's doing something. Long-term it disrupts the skin barrier, triggers rebound oil production, and contributes to sensitization.
Parfum / Fragrance. Already covered in an earlier post, but worth repeating: fragrance is the most common irritant in skincare products and one of the hardest to trace. If a product lists "fragrance" as an ingredient, you have no idea what's actually in it — it's a catch-all term that can cover hundreds of individual chemicals.
PEG compounds. Common emulsifiers and penetration enhancers. Not acutely dangerous, but they can increase the absorption of other ingredients — which matters if those other ingredients are things you'd rather keep on the surface.
Mineral oil and petrolatum (in low-grade formulations). Not inherently harmful, but in low-quality formulations can clog pores and sit on the surface without contributing anything to barrier repair or hydration.
The goal isn't a paranoid label audit every time you shop. The goal is knowing what to deprioritize when you're comparing two products and one has a cleaner formulation than the other. That knowledge compounds over time.
