LESSON 3 · Skin Science
Irritants to Avoid
Knowing what to skip matters as much as knowing what works. Fragrance, listed as parfum or fragrance, is the single most common cause of skincare reactions. It adds nothing beneficial and raises irritation risk for every skin type.
Denatured alcohol (alcohol denat) strips the skin barrier even though it makes products feel light and fast-absorbing. Essential oils like tea tree and lavender are common irritants sold as natural perks. Harsh scrub beads such as walnut shell powder create micro-tears in the skin; gentle chemical exfoliants like AHAs are kinder and more effective.