You know what cosmetic doesn't get enough attention? Toothpaste! I was just writing up something on why toothpaste is not a good spot treatment for acne and thought, now there's one area of cosmetic science that is not discussed much.

Toothpaste contains surfactants which create foam and act as cleansing agents. Thats why they are formulated into body washes or shampoo, where they are intended to be rinsed off. Prolonged contact with skin causes disruption of the lipid barrier and irritation. #cosmeticchemist

Some toothpastes used to contain triclosan as an antimicrobial to prevent gingivitis. It could have reduced the effects of C. acnes (formerly called P. acnes) in exacerbating acne. This bacteria breaks down sebum trapped in pores into free fatty acids causing inflammation.