Does Salicylic Acid Thin the Skin ?

Salicylic acid is an excellent keratolytic and exfoliant. It should stimulate collagen and reduce pore size. Raffy Karamanoukian, Los Angeles

Salicylic acid is going primarily going to exfoliate the skin and diminish excess sebum that causes breakouts.  The exfoliation process will not thin skin in a negative way - it will mainly promote healthier skin and smaller pore size.  I would talk to your dermatologist before daily use of a product containing salicylic acid.  Sometimes more sensitive skin requires gradual increase to daily use.