Mrs Ritchie's tip: Physical exfoliants scrub the skin to loosen dead skin cells. Chemical exfoliation use acids to 'lift' the skin cells and they do this uniformly and without risk of scratching the skin. Don't automatically think 'chemicals = harsher!' But do use acids judiciously as they disrupt your skin's barrier defence and overall skin function which will lead to premature ageing. We recommend acids to give dull sluggish skins a kick and unclog pores, reducing pore size and blemishes.