alpha-hydroxy acids (AHAs)
they are water soluble components, so they penetrate deeply into the epidermis, they are good for skin exfoliation and shred of dead cells, for collagen stimulation, and the normalization of the outer layer of the epidermis.
they are different types of ahas, the most common and used ones in cosmetic products are glycolic acid which comes from sugar, and lactic acid which comes from the milk.
- glycolic acid → sugar → exfoliates, evens the skintone, stimulates collagen production
- citric acid → citric fruits → spots/sun damaging
- mandelic acid → almonds → antibacterial, controls oiliness
- malic acid → pears, grapes → antioxidant
- tartaric acid → pears, grapes → antioxidant
- lactic acid → milk → skin maintaining, gently exfoliation
beta-hydroxy acids (BHAs)
they are lipid (oil) soluble, so they are likely more useful with oilier skin types. they are best used for exfoliation, taking care of break outs and for texturised or clogged pores.
there’s only one type of bhas, which is the salicylic acid which is taken from aspirin.