BHA means Beta-hydroxy acid. These acids can be dissolved in oils and are used in cosmetics for exfoliation.
BHAs can help to clean the skin, free its pores, and remove dead cells from above it. BHAs but also AHAs are a good choice if your skin is dull and has an uneven tone hyperpigmentated.
Though there are many acids that can be defined as BHAs by a chemist, it actually almost always salicylic acid, which is used in cosmetics. Citric, malic and tartaric acids belong to BHAs and AHAs, but act more as AHAs.
- Since BHAs are oil-soluble, they can go deeper into the skin and into the pores. So they will care well for oily skin and unclog pores, while AHAs are better for drier skin types.
- Concentration matters. The more BHA is in the product the more effective it will be. Too much however might cause irritation. We recommend starting with 1-2%.
- Acidity (or pH) is less important for BHAs than for AHAs to stay effective. If your skin is sensitive and redness prone, you might want to choose BHA-containing products with higher pH (4 or more) over ones with AHAs .
- Salicylic acid is a relative of aspirin. It has an an additional anti-inflammatory action on the skin.
- Salicylic acid has anti-bacterial properties. Besides cleaning the skin, it also protects it from microbe invasion.
- Same as for AHAs, we recommend using sunscreen after BHA application.
BHAs might cause irritation. We recommend starting with lower concentration products (under 2%) and using it every other day to avoid a skin reaction.