Actives glossary
Salicylic acid
Oil-soluble, which is the single property that decides where it is useful.
- INCI name
- Salicylic Acid
- Also called
- BHA, beta hydroxy acid
- Family
- Acid
- Range seen on labels
- 0.5% to 2% over the counter
- Sits well with
- niacinamide, ceramides
- Needs care with
- retinol, retinaldehyde, glycolic-acid
Salicylic acid dissolves in oil. That is the property worth remembering, because it lets the acid reach into a pore lined with sebum in a way a water-soluble acid does not. Everything else about the category follows from it.
The 2% ceiling
Over-the-counter products in the United States top out at 2% for a leave-on. A product claiming a higher figure is either a rinse-off, a professional product, or misdescribed. The percentage is also less important than contact time: a 2% cleanser that spends thirty seconds on the face is a different exposure from a 0.5% leave-on.
Where it does not help
Dryness, flaking and a tight feeling after using it are not signs it is working. They are signs of over-exposure, and the usual fix is less often rather than a lower percentage.