Also known as: BHA, beta hydroxy acid
What Is Salicylic Acid (BHA)?
Salicylic acid is a beta hydroxy acid, originally derived from willow bark and now usually made synthetically. Its defining feature is that it is oil-soluble. While water-soluble acids like glycolic acid work mostly on the surface, salicylic acid can move through sebum and into the pore lining, where it loosens the mix of dead cells and oil that forms blackheads and whiteheads.
That makes it particularly useful for breakouts, congested, visible pores and oily skin. Salicylic acid belongs to the same chemical family as aspirin, and it has a mild anti-inflammatory effect, which helps take the edge off red, swollen spots. In the US it is an approved over-the-counter acne active, typically at concentrations from 0.5 to 2 percent.
You will find it in cleansers, toners, pads, serums, spot treatments and peels. Leave-on formats give it more time to work, while rinse-off cleansers are gentler and good for beginners. For a side-by-side look at how it differs from AHAs, see AHA vs BHA.
Salicylic Acid (BHA) Benefits for Skin
- Helps clear blackheads and whiteheads by working inside the pore.
- Helps reduce the number of breakouts with regular use.
- Calms the look of red, inflamed blemishes.
- Helps pores look smaller and smoother.
- Softens rough texture and helps control the look of shine.
How to Use Salicylic Acid (BHA)
Start with a leave-on BHA two or three evenings a week on clean, dry skin, then increase to daily use if your skin stays comfortable. Follow with a lightweight moisturizer — oily skin still needs hydration (does oily skin need moisturizer?). Apply sunscreen every morning, since exfoliated skin is more vulnerable to sun damage.
If you also use a retinoid, alternate nights at first rather than layering both in one routine; this guide to retinol and salicylic acid explains how to combine them. Avoid stacking salicylic acid with other acids or scrubs in the same session.
Side Effects & Precautions
Dryness, flaking, tightness and stinging are the most common side effects, especially when starting or overusing it. Some people see a short period of extra breakouts as clogged pores clear; learn to tell the difference in skin purging vs breakout. If irritation persists, cut back the frequency.
People with an aspirin allergy should check with a doctor before using salicylic acid. If you are pregnant or breastfeeding, ask your doctor before using leave-on salicylic acid products or peels.
Use caution when combining
- Retinoids on the same night, at least at first.
- Other strong acids or physical scrubs.
- Aspirin allergy — check with a doctor first.
Frequently Asked Questions
Can I use salicylic acid every day?
Many people with oily skin can, once their skin has adjusted. Start a few times a week and increase gradually. If you notice tightness, flaking or stinging, scale back.
Is salicylic acid good for dry skin?
It can be used on dry skin for occasional congestion, but it is drying, so use it sparingly and pair it with a rich moisturizer. Lactic acid or PHAs are often more comfortable exfoliants for dry skin.
Should I use salicylic acid in the morning or at night?
Either works. Many people prefer the evening so it does not interfere with morning products, but if you use a retinoid at night, a morning BHA followed by sunscreen is a sensible way to separate them.