BHA / Salicylic acid

BHA / Salicylic acid (살리실산) is a fat-soluble beta-hydroxy acid peel that penetrates deep into the pores and dissolves impurities from the inside out.

INCI name	Salicylic Acid
category	Exfoliation, pores
Suitable for	Oily skin, combination skin, blemished skin
concentration	0.5% - 2% (in Germany, available without a prescription up to 0.5%)

Characteristic	Evaluation
Pore ​​cleansing	★★★★★
Anti-acne effect	★★★★★
Anti-inflammatory	★★★★☆
Skin compatibility	★★★☆☆
Scientific evidence	★★★★★

BHA is the only exfoliating agent that, due to its oil solubility, can penetrate directly into clogged pores and cleanse them from within. For oily and blemished skin, salicylic acid is therefore often more effective than water-soluble AHA acids.

What is BHA / salicylic acid?

Beta-hydroxy acid, or BHA for short, is a chemical exfoliating agent originally derived from willow bark. The best-known and only BHA used in cosmetics is salicylic acid. Unlike alpha-hydroxy acids (AHAs) such as glycolic acid or lactic acid, BHA is fat-soluble – a property that makes a crucial difference in its mode of action.

This fat solubility allows salicylic acid to penetrate the sebum in the pores and dissolve keratinization and deposits. While AHA acids primarily act on the skin's surface, BHA can penetrate deep into the pores and cleanse them from within. The concentration of salicylic acid in cosmetics varies between 0.5% and 2%, with a maximum of 0.5% permitted without a prescription in Germany.

In the K-beauty world, BHA has established itself as an indispensable ingredient for treating enlarged pores, blackheads, and blemishes. Korean formulations often rely on lower concentrations, which are applied regularly—an approach that results in less skin irritation while providing continuous effectiveness.

This is how BHA / salicylic acid works on your skin

Deep pore cleansing

The most important property of BHA is its ability to unclog pores. A study by Zhai & Maibach (2004) in the Journal of Cosmetic Dermatology showed that salicylic acid significantly reduces the number of blackheads by dissolving keratin and sebum in the pores. This keratolytic effect ensures that clogged pores are cleared and fewer new blemishes can form.

Anti-inflammatory properties

Salicylic acid belongs to the salicylate family and therefore possesses natural anti-inflammatory properties. Kligman & Mills (1972) documented in their seminal research that BHA not only exfoliates but also soothes active inflammation in the form of pimples. This dual action makes salicylic acid particularly valuable for blemished skin.

Regulation of sebum production

Regular use of BHA can normalize sebum production. A 12-week study by Draelos et al. (2006) showed that 2% salicylic acid treatments led to a measurable reduction in surface sebum without excessively drying the skin.

Improvement of skin texture

BHA smooths the skin's surface by continuously removing dead skin cells. This effect is particularly noticeable on skin with large pores, as the pores appear refined through cleansing.

Lightening of pigment spots

Although BHA is not as effective against pigmentation as AHA, it can still help lighten acne scars by accelerating cell renewal. The combination of exfoliation and anti-inflammatory properties also prevents the formation of new pigment spots caused by inflammation.

Who is BHA / salicylic acid suitable for?

skin type	fitness	Recommendation
Oily skin	★★★★★	Ideal - suitable for daily use
Combination skin	★★★★★	Apply to T-zone only
Impure skin	★★★★★	First choice for acne
Normal skin	★★★☆☆	2-3 times per week
Dry skin	★★☆☆☆	Use only sparingly.
Sensitive skin	★★☆☆☆	Low concentration, rare

Integration into your K-Beauty routine

Application time: BHA should only be used in the evening, as it makes the skin more sensitive to light. The initial phase should begin with 2-3 applications per week before switching to daily use.

Routine step: In the K-beauty routine, BHA comes after cleansing and pH-balancing toner, but before essences and serums. A waiting period of 15-20 minutes after BHA application optimizes its effects before the next skincare steps are followed.

Combination rules: BHA should never be used simultaneously with AHAs, retinol, or vitamin C. These active ingredients can be incorporated into your routine on different days. It is especially important to use sunscreen the following morning, as BHA increases UV sensitivity.

Supportive care: After BHA application, soothing ingredients such as niacinamide, centella asiatica or hyaluronic acid are ideal to minimize possible irritations and strengthen the skin barrier.

The best K-Beauty products with BHA / Salicylic acid

SOME BY MI 30 Days Miracle Clear Spot Patch (€5.50)
These innovative spot patches contain salicylic acid for targeted overnight blemish treatment. The hydrocolloid technology also draws impurities from the skin and accelerates healing.

Medicube Zero Foam Cleanser (€16.50)
A gentle cleansing foam with BHA that can be used daily. The low salicylic acid concentration gently cleanses the pores without drying out the skin – ideal for those new to BHA skincare.

Isntree Hyper Acid4 30 Serum (€3.99)
A highly concentrated acid serum that combines BHA with other active acids. Particularly suitable for experienced users seeking intensive pore treatment.

VT Cosmetics Cica Reti-A Essence 0.1 (€35.50)
An advanced essence that combines BHA with retinol and soothing centella. The formula is specifically designed to treat acne scars and stubborn blemishes.

BHA vs. other exfoliating agents

Active ingredient	solubility	Main effect	Best use
BHA / Salicylic acid	Fat-soluble	Pore ​​cleansing, anti-acne	Oily, blemished skin
AHA / Glycolic acid	Water soluble	Surface peeling, anti-aging	Dry, mature skin
PHA / Lactobionic acid	Water soluble	Gentle exfoliation, moisture	Sensitive skin
Retinol	Fat-soluble	Cell renewal, anti-aging	Mature skin, pigmentation

Myths and facts about BHA

Myth: "BHA makes the skin permanently thinner and more sensitive."
Fact: BHA only removes dead skin cells and stimulates natural cell renewal. When used correctly, it does not cause permanent damage to the skin, but rather makes it healthier and more resilient.

Myth: "Higher BHA concentration always means better results."
Fact: Lower concentrations (0.5-1%) used regularly are often more effective and better tolerated than high concentrations used only occasionally. The Korean philosophy of gentle, continuous treatment shows better long-term results.

Myth: "BHA can be used simultaneously with all other active ingredients."
Fact: BHA should not be combined with other highly active ingredients such as AHA, retinol, or highly concentrated vitamin C, as this can lead to over-exfoliation and skin damage.

Frequently asked questions about BHA / salicylic acid

How quickly does BHA take effect?
Initial improvements are usually visible after 2-4 weeks. Significant results regarding pores and blemishes appear after 6-8 weeks of regular use.

Can I use BHA in the morning?
BHA should only be used in the evening, as it increases UV sensitivity. The next day, sunscreen with at least SPF 30 is essential.

What happens if you overdose on BHA?
Overuse can lead to dryness, redness, and increased sensitivity. At the first signs of these symptoms, reduce application and use soothing skincare.

Is BHA also suitable for anti-aging?
Yes, BHA improves skin texture and can soften fine lines. However, for primary anti-aging goals, AHAs or retinol are usually more effective.

Can I use BHA during pregnancy?
Low concentrations up to 0.5% are considered harmless. At higher concentrations, a doctor should be consulted.

Why does BHA burn my skin?
A slight tingling sensation is normal, but a strong burning sensation indicates hypersensitivity. The concentration should be reduced or the application paused.

Can I combine BHA with niacinamide?
Yes, niacinamide can even be used after BHA to reduce irritation and strengthen the skin barrier.

How long can I use BHA?
BHA can be used long-term. After the first few months, the frequency can often be reduced as the skin improves.