Salicylic Acid vs. Glycolic Acid — Which Works Better for Acne?

Acne and skincare — the role of exfoliating acids

Acne vulgaris (acne vulgaris) is a multifactorial condition whose development is driven by several key factors: excess sebum production, abnormal keratinisation, colonisation by Cutibacterium acnes, and inflammation. This is precisely why effective care for acne-prone skin has to work on multiple fronts. Two ingredients that appear again and again in anti-acne formulations are salicylic acid (BHA) and glycolic acid (AHA). Although both exfoliate the skin, their mechanisms and effectiveness profiles are different.

Before we get to the comparison, an important caveat: the information below is for educational purposes only. Acne can have different underlying causes, and for severe or inflammatory breakouts you should consult a dermatologist. This is not medical advice.

Salicylic acid — the pore specialist

Salicylic acid belongs to the beta-hydroxy acid (BHA) group. Its most important trait is lipophilicity — its solubility in oils. This property lets it penetrate the sebum that fills the pores and act directly where blackheads and inflammatory lesions form.

How salicylic acid works in acne:

• Keratolytic: loosens and removes clusters of dead cells inside the pore, preventing it from becoming clogged
• Comedolytic: reduces existing open and closed comedones
• Anti-inflammatory: as a derivative of salicylic acid, it inhibits the synthesis of prostaglandins — mediators of inflammation
• Antibacterial: creates an unfavourable environment for C. acnes, although it is not a primary antibacterial agent

In line with SCCS guidelines and EU Regulation 1223/2009, salicylic acid is permitted in cosmetics at concentrations up to 2%. Products with higher concentrations (3–30%) are used exclusively in dermatology or aesthetic clinics. Check for its presence in products in our INCI ingredient encyclopaedia.

Glycolic acid — exfoliation and evening out the skin

Glycolic acid is an alpha-hydroxy acid (AHA) with the smallest molecule in its group, which gives it relatively deep penetration into the epidermis. However, it is hydrophilic — water-soluble — meaning it does not penetrate the sebaceous glands the way salicylic acid does.

In the context of acne, it works by:

• Speeding up epidermal renewal: faster shedding of dead cells reduces the risk of clogged pores
• Reducing post-acne discolouration: it stimulates cell turnover, lightening post-inflammatory hyperpigmentation
• Stimulating collagen: at higher concentrations it supports skin regeneration and smooths scars

The European Commission limits AHA concentrations in consumer products to 10% (at pH ≥ 3.5). Glycolic acid has no direct comedolytic or anti-inflammatory action — its role in acne is primarily secondary (removing the after-effects) and preventive (helping to keep pores from clogging).

You'll find products containing glycolic acid in the spot treatments category.

Head-to-head: which acid for acne?

• Blackheads and clogged pores: Salicylic acid — clearly better (lipophilicity, keratolytic and comedolytic action)
• Inflammatory acne (pustules, papules): Salicylic acid — the edge here thanks to its anti-inflammatory action
• Post-acne discolouration: Glycolic acid — more effective at lightening hyperpigmentation
• Acne scars: Glycolic acid (at higher concentrations) or a combination of both
• Sensitive, acne-prone skin: Salicylic acid at low concentrations (0.5–1%) — less irritating than high-strength AHAs

Can you combine both acids?

Yes, combining them is possible and commonly done, but it requires caution. The most frequently used strategy is:

1. Morning: a product with salicylic acid (e.g. a toner or cleansing gel at 0.5–2%)
2. Evening: a product with glycolic acid (e.g. a toner or serum) a few times a week
3. Alternatively: products formulated with both acids together at lower concentrations

Never combine both acids in the same application with retinol or strong formulas — the risk of excessive irritation and damage to the skin barrier is too high.

What to look for when choosing a product?

When reviewing the INCI list, check:

• Whether the active acid appears in the first half of the ingredient list
• The concentration — often stated directly by the manufacturer or estimable from its position on the INCI list
• The formula's pH — acids only work at a suitably low pH (2.5–4 for AHAs, up to 4 for salicylic acid)
• Additional soothing ingredients (panthenol, allantoin) — these reduce the risk of irritation

Check the ingredients in your cosmetics →