Comparison

Glycolic Acid vs Salicylic Acid (AHA vs BHA)

The two most popular chemical exfoliants. One works on the surface, the other works inside pores. Which do you need?

Last reviewed: March 2026 · Our methodology

Overview

Glycolic acid (an AHA) and salicylic acid (a BHA) are both chemical exfoliants, but they work differently. Glycolic acid is water-soluble and exfoliates the skin surface. Salicylic acid is oil-soluble and penetrates into pores. This fundamental difference determines which is better for your concern.

	Glycolic Acid (AHA)	Salicylic Acid (BHA)
Best for	Texture, fine lines, pigmentation, dullness	Blackheads, oily skin, pore congestion, acne
Evidence	Strong	Strong
How it works	Dissolves bonds between dead surface cells (water-soluble)	Penetrates into pores and dissolves sebum plugs (oil-soluble)
Irritation risk	Moderate-high (increases with concentration)	Low-moderate (generally better tolerated)
Photosensitivity	Yes — increases UV sensitivity. SPF essential.	Minimal — does not significantly increase photosensitivity
Best skin types	Normal, dry, mature, sun-damaged	Oily, acne-prone, combination
Concentration (OTC)	5–10% (home use); up to 30–70% (professional peels)	0.5–2% (most effective at 2%)
Anti-ageing	Yes — stimulates collagen at higher concentrations	Minimal direct anti-ageing benefit

Recommended Choice by Scenario

If you have blackheads and oily skin

Salicylic acid 2% is the clear choice. As the only oil-soluble exfoliant, it can penetrate into pores to dissolve the sebum plugs that cause blackheads. Glycolic acid works on the surface and cannot do this effectively.

If you want smoother texture and brighter skin

Glycolic acid is stronger at surface exfoliation and has better evidence for texture improvement, fine line reduction, and pigmentation. Start with 5% and build to 8–10% as tolerated.

If you have acne and ageing concerns

Consider using both — salicylic acid for pore clearance and glycolic acid for surface renewal. Use them on alternate nights rather than layering in the same routine to minimise irritation.

If you have sensitive skin

Salicylic acid at 0.5–2% is generally better tolerated than glycolic acid. If you want an AHA that is gentler, consider mandelic acid (the largest AHA molecule, slowest penetration) rather than glycolic.

Can you use both?

Yes, but not in the same application. Use one in the morning and one at night, or alternate nights. Monitor for signs of over-exfoliation: persistent tightness, stinging with products that previously did not sting, or unusual dryness.

Frequently Asked Questions

Should I use glycolic acid or salicylic acid for acne? +

Salicylic acid is generally preferred for acne because it is oil-soluble and penetrates into pores to clear congestion and blackheads. Glycolic acid works on the skin surface and is better suited for texture, pigmentation, and anti-ageing concerns.

Can I use glycolic acid and salicylic acid together? +

Using both in the same routine increases irritation risk significantly. If you want to use both, alternate them on different nights or use salicylic acid as a cleanser and glycolic acid as a leave-on treatment on separate days.

Which acid is better for sensitive skin? +

Neither is ideal for very sensitive skin. If you must choose, salicylic acid at low concentrations (0.5 to 1 percent) tends to be less irritating than glycolic acid because it has anti-inflammatory properties. Mandelic acid is the gentlest AHA alternative.

Disclaimer

This comparison is educational and simplified. Individual responses vary. Consult a healthcare provider for personalised advice.