AHA vs BHA vs PHA: Which Exfoliating Acid Is Right for Your Skin?
Posted by Skinsider Team on 17th Feb 2026
Exfoliating acids help remove dead skin cells, smooth texture, and brighten your complexion. They differ in how deeply they penetrate the skin and which skin concerns they target. Choosing the right acid can make a big difference in your routine.
What is a AHA?
Alpha Hydroxy Acids (AHAs) are water-soluble and work mainly on the skin’s surface. They’re great for dry, dull, or uneven skin, helping to gently dissolve dead cells and reveal smoother, more radiant skin underneath. AHAs like glycolic or lactic acid can also help with pigmentation and fine lines. A standout product is the COSRX AHA 7 Whitehead Power Liquid, which works really well to reduce whiteheads, smooth texture, and give skin a healthy glow.
When to use: AHAs are best used in the evening because they can increase sun sensitivity. Always follow up with sunscreen in the morning.
Can you combine with other acids? It’s possible, but with caution. Combining AHA with BHA in the same routine can be done if your skin tolerates it, but it’s better to alternate days to prevent irritation.
What is BHA?
Beta Hydroxy Acid (BHA), most commonly salicylic acid, is oil-soluble and can penetrate deep into pores. This makes it ideal for oily or acne-prone skin. BHA helps unclog pores, reduce blackheads, and calm inflammation, tackling breakouts at their source. A product I like for this is NINELESS A-Control Heartleaf & BHA Cleanser 120ml, which gently exfoliates while controlling oil and soothing irritated areas.
When to use: BHA can be used in the morning or evening, but it’s often preferred in the evening to give it time to work overnight.
Can you combine with other acids? BHAs can be combined with PHAs safely or used alongside AHAs on alternate days. Layering too many strong acids at once can cause dryness or irritation.
What is PHA?
Polyhydroxy Acids (PHAs) are the gentlest option. They work like AHAs but penetrate more slowly, making them ideal for sensitive or reactive skin. PHAs also attract moisture, providing gentle hydration while refining texture. A great example is AXIS-Y PHA Resurfacing Glow Peel 50ml, which smooths the skin surface, boosts radiance, and is very gentle even for sensitive skin.
When to use: PHAs are flexible — morning or evening, depending on your other products. They’re safe to combine with most acids and act as a gentle daily exfoliant for sensitive skin.
How to Choose The Right Acid?
If your skin is dry or dull, AHA is ideal for evening use. For oily, acne-prone skin, BHA works best, usually at night. PHAs are perfect for sensitive skin and can even be used daily. Many people choose to alternate acids, for example, AHA one evening, BHA the next to maximize benefits without over-exfoliating. Always monitor your skin, start slowly, and pair acids with sunscreen to protect your skin barrier.
