When it comes to glowing, healthy-looking skin, exfoliation is key.
But forget harsh scrubs-the most effective exfoliants today are chemical acids, particularly AHAs (alpha hydroxy acids) and BHAs (beta hydroxy acids).
You’ll find these ingredients in everything from cleansers to serums and professional peels- but what exactly do they do, and which one should you choose?
Let’s break it down.
What Are AHAs and BHAs?
Both AHAs and BHAs are chemical exfoliants that help to remove dead skin cells from the surface of the skin.
Unlike physical exfoliators (which use gritty particles to manually scrub the skin), these acids dissolve the bonds that hold dead cells together- revealing a fresher, smoother complexion underneath.
- AHAs are water-soluble, meaning they work on the skin’s surface.
- BHAs are oil-soluble, so they can penetrate deeper into the pores to help clear congestion and excess sebum.
Alpha Hydroxy Acids (AHAs)
AHAs are derived mainly from fruits, milk, and sugar cane.
They’re best suited to dry, dull, or sun-damaged skin because they improve texture and brightness while helping with fine lines and pigmentation.
Common Types of AHAs
- Glycolic Acid
- Derived from sugar cane
- The smallest AHA molecule, meaning it penetrates deeply
- Excellent for improving skin tone, texture, and collagen stimulation
- Derived from sugar cane
- Lactic Acid
- Sourced from milk or fermented sugar
- Gentler than glycolic acid
- Ideal for sensitive skin or first-time acid users
- Helps hydrate while exfoliating
- Sourced from milk or fermented sugar
- Mandelic Acid
- Derived from bitter almonds
- Larger molecule = slower penetration
- Great for sensitive or acne-prone skin
- Known to refine pores and even out pigmentation
- Derived from bitter almonds
- Citric Acid
- Found in citrus fruits
- Often used to adjust pH or add antioxidant benefits
- Helps brighten dull skin
- Found in citrus fruits
- Malic Acid
- From apples and pears
- Often used in combination with other AHAs for a smoother finish
- From apples and pears
Beta Hydroxy Acids (BHAs)
BHAs work below the surface of the skin, making them perfect for oily, acne-prone, or congested skin types.
Because they are oil-soluble, they can penetrate the pores to break down oil and debris, reducing blackheads and blemishes.
Common Types of BHAs
- Salicylic Acid
- The most well-known BHA (derived from willow bark)
- Unclogs pores and reduces oiliness
- Has anti-inflammatory and antibacterial properties
- Helps calm redness and treat acne
- The most well-known BHA (derived from willow bark)
- Betaine Salicylate
- A gentler, plant-derived alternative to salicylic acid
- Provides mild exfoliation with less irritation
- Suitable for sensitive skin
- A gentler, plant-derived alternative to salicylic acid
Can You Use AHAs and BHAs Together?
Yes-when used correctly! Combining both can offer a more comprehensive exfoliation:
- AHAs work on the surface, smoothing and brightening.
- BHAs work deeper, clearing pores and reducing breakouts.
However, over-exfoliation can cause sensitivity. If you’re new to acids, start slowly- alternating days or using one at a time-and always use broad-spectrum SPF 50 during the day, as exfoliating acids increase sun sensitivity.
The Bottom Line
- AHAs = Surface exfoliation → brighter, smoother, hydrated skin.
- BHAs = Deep exfoliation → clearer pores, reduced breakouts, less oil.
- Used properly, they can transform the skin’s texture, radiance, and overall health.
