AHAs vs. BHAs: What’s the Difference and When Should You Use Them?

AHAs vs. BHAs: What’s the Difference

What Are AHAs and BHAs?
AHA (Alpha Hydroxy Acid) and BHA (Beta Hydroxy Acid) are chemical exfoliants, meaning they help shed dead skin cells without the need for physical scrubbing. Unlike gritty scrubs that, with over use, can cause microtears in the skin, AHAs and BHAs work by dissolving the "glue" that holds dull, dead skin on the surface.
But AHAs and BHAs are not the same.

• AHAs are water-soluble.
• BHAs are oil-soluble.

This one factor determines how they interact with the skin and what skin concerns they’re best suited for.

I found the best way to remember is to think A-Above the skin, and B-Below the skin!

Alpha Hydroxy Acids (AHAs):

AHAs, like glycolic, lactic and mandelic acids, work on the surface layer of the skin. They help to gently exfoliate the outer layer of dead skin, fade hyperpigmentation and sun damage and boost collagen production over time. You'll also find improvement in skin texture and tone. AHAs help hydration by improving the skin’s ability to retain moisture.

AHAs are best for:

• Dry, dull, or flaky skin
• Uneven tone or texture
• Sun-damaged or aging skin

When to use:
2–3 times a week, at night. AHAs increase sun sensitivity, so SPF is non-negotiable during the day.

Beta Hydroxy Acids (BHAs):

BHAs, primarily salicylic acid, are a pore-penetrating powerhouse. BHAs can dive deep into pores, clearing out excess sebum (oil) and dead skin that cause breakouts and blackheads.
They also have anti-inflammatory and antibacterial properties, which is a major bonus for acne-prone skin.

BHAs are best for:

• Oily or combination skin
• Acne, blackheads, or whiteheads
• Congested pores
• Skin prone to breakouts or inflammation

When to use:
1–3 times a week, depending on skin tolerance. Can often be used as a spot treatment or full-face product in cleansers, serum, toners, or masks.


Can You Use AHAs and BHAs Together?

Yes—but with caution. Combining AHAs and BHAs can be highly effective for those dealing with multiple concerns (like acne and texture or hyperpigmentation), but it’s also easy to overdo it. Over-exfoliation can lead to redness, sensitivity, and even breakouts. We often recommend layering, alternating, or looking for a formula that combines both in a balanced concentrations. ( Vivier AHA/BHA is a personal favourite)
Always be sure to follow with hydration and moisturizer to soothe your skin...and never skip your SPF in the morning!


Professional Insight: How We Recommend Them

• Dry, aging, or sensitive skin?  often start with a low-percentage lactic acid or mandelic acid AHA 2–3 times per week to brighten and smooth. (Vivier Illuminating Enzymatic Peel)

• Acne-prone, oily, or clogged skin? typically recommend a salicylic acid BHA 2-4% cleanser or evening treatment cream ( Vivier Medicated Wash)

• Post-acne marks and uneven tone? A blend of AHA and BHA (or alternating use) can address both surface pigmentation and pore congestion. Another great option is in clinic chemical peels.( Vivier Peel and Jessner Peel)

Final Thoughts

AHAs and BHAs are not one-size-fits-all, but when used correctly, they can elevate any skincare routine. Always start slow, pay attention to your skin's response. Speak with a skincare specialist about your skin concerns and use the right products for your skin type and condition.... and don’t underestimate the importance of sun protection when using any exfoliating acids!
Your skin will thank you for it.