If you’re dealing with acne, clogged pores, dull skin, or breakouts, you’ve probably heard about AHA and BHA. But which one should you use? Each has its strengths. Use this guide to figure out which acid fits your skin goals — or how to combine them safely for better results.
What are AHAs and BHAs?
Term |
Details |
Common Types |
How It Works |
AHA (Alpha-Hydroxy Acid)
|
Water-soluble acids derived from sugars, milk, or fruit. |
Glycolic, lactic, mandelic, tartaric acids |
Exfoliate the skin’s surface by loosening the “glue” between dead skin cells; improve texture, radiance, and moisture retention. |
BHA (Beta-Hydroxy Acid)
|
Oil-soluble acids |
Primarily salicylic acid |
Penetrates into pores to dissolve oil and debris; helps with blackheads, clogged pores, oily or acne-prone skin. Also has anti-inflammatory properties. |
How They Differ: What Suits Your Skin Best
Factor |
AHA Strengths
|
BHA Strengths
|
Best for Skin Type
|
Dry, sun-damaged, dull skin, or those wanting overall brightening. |
Oily, acne-prone, congested skin; those with blackheads and enlarged pores. |
Depth
|
Surface exfoliation; weaker AHAs (like lactic) are gentler. |
Deeper penetration into pores, oil channels. |
Irritation Potential
|
Can cause sensitivity, especially with strong acids or low pH. |
Also can irritate, but often more tolerated by oily skin; overuse can still cause dryness or peeling. |
Sun Sensitivity
|
Increases sensitivity to UV; sunscreen essential. |
Same risk; must use SPF daily. |
How to Choose & Use Them Safely
Start slow |
Begin with a lower concentration (e.g. 5-10% glycolic or lactic for AHAs; 0.5-2% salicylic for BHAs), 2-3 times per week. Watch for irritation. |
Patch test
|
Try on a small area (jawline or side of face) for a few nights. |
Time of use |
Often applied at night. If you use a BHA, you might start with that and see how your skin tolerates it. |
Layering & compatibility |
-
AHAs + BHA: possible, but avoid stacking high concentrations or using both every night until skin builds tolerance.
-
Avoid combination with other strong actives (e.g. retinol, vitamin C, benzoyl peroxide) initially.
|
Sun protection |
Both acids thin the outer barriers momentarily. Daily SPF 30+ is non-negotiable. |
When to Use Which (Or Both)
-
If your main concern is dull skin or fine lines → go with an AHA.
-
If you're fighting clogged pores, blackheads, oily sheen → BHA is likely better.
-
If multiple concerns → alternate use (e.g., BHA one night, AHA the next) or use a product that combines low levels of each (once skin is tolerant).
Side Effects & What to Watch For
- Mild tingling or flushing when first applied is normal.
- Over-exfoliation signs: persistent redness, peeling, stinging. If these appear, back off to every other night, then gradually increase.
- Always moisturize well.
- Always avoid sun exposure without protection.
FAQ
Can I use both AHA and BHA together in one routine? |
Yes — but only if your skin tolerates it. It’s better to start on alternate nights or use one in the morning, one at night. |
How soon will I see results?
|
Some improvements (brightness, texture) might show up in a week or two. Full effects (less breakouts, fewer blackheads) often take 4–6 weeks. |
Will acids thin my skin?
|
They can temporarily encourage more shedding of the outer layer, but when formulated well and used properly, they help strengthen skin over time. Consistent moisturizing and protection are essential. |
Will acids thin my skin?
They can temporarily encourage more shedding of the outer layer, but when formulated well and used properly, they help strengthen skin over time. Consistent moisturizing and protection are essential.
Key Takeaways
- AHA = surface exfoliation, brightening, smoothing
- BHA = deeper pore cleansing, ideal for oil and acne
- Go gentle, build up slowly, moisturize, protect from the sun
- There’s no one “best” acid; it depends on your skin’s needs