You've seen them on ingredient lists, heard them mentioned in skincare videos, and maybe even bought a product containing them without fully understanding what they do. AHA and BHA are two of the most powerful — and most misunderstood — ingredients in skincare. Here's everything you need to know.
What Is Exfoliation, Really?
Your skin naturally sheds dead cells every 28-40 days. But with age, stress, pollution, and sun damage, this process slows down. Dead cells accumulate on the surface, leading to dullness, clogged pores, uneven texture, and a complexion that looks tired rather than radiant.
Exfoliation speeds up this renewal process — removing dead cells to reveal the fresher, brighter skin underneath. Chemical exfoliants like AHA and BHA do this more gently and effectively than physical scrubs, which can cause micro-tears in the skin.
AHA: The Surface Brightener
AHA stands for Alpha Hydroxy Acid. These are water-soluble acids derived from natural sources — fruit, milk, sugar — that work on the surface of the skin.
What AHAs do:
- Dissolve the bonds between dead skin cells, allowing them to shed more easily
- Brighten dull, uneven skin tone
- Improve the appearance of fine lines and texture
- Boost hydration by improving the skin's ability to retain moisture
- Fade hyperpigmentation and post-acne marks over time
Best for: Dry, dull, or aging skin. Normal to dry skin types. Those targeting uneven tone or texture.
Common AHAs include glycolic acid (most potent), lactic acid (gentler, more hydrating), and mandelic acid (gentlest, great for sensitive skin).
BHA: The Pore Purifier
BHA stands for Beta Hydroxy Acid. The most common BHA is salicylic acid — an oil-soluble acid that can penetrate deep into the pore.
What BHAs do:
- Cut through sebum and dissolve the buildup inside pores
- Reduce blackheads and whiteheads
- Calm inflammation and redness
- Prevent and treat breakouts
- Refine pore appearance over time
Best for: Oily, acne-prone, or combination skin. Those with congested pores, blackheads, or frequent breakouts.
AHA + BHA Together: The Best of Both Worlds
Many K-beauty formulas combine both acids for comprehensive exfoliation — surface renewal and deep pore cleansing in a single step.
Beauty of Joseon Green Plum AHA BHA Toner is a perfect example. Formulated with green plum extract — naturally rich in AHAs — alongside BHA, it gently exfoliates the surface while clearing congestion deep within the pore. The result: smoother texture, clearer skin, and a brighter complexion with consistent use.
The green plum also delivers a dose of Vitamin C, adding brightening and antioxidant benefits to every application.
How to Use Acids Safely
Start slow. Begin with 2-3 times per week and observe how your skin responds before increasing frequency.
Apply to clean, dry skin. After cleansing, wait a minute before applying your toner or acid to ensure maximum efficacy.
Always follow with SPF. AHAs in particular increase photosensitivity. Using acids without sunscreen is counterproductive — and potentially harmful.
Don't layer with other actives. Avoid using AHA/BHA on the same day as retinol or Vitamin C until your skin is accustomed to each ingredient individually.
Listen to your skin. Some tingling is normal. Burning, stinging, or persistent redness is not — reduce frequency or concentration if this occurs.
The Glow Is in the Exfoliation
AHA and BHA aren't complicated — once you understand what they do and how to use them, they become two of the most reliable tools in your skincare arsenal. Consistent, gentle exfoliation is one of the fastest ways to transform your complexion.
Clearer skin isn't a mystery. It's chemistry.
Shop the Beauty of Joseon Green Plum AHA BHA Toner →