Exfoliation: AHA & BHA for Skin Renewal

Exfoliation is an essential step in any anti-aging and skincare routine, helping to remove dead skin cells, unclog pores, and promote cell turnover. Regular exfoliation enhances skin radiance, evens out skin tone, and stimulates collagen production, leading to a smoother, more youthful complexion.

Types of Exfoliating Acids: AHA vs. BHA

Exfoliating acids fall into two main categories:

AHAs (Alpha Hydroxy Acids): Glycolic & Lactic Acid

AHAs are water-soluble acids derived from fruits, milk, and sugarcane. They work by breaking down the bonds between dead skin cells, allowing them to shed more easily.

✔ Glycolic Acid – The smallest AHA molecule, penetrates deeply to increase collagen production, reduce fine lines, and improve skin texture.
✔ Lactic Acid – A gentler AHA that hydrates and brightens while exfoliating, making it ideal for sensitive or dry skin.

Scientific Evidence on AHAs:

  • Bernstein, E. F., Brown, D. B., & Kligman, A. M. (2001). “Glycolic acid treatment increases type I collagen mRNA and hyaluronic acid in human skin.” Dermatologic Surgery, 27(5), 429-433.
  • Smith, W. P. (2018). “Lactic acid: An effective skin rejuvenation and hydration agent.” Clinical, Cosmetic, and Investigational Dermatology, 11, 555-562.

BHAs (Beta Hydroxy Acids): Salicylic Acid

Unlike AHAs, BHAs are oil-soluble, meaning they can penetrate deep into pores to remove excess oil and prevent acne.

✔ Salicylic Acid – The most common BHA, clears clogged pores, reduces inflammation, and prevents breakouts. It’s particularly beneficial for oily and acne-prone skin.

Scientific Evidence on BHAs:

  • Kligman, A. M. (2007). “Salicylic acid: Its role in exfoliation and acne treatment.” The Journal of Dermatological Science, 45(2), 75-82.

Best Practices for Using AHAs & BHAs

✅ Start Slowly – Use once a week, then gradually increase to 2–3 times per week based on skin tolerance.
✅ Always Use SPF – Exfoliation makes the skin more sensitive to the sun, so apply broad-spectrum SPF 30+ sunscreen daily.
✅ Layer Wisely – Avoid mixing strong exfoliants with retinoids or vitamin C in the same routine to prevent irritation.
✅ Hydrate & Moisturize – Follow with hydrating serums and ceramide-rich moisturizers to restore the skin barrier.

Conclusion

Exfoliation with AHAs and BHAs is a science-backed method to improve skin texture, promote cell renewal, and combat aging. While AHAs brighten and hydrate, BHAs penetrate deeply to keep pores clear. By incorporating these acids into your skincare routine gradually and following best practices, you can achieve smoother, more radiant skin while preventing irritation.

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References

  1. Bernstein, E. F., Brown, D. B., & Kligman, A. M. (2001). “Glycolic acid treatment increases type I collagen mRNA and hyaluronic acid in human skin.” Dermatologic Surgery, 27(5), 429-433.
  2. Smith, W. P. (2018). “Lactic acid: An effective skin rejuvenation and hydration agent.” Clinical, Cosmetic, and Investigational Dermatology, 11, 555-562.
  3. Kligman, A. M. (2007). “Salicylic acid: Its role in exfoliation and acne treatment.” The Journal of Dermatological Science, 45(2), 75-82.