Glycolic Acid + Physical Scrubs / Manual Exfoliants
Avoid Combining
These ingredients should not be used together. The combination risks significant skin damage.
Combining physical scrubs with glycolic acid causes double exfoliation that damages the skin barrier and causes micro-tears.
What the Research Says
Physical scrubs (containing particles like sugar, walnut shell, microbeads, or ground pumice) exfoliate mechanically by physically abrading the skin surface. Glycolic acid exfoliates chemically by dissolving intercellular bonds. Using both methods on the same day subjects the skin to two fundamentally different types of exfoliation in rapid succession, which is far more aggressive than either method alone.
The primary risk is over-exfoliation and micro-trauma. Physical scrubs, even gentle ones, create microscopic abrasions in the skin. Applying glycolic acid to micro-abraded skin means the acid penetrates deeper and more unevenly than intended, concentrating in the tiny wounds and causing stinging, burning, and potential chemical irritation in the damaged areas. This can lead to post-inflammatory hyperpigmentation, especially in darker skin tones.
Furthermore, if you are using glycolic acid effectively, you simply do not need physical scrubs. Glycolic acid provides more uniform, controlled exfoliation than any scrub can achieve. Physical scrubs are an older approach to exfoliation that has largely been superseded by chemical exfoliants in evidence-based skincare. Most dermatologists recommend choosing one method and sticking with it.
Timing & How to Use
Do not use physical scrubs on the same day as glycolic acid. If you prefer occasional physical exfoliation, use it on a day when you skip glycolic acid entirely, and wait at least 24 hours before resuming glycolic acid. Better yet, replace physical scrubs with glycolic acid entirely.
Practical Tips
- 1If you are using glycolic acid regularly, you do not need physical scrubs at all
- 2If you must use a scrub, choose one with soft, round particles (jojoba beads) rather than jagged particles (walnut shell)
- 3Never use a scrub immediately before or after applying any chemical exfoliant
- 4A soft washcloth provides gentle mechanical exfoliation if needed between acid treatments
References
- Rodan K, et al. Skincare bootcamp: The evolving role of skincare. Plast Reconstr Surg Glob Open. 2016;4(12 Suppl):e1152.
- Tang SC, Yang JH. Dual effects of alpha-hydroxy acids on the skin. Molecules. 2018;23(4):863.
- Draelos ZD. The art and science of new advances in cosmeceuticals. Clin Plast Surg. 2011;38(3):397-407.
