Glycolic Acid + Denatured Alcohol (Alcohol Denat.)
Use With Caution
These ingredients can be combined, but require careful timing, lower concentrations, or gradual introduction.
Drying alcohols can worsen the barrier disruption caused by glycolic acid - avoid them in your acid routine steps.
What the Research Says
Denatured alcohol (listed as alcohol denat., SD alcohol, or isopropyl alcohol in ingredient lists) is a common solvent in skincare that evaporates quickly and gives products a lightweight, fast-absorbing feel. However, it is also a potent skin-drying agent that strips lipids from the stratum corneum and increases transepidermal water loss. In products unrelated to your acid step, small amounts are generally tolerable for non-sensitive skin.
The problem arises when drying alcohols are combined with glycolic acid in the same routine. Glycolic acid already disrupts the skin barrier as part of its exfoliation mechanism. Adding a lipid-stripping alcohol amplifies barrier damage beyond what most skin can comfortably repair overnight. This can lead to chronic dehydration, irritation, and a compromised barrier that makes all subsequent products - including your moisturizer - less effective.
Note that fatty alcohols (cetyl alcohol, cetearyl alcohol, stearyl alcohol) are completely different and are actually beneficial emollients that help restore the skin barrier. The concern is specifically with short-chain, volatile alcohols that evaporate and dry the skin.
Timing & How to Use
Avoid applying products with high concentrations of drying alcohol immediately before or after glycolic acid. If a product you love contains some alcohol denat., use it at a different time of day from your glycolic acid step. Always follow glycolic acid with hydrating, alcohol-free products.
Practical Tips
- 1Check your toner and essence ingredient lists - these product categories most commonly contain drying alcohols
- 2Fatty alcohols (cetyl, cetearyl, stearyl) are safe and beneficial - do not confuse them with drying alcohols
- 3Alcohol-free glycolic acid products are available and preferred for most skin types
- 4If a product lists alcohol denat. in the first 5 ingredients, the concentration is significant
References
- Lachenmeier DW. Safety evaluation of topical applications of ethanol on the skin and inside the oral cavity. J Occup Med Toxicol. 2008;3:26.
- Fluhr JW, et al. Glycerol and the skin: Holistic approach to its origin and functions. Br J Dermatol. 2008;159(1):23-34.
- Rawlings AV, Harding CR. Moisturization and skin barrier function. Dermatol Ther. 2004;17(Suppl 1):43-8.
