Lactic acid
An alpha hydroxy acid that exfoliates the skin and helps to improve skin texture and tone.
Regulatory Info
Can I mix Lactic acid with other ingredients?
Using AHA and BHA together is aggressive exfoliation that can strip the skin barrier. Use on alternate nights for best results.
Other AHAs (Glycolic, Lactic, etc.)
Layering multiple AHAs (e.g. glycolic + lactic) is excessive. One AHA per routine is enough. More doesn't mean better.
Retinoids and AHAs are both strong exfoliants. Using them together can cause severe irritation, redness, and barrier damage. Alternate on different nights.
General guidance
AHAs increase UV sensitivity. Make sure SPF is in your morning routine when using AHAs.
PHAs
Using AHA and PHA together increases total exfoliation. PHAs are gentle but adding them to AHAs may be too much for sensitive skin.
Vitamin C with AHAs can be too acidic for some skin types. If you experience stinging, use them in separate routines.
Peptides
AHAs can reduce peptide effectiveness. Best to use acids and peptides in separate routines for maximum benefit.
Growth Factors
Growth factors like EGF may lose effectiveness when layered with AHAs. Consider using in separate routines.
AHAs lower skin pH while niacinamide works best at neutral pH. Together they may reduce niacinamide's effectiveness. Consider using on alternate routines.
Both are drying. Benzoyl peroxide with AHAs can over-dry and irritate skin. If you use both, apply on alternate days.
Hydroquinone
AHAs increase hydroquinone penetration, which can cause more irritation. Use lower concentrations if combining.
Azelaic acid with AHAs can cause irritation for sensitive skin. Both exfoliate through different mechanisms so go slowly.
Tranexamic acid is generally safe with AHAs, but combining multiple brighteners with exfoliants can irritate sensitive skin.
Denatured Alcohol
Alcohol-based products with AHAs increase drying effect and potential irritation. Look for alcohol-free formulas.
AHAs increase arbutin penetration, which can cause mild irritation on sensitive skin. Use lower concentrations if combining.
Glycolic acid + ceramides is a smart pairing. The acid exfoliates while ceramides immediately repair the barrier.
Unlike retinol, bakuchiol is stable at acidic pH and does not conflict with AHAs. No need to separate them — you can safely use both in the same routine.
Read all ingredient interaction guides for layering order and science-backed advice.