Glycolic Acid

Glycolic acid and retinol both promote cell turnover. While this is listed as a retinol + glycolic acid interaction, the reverse pairing confirms: layering both increases irritation risk. Best separated to AM/PM or alternating nights.

Layering AHA (glycolic acid) and BHA (salicylic acid) together increases the risk of over-exfoliation, redness, and barrier damage for most skin types. Best used on alternating days or in separate routines.

Both are alpha-hydroxy acids (AHAs) that exfoliate the skin. Using two AHAs together significantly increases the risk of over-exfoliation, irritation, and barrier damage. Choose one AHA per routine rather than layering both.

Both glycolic acid and L-ascorbic acid are highly acidic. Using them together can drop skin pH too low, leading to stinging, redness, and irritation. Apply at different times of day for best tolerance.

Glycolic acid exfoliates dead skin cells and enhances absorption, while hyaluronic acid replenishes moisture to freshly exfoliated skin. This pairing delivers both renewal and hydration.

The low pH environment created by glycolic acid can destabilize copper peptides (GHK-Cu), reducing their efficacy. Apply peptides after the skin has returned to its normal pH, or use them at a different time of day.

Using retinol with glycolic acid increases the risk of irritation, redness, and peeling. Both accelerate cell turnover, and layering them can overwhelm the skin barrier. Use at different times of day (AHA in AM, retinol in PM) or on alternating nights.

SLS disrupts the lipid barrier and enhances penetration of other irritants. When followed by glycolic acid, the risk of irritation, stinging, and redness is significantly increased.

Niacinamide helps soothe and repair the skin barrier after glycolic acid exfoliation. It also reduces the redness and irritation that glycolic acid can cause, making this a well-balanced pairing for skin renewal with minimized side effects.