Skincare Ingredients That Don’t Mix Well Together

If you’ve mastered reading ingredient lists and picking products that suit your skin, it’s time to level up: learning which ingredients play nice together—and which don’t.

Some popular actives can cancel each other out or, worse, cause irritation when used together. Here are the top combos to avoid in your skincare routine.

Retinol + Vitamin C
Both brighten, fight pigmentation, and target wrinkles. But combining retinol (vitamin A) and vitamin C at once can lead to redness and irritation.

Instead, split them: vitamin C in the morning, retinol at night. Retinol is light-sensitive, so it’s best used after dark—and always with SPF. Want a better match? Pair retinol with hydrating hyaluronic acid or antioxidant ferulic acid to reduce dryness and inflammation.

Retinol + AHAs
Using retinol and alpha hydroxy acids (like glycolic acid) at the same time can overwhelm your skin, leading to dryness, redness, or breakouts. Both can weaken the skin’s barrier.

Rotate instead: use AHAs a couple of days a week, and retinol on the others. If irritation appears, take a break from both.

Retinol + Salicylic Acid
Retinol and salicylic acid (a BHA) are strong solo players—but too harsh together. They both exfoliate and increase sun sensitivity, which can lead to peeling, dryness, or pigmentation.

A gentler alternative: swap retinol for niacinamide. This ingredient calms inflammation, controls oil, and refines pores. Just don’t mix niacinamide with acids—use them at different times of day for best results.

Salicylic Acid + Glycolic Acid
Layering BHA and AHA acids may sound like a power move, but it can strip the skin’s moisture barrier, causing dehydration. Dry skin may get flaky; oily skin might overcompensate with more sebum.

Stick to one type of acid at a time, and don’t overdo it—more is not always better.

Vitamin C + AHAs
Fruit acid toners and vitamin C serums don’t mix well. At best, acids will neutralize vitamin C’s benefits. At worst, they’ll trigger peeling and itching.

Instead, pair vitamin C with stabilizers like ferulic acid or antioxidant-rich vitamin E. It also works well with niacinamide—despite old myths suggesting otherwise.

Peptides + Almost Everything
Peptides are potent and versatile—they target wrinkles, calm skin, and even mimic Botox. But they’re sensitive.

Mixing them with retinol, vitamin C, or acids can deactivate their effects. For best results, use peptide products from the same brand line—these are formulated to work together.

This advice applies when these “clashing” ingredients come from different products used at the same time. If they appear together in a single formula, don’t worry—brands often fine-tune concentrations and delivery methods to ensure compatibility.