Active ingredients that don’t go together

Why be careful?

Powerful actives each have their purpose, but applied together, they can irritate your skin: redness, tingling, flaking, a weakened skin barrier. Good news: it’s often enough to spread them between morning and evening, or across different days of the week.

Combinations to avoid on the same evening

• Retinoid and acid exfoliant (AHA, BHA): both speed up skin renewal, and together the risk of irritation goes up. Alternate evenings.
• Retinoid and benzoyl peroxide: the peroxide can break down some retinoids, and both are irritating. Use one in the morning and the other in the evening, or follow your dermatologist’s advice.
• Several exfoliants at once: a scrub with grains, then an acid, then a brush is too much. Use just one exfoliant, two to three times a week.
• Pure vitamin C (ascorbic acid) and exfoliating acids: both are acidic and can sting. Keep vitamin C for the morning and the exfoliant for the evening.

Combinations that work well

• Vitamin C in the morning and sunscreen: a complementary duo to protect your skin every day.
• Retinoid in the evening and moisturizer: the cream helps limit tightness. You can even apply it before the retinoid to soften its effect.
• Niacinamide and hyaluronic acid: gentle, and compatible with almost everything.
• Azelaic acid and niacinamide: a well-tolerated combination for blemish-prone or redness-prone skin.

What about niacinamide with vitamin C?

For a long time, people said they shouldn’t be combined. With current formulas, the combination is generally well tolerated. If your skin turns red, simply separate them: vitamin C in the morning, niacinamide in the evening.

A sample week

• Every morning: gentle cleanser, vitamin C, moisturizer, sunscreen.
• In the evening: retinoid three evenings, exfoliant two evenings, and two rest evenings with a hydrating serum.