As a board-certified, double fellowship-trained cosmetic dermatologist with a private practice in Newport Beach, California, I provide unsponsored, unbiased, science-based content on Youtube and in this Blog to help you make better skincare decisions. In this week's video we’re tackling a common question: Are there skincare actives that you shouldn’t layer together? What should I know?
Let’s break down what’s safe, what’s not, and how to optimize your skincare regimen for healthy, glowing skin. And of course if you want more detail be sure to check out the full Youtube video!
The Biggest Concern: Irritation and Barrier Disruption
When layering skincare actives, the biggest risk is irritation, particularly when combining chemical or mechanical exfoliants with other active ingredients. Any exfoliant—whether chemical (like AHAs and BHAs) or mechanical (like scrubs)—can compromise your skin’s barrier, making it more susceptible to irritation from other actives.
If your skin barrier is disrupted by exfoliation (or treatments like lasers), the absorption of active ingredients increases dramatically, which can lead to irritation, redness, and dryness. That’s why it’s essential to introduce new actives gradually—typically at two-week intervals—to see how your skin reacts before adding more.
Actives That Work Well Together (With Proper Application)
Vitamin C and Retinol: A Powerful Duo
Vitamin C and retinol are two powerhouse ingredients that can deliver dramatic skin health benefits. They both play well together, but application timing is key because they absorb best at different pH levels:
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Vitamin C(Ascorbic Acid): Prefers an acidic pH and works best in the morning to brighten, protect, and correct.
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Retinol: Prefers a neutral pH and is best used at night to renew and restore the skin.
If you want to use both morning and night, make sure your retinol is photostable (meaning it won’t break down in sunlight). In the morning, apply vitamin C first, wait for absorption (30-60 seconds), and then layer retinol. However, the safest approach is to use vitamin C in the morning and retinol at night.
Not all vitamin C formulations are effective—look for L-ascorbic acid, the most potent and scientifically proven form. It should have a rapid absorption delivery system to maximize bioavailability. My MDAiRE Vitamin C FK, for example, absorbs in under a minute, allowing you to layer other products without interference.
Exfoliants and Retinol: A Strategic Approach
Exfoliating acids like AHAs (lactic acid, glycolic acid) and BHAs (salicylic acid) improve skin texture, brighten complexion, and help unclog pores. However, they also increase skin sensitivity, so combining them with retinol can lead to excessive irritation.
A smart approach is to alternate use:
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Use retinol on some nights and exfoliants on others.
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If you’re experienced with skincare, you may tolerate a gentle exfoliant in the morning and retinol at night.
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Beginners should avoid using both on the same day to prevent over-exfoliation and irritation. However a well formulated retinol like my RXR Retinol will be microencapsulated which will allow the active ingredient to get to where it needs to in the skin without causing much irritation.
Benzoyl Peroxide and Retinol: A Clash of Functions
Benzoyl peroxide is a powerful acne-fighting ingredient, but it’s an oxidizing agent, whereas retinol is an antioxidant. When used together, benzoyl peroxide can deactivate retinol, reducing its effectiveness.
To avoid this conflict:
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Use benzoyl peroxide in the morning and retinol at night.
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If your skin can tolerate it, alternate nights for each active.
Customizing Your Routine for Maximum Results
Your skincare regimen should adapt to your skin type, tolerance, and environmental factors like climate, humidity, and travel. Even if you’ve been using an active ingredient for months, changes in weather or exposure to different conditions can impact how your skin reacts.
Golden Rules for Layering Skincare Actives:
✅ Introduce new actives gradually (every two weeks).
✅ Use vitamin C in the morning and retinol at night for best results.
✅ Avoid layering exfoliants and retinol on the same day unless your skin is highly tolerant.
✅ Keep benzoyl peroxide and retinol separate to maintain efficacy.
✅ Always prioritize hydration and sun protection to support your skin barrier.
By understanding which actives can be safely combined and how to layer them correctly, you can build a skincare routine that enhances your skin’s health without unnecessary irritation.
