Skincare Ingredients You Should Never Mix

Posted by Brooklyn S. on

Are you a skincare enthusiast and spend so much time layering different skincare products every morning and evening to maintain radiant, supple, and smooth skin? Well, then you might be familiar with the significance of using the right ingredients. Picking out the right ingredients and layering them in the proper order can take your ordinary skincare routine to new heights. It allows each product to penetrate the skin and work to its optimal potential.

However, many of us don’t realize that combining certain ingredients can make a difference in how our skin feels and looks. If you’re not aware of the consequences of mixing different skincare ingredients and the mess it can create on your skin, keep on reading.

Why Does Mixing Different Ingredients Matter?

One of the most significant issues when combining different active skincare ingredients is that they can react with each other, causing stinging, itching, redness, uneven skin tone, and dryness. Another reason to avoid using certain active compounds together is that some ingredients can negate or neutralize the effects of other active ingredients or lower their effectiveness. Moreover, certain potent actives can destabilize other ingredients when applied jointly to the skin. Therefore, to ensure your skin doesn’t have to undergo several chemical experiments, which can affect it adversely, it’s crucial not to mix certain ingredients.

  • Retinol and Alpha Hydroxy Acids - Retinol belongs to the vitamin A family and is one of the most widely used skincare ingredients. Over the recent years, it has also become one of the most praised anti-aging skincare compounds. Retinol does its job by accelerating the rate of cell turnover and boosting the production of collagen in the skin. Similarly, AHAs are also commonly used for reducing and preventing the signs of aging by speeding up cell renewal and higher levels of collagen in the skin. Both ingredients result in a radiant and smooth complexion. However, since both of these compounds exfoliate the skin’s outer layer, they can cause flaking, dryness, and redness on the skin, mainly when used together. So, instead of applying products with both ingredients in combination, it’s better to use one of them at a time or apply them on alternate days.
  • Retinol and Benzoyl peroxide - As mentioned above, retinol is known for treating signs of aging, like fine lines, wrinkles, and age spots. In addition, it clears clogged pores, removing dirt, grime, sebum, bacteria, and other pollutants, which help reduce acne. It works as an anti-aging agent through its powerful exfoliating action, which amps up the skin’s natural repair and regeneration process. Benzoyl peroxide is a commonly used effective acne-fighting ingredient.¹ However, the combo of retinol and benzyl peroxide may prove ineffective and unsafe rather than providing you with better results because benzoyl peroxide can deactivate retinoid molecules, making retinol futile in yielding the desired outcomes. For this reason, you should always avoid combining these ingredients in your skincare routine or use one ingredient in your morning routine and the other at night.
  • Vitamin C and Retinol - We all adore vitamin C as our go-to product for many skin issues, whether hyperpigmentation, dark under-eye circles, wrinkles, dryness, or dull and uneven complexion. However, vitamin C molecules can be unstable and require an acidic pH level of the skin to be most effective. At the same time, retinol works best when the skin’s pH environment is alkaline (higher pH). Layering them together on the skin may not allow both ingredients to offer optimal benefits. Moreover, retinol is an exfoliator that enhances cell turnover and collagen production. Slathering it on the skin with vitamin C, an acid, can make the skin more sensitive and prone to irritation, sun damage, and peeling. It's best to use vitamin C in the AM as it’s a potent antioxidant that shields against oxidative stress during the day. Retinol is more suitable for nighttime.
  • Oil and Water-Based Products - It’s a no-brainer that oil and water-based products don’t get along very well because oil repels water. If you apply a water-based skincare product after applying an oil-based product, the oil will prevent water-based products from penetrating the skin.² When a product isn’t absorbed, it fails to perform its intended function in helping to treat skin problems. If you must apply both products in your skincare routine, follow the thinner to thicker consistency rule. First, apply thinner, water-based products, including toners, mists, and serums, and follow with thicker and oil-based products. This will allow both the products to enter the skin and do their work.
  • Retinol and Beta Hydroxy Acids - Acne and wrinkles are two common skin issues many of us face worldwide. Many of us are told to use retinol to get rid of saggy skin and acne breakouts. We are often drawn to adding other acne-fighting ingredients to our skincare regimens to combat acne better. Salicylic acid, a beta hydroxy acid, is a common compound that comes to mind when treating and preventing acne. However, like AHAs, combining retinol with BHAs can also be a recipe for disaster. Both ingredients stimulate cell turnover, helping to remove the buildup of dead skin, oil, and other impurities from the pores. Both can be irritating and drying on the skin. Now imagine using them both together. You’ll only be making your skin’s condition worse. So, use products with these ingredients more cautiously. Apply retinol product before bedtime and salicylic acid product in the morning. Keep the skin amply moisturized and hydrated to avoid any harsh effects.
  • AHAs/BHAs and Vitamin C - As mentioned earlier, vitamin C can be easily affected when combined with powerful ingredients. Vitamin C works well when the skin’s pH is acidic. However, the skin's pH balance is disturbed when vitamin c skincare products are layered with an AHA or BHA-based skincare product (like salicylic acid, glycolic acid, and lactic acid). Under such conditions, none of the ingredients will produce optimal results. Therefore, layering AHAs and BHAs with vitamin C can render them useless no matter how good your products are. The best approach is to apply these ingredients at different times during the day. Vitamin C is ideal for daytime use, while AHAs and BHAs are better at night.
  • AHAs/BHAs and Niacinamide - Niacinamide (vitamin B3) is added to skincare formulations for its extraordinary antioxidant, hydrating, and anti-inflammatory properties. It also helps to brighten dull complexion, smoothes out wrinkles, and treats uneven skin tone. However, when layered on the skin with AHAs and BHAs, it may not have any effect on the skin, making them ineffective ingredients for the skin. The reason behind this is the chemical reaction between these compounds. The pH of niacinamide is around 5 to 7. Therefore, it can increase the pH level of alpha and beta hydroxy acids and cancel out their effects on the skin.³ Therefore, to acquire these ingredients' anti-aging, soothing, anti-acne, and exfoliating benefits, use them separately.
  • Sunscreen and Other Products - We are all well-versed with the significance of applying and reapplying sunscreen every day. It can help prevent several skin issues, including premature wrinkles, fine lines, age spots, melasma, and even skin cancer. While sunscreen is crucial for every skin routine, it may seem like an extra step to slather on sunscreen every day. If you’re thinking about combining it with your moisturizer or makeup products to save some time, you might be reducing its effectiveness in protecting the skin against environmental aggressors. Apply a good amount of sunscreen and let it properly absorb into the skin before applying your makeup or other skincare products. 

Final Thoughts

While it’s essential to feed your skin with the right ingredients and apply them in the correct order to reap maximum benefit from your skincare products, it’s equally significant to avoid using certain skincare ingredients together. Various ingredients work well together and may boost their efficacy, while many may destabilize or neutralize other active compounds and reduce their effectiveness. Also, some ingredients can cause chemical reactions on the skin and lead to dry, irritated, flaky, and inflamed skin. Many compounds need different conditions to produce their optimal effects without causing any damage to the skin, providing you with the sought-after results.

Hence, it’s imperative to know which ingredients are safe to use together and should never be mixed. We hope the above list will enable you to adopt a skincare routine and achieve optimal effects of your skincare ingredients.




  1. Cherney, Kristeen. (2019). ‘How to Treat Acne with Benzoyl Peroxide’, Healthline. Accessed May 12, 2022. Available at:,for%20mild%20to%20moderate%20breakouts.
  2. Fellizar, Kristi. (2019). ‘Oil Based vs. Water-Based Beauty Products – What’s Better for You?’, FabFitFun. Accessed May 12, 2022. Available at:
  3. Mukherjww, Tiarra. (2019). ‘What Is Skin pH? How to Tell if Yours is Healthy, and Why It Matters’, EverydayHealth. Accessed May 13, 2022. Available at:

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