Fashion and Beauty 3rd March 2022 by Amie Edmonds

PSA: These Are The Skincare Ingredients You Should *Never* Mix

Spoiler alert: Retinol and Vitamin C are not a match made in heaven.


When it comes to skincare, what to use, what not to use, what can be used together and what can’t be used together, it’s safe to say it can get confusing pretty quick.

Take it from me, who went heavy with salicylic acid paired with little to no knowledge and basically burnt my skin. Yep, not ideal. Mixing certain active ingredients can compromise the skin barrier and lead you down a dreaded path of inflammation, irritation and dehydration. Exactly the opposite of what we want when we excitedly first try a new skincare product.

So, we caught up with Skingredients Chemist, Gabriela Duffy Morales, to fill us in on exactly what skincare ingredients you should never pair together.

“It’s really important that you investigate the ingredients you are combining to ensure they are known to work well together and that you are applying them correctly,” says Gabriela. So, for the sake of your skin, it’s important to smartly layer ingredients to maintain skin health and help you reach your skin goals. Let’s get into it.

Retinol and AHAs & BHAs

“Retinol is a hero ingredient that boosts skin cell turnover, boosts collagen, supports sloughing of dead skin cells, and combats free radical activity to prevent cellular damage. To get nerdie, retinol is a derivative of vitamin A and natural precursor to retinoic acid. Once it’s absorbed into the skin, retinol must be converted into retinoic acid, which is the active form of vitamin A, for the skin to reap any benefits.


“Truth be told, retinol can cause sensitisation when mixed with some ingredients. Namely, when paired with exfoliating acids such as AHAs and BHAs which, like retinol, promotes the sloughing of dead skin cells. Using these ingredients in the same evening (you shouldn’t use either in the morning), you risk weakening the skin barrier which can manifest as redness, tight sensations and dehydration.

“In my nerdie opinion, use these active ingredients on alternate evenings – or even weeks if your skin is more sensitive. Notably, I would say that PHAs (polyhydroxy acids) are the exception to the rule as they’re a gentler AHA that exfoliates and acts as a humectant.”

Retinol and Vitamin C

“Retinol and Vitamin C aren’t a match made in heaven either. Vitamin C is an antioxidant that neutralises free radical activity caused by UV exposure, pollution and natural bodily processes. Free radicals (aka unpaired electrons) wreak havoc on skin cells which can lead to premature skin ageing. Vitamin C comes in many, many forms like vitamin A but I wouldn’t advise mixing any of them with retinol. Put simply, retinol and vitamin C are two powerhouse active ingredients that can lead to a lot of irritation when layered.

“The good news? There’s room for both ingredients in your skincare regimen. Apply Vitamin C underneath your broad-spectrum SPF in the morning as SPF shields skin from UV rays while vitamin C combats free radical damage caused by UV exposure. Then, use retinol at night to support the skin’s natural processes of cellular repair and proliferation which occur while we’re sleeping. Or switch to using retinyl palmitate, the gentlest form of vitamin A, which can be layered with vitamin C.”

Vitamin C and AHAs & BHAs

“Vitamin C packs a punch in terms of antioxidant protection but it’s an unstable ingredient that requires a particular pH balance to work wonders on your skin. Layering an AHA or BHA skincare product with vitamin C could disrupt and destabilise the pH balance which makes applying your vitamin C pointless.”

Furthermore, Gabriela advises that AHAs and BHAs should ideally be used in the evening because exfoliating acids can make our skin more susceptible to UV damage – even if you’re properly applying broad-spectrum SPF. Instead, stick to vitamin C in the mornings and use a BHA or AHA on the nights you’re not using retinol. Et voila, healthy, happy skin!

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