In the realm of skincare worship, there exist a few cardinal sins. Trespasses like sleeping in make-up, neglecting sunscreen, and succumbing to the temptation of pimple popping are well-known amongst even the most faithful of followers. It stands to reason, then, that even the most ardent of skincare devotees are thus susceptible to the heedless mixing of skincare ingredients.
Such a transgression is understandable. With beauty empires peddling a tempting buffet of products, the zealous customer is often spoiled for choice, overwhelmed by a smorgasbord of serums and salves, and then, subsequently, bound for regret. You see—not all skincare cocktails are meant to be savoured. Retinols don’t pair well with AHAs/BHAs,vitamin C shouldn’t be applied with niacinamide, and SPF should never be mixed in with make-up.
So, pay heed to this enduring skincare doctrine: Too much of a good thing can be a bad thing. But don’t just take our word for it; let seasoned aesthetic doctor, Dr Rachel Ho, explain the science behind pernicious skincare concoctions, and which ingredients to combine instead. Below, a skincare mixology 101 from an expert’s point of view.
Don’t: Mix with benzoyl peroxide or AHAs/BHAs
Skincare’s holy grail of anti-ageing solutions works wonders to rejuvenate and refine the skin, effectively reducing the appearance of wrinkles and enlarged pores through exfoliation and cellular proliferation. However, if you find yourself grappling with skin irritation instead, chances are, you may have added benzoyl peroxide or AHAs/BHAs on top of your retinoid. As Dr Ho explains, the former oxidises retinol, rendering it ineffective, while the latter dries out the skin, leading to increased irritation.
Do: Mix with niacinamides, ceramides, and a layer of SPF
Au contraire, consider opting for other ingredients like niacinamide, ceramide, and SPF alongside your retinol treatment. These can assist in fortifying your skin’s barrier following the retinol-induced purging process.
2. Vitamin C
Don’t: Mix with AHAs/BHAs or a high-pH cleanser
“Vitamin C, also known as L-ascorbic acid, works better at a low-pH level,” advises Dr Ho. Therefore, incorporating a high-pH cleanser before a vitamin C serum may reduce the hydrating and brightening effects of the acidic agent. In a similar vein, combining vitamin C with other acidic ingredients such as AHAs or BHAs might inadvertently lead to skin irritation due to the compounded low-pH effect of both components.
Do: Mix with vitamin E, ferulic acid, and a layer of SPF
Instead, vitamin C junkies should reach for vitamin E or ferulic acid serums for dual antioxidant ammunition, or layer on SPF to enhance protection against sun damage.
Don’t: Mix with retinol, vitamin C, or niacinamide
Amidst the myriad of skincare benefits AHAs and BHAs offer, their ability to alleviate acne and rosacea -borne inflammation is perhaps the most illustrious. Nevertheless, the concurrent use of these acids with retinoids and vitamin C can potentially lead to transient irritation due to heightened cell turnover and exfoliation effects.
Do: Mix with moisturising ingredients, ceramides, and a layer of SPF
To counteract the potential effects of AHAs/BHAs—which include stripping the skin of its natural barrier and increasing UV sensitivity—Dr Ho recommends incorporating essential after-care steps with ceramides and SPF for holistic skin resilience.
4. Benzoyl peroxide
Don’t: Mix with retinol or vitamin C
Benzoyl peroxide is perhaps the most famous member of the BHA family, and a well-known ally for the 85 per cent of us who have dealt with acne. While its magic lies in paring down the amount of acne-causing bacteria on the skin, Dr Ho reveals that its oxidative qualities may also reduce the effectiveness of retinoids and vitamin C.
Do: Mix with moisturising ingredients and a layer of SPF
Given that benzoyl peroxide is classified as a BHA, it is privy to the same recommendations—moisturising, skin-barrier strengthening products and a generous daub of sunscreen.
Don’t: Mix with AHAs/BHAs or vitamin C
Implementing niacinamides into your skincare routine can be a tricky tango, as their effectiveness relies on maintaining a neutral pH level. Consequently, the presence of low-pH ingredients such as AHA/BHA and L-ascorbic acid can potentially compromise its efficacy. Dr Ho also cautions that at low pH levels, niacinamide can also hydrolyse to form nicotinic acid, which at high doses can induce a red, itchy niacin-flush on the skin.
Do: Mix with retinol, hyaluronic acids, and ceramides
Otherwise, niacinamide carries potent hydrating and toning properties that can be further amplified with other moisture-restoring ingredients like hyaluronic acid and ceramides. Niacinamide and retinol are yet another skincare power couple, as the former remedies the harsh exfoliating properties of the latter.
Don’t: Combine with make-up or skincare steps
Don’t get us wrong—make-up and skincare with built-in SPF are a plus in our books. The fault lies in swirling one dollop of SPF with one pump of foundation on the back of your hand, and applying the “2-in-1” to your face. Since sunscreens work by forming an even film on the skin, manually combining them with make-up or skincare to form a homogenous layer can implicate its propensity for sun-defence.
Do: Layer it on by itself
Skip the DIY science experiment and add a light weight, fast-drying SPF to your shopping cart instead. A bonus tip from Dr. Ho: Look out for sunscreens with hyaluronic acid for plump and protected skin.