So you've got yourself a stash of serums (which collectively look very chic in your bathroom) and you know each of their potent, individual benefits. But what about their combined effects?
Here’s a look at some active combinations that are disruptive to your skin or cancel each other out.
Vitamin C + Acids = nope
The vitamin you associate with zesty citrus fruit is officially having a moment—one that it deserves, frankly, for its antioxidant and brightening properties. But if you’re trying to light up your complexion or tone down pigmentation, there’s something we should tell you: Vitamin C is a rather unstable active. This means if you pair it with acids like lactic, glycolic or malic, it’ll lose its magical properties. Sad but true.
Best to ensure your face is meticulously rinsed of cleanser and patted dry before applying C. This way, your skin is accepting its full, uncompromising power.
The caveat here? Hyaluronic acid. It's a moisture-binding ingredient that retains hydration—It's also the conduit in our KILLA patch that pushes the ingredients directly into the heart of your zit. 
Retinol + Acne-specific ingredients = Nope
Benzoyl peroxide and salicylic acid (a foundational ingredient in our KILLA patch): We’re looking at you. Mixing these exfoliating agents with retinol (alias: Vitamin A) which works to heighten cell turnover will typically cause irritation and redness. Further, each of these ingredients encourages photosensitivity, and so using them in tandem may fast-track you to achieving the very red face you never signed up for. You’re best off using any of these products alone and in the evening to minimize sun interactions. And always wear SPF50. You wouldn’t dream otherwise though, right? Which is the perfect segue into our next point...
Sunscreen + moisturizer = Nope
These two should always be layered independently to maintain SPF integrity and efficacy. Sunscreen needs to be applied over your moisturizer as your final skincare step (before makeup) in order to best serve its UV-blocking duties.
But hey, it’s not all bad news—some actives are actually synergistic...
Hyaluronic acid + retinol or exfoliating acids = Yes
As outlined up above, retinol and exfoliating acids like lactic or glycolic acid can be taxing on the skin’s barrier. Re-injecting hyaluronic stores (which naturally occur in both the skin and in ZitSticka) will up moisture, hyper-fast. HA’s composition is fine enough that the efficacy of these other products won’t be compromised.
Vitamin E and Vitamin C = Yes
These nourishing, remedial vitamins team up to address different ]layers of the skin. Add some E (which happens to be in our CLEANA swab) to your C to really turn up its ability to fade hyperpigmentation.
And last of all: the natural order of things. Serum first, so it’s quickly absorbed into fresh skin. Moisturizer last of all, to seal in all your hard work. A toner, essence and/or oil sandwiched between the two, if you’re so inclined ♡
