How to tell if you’re using *too* many skin-care ingredients at once

As I once learned after eating an entire bag of Sour Patch Watermelons that left me with an actual sugar hangover the next morning, there is definitely such thing as “too much of a good thing.” And this morning, as I layered my moisturizer on top of my hyaluronic acid, vitamin C, and AHA serums, I had a thought that stopped me in my tracks: Could this principle apply to skin care, too? In other words, is it possible to use too many active ingredients at the same time?

“There’s no limit on number, but I think most dermatologists would agree that less is more,” says New York City-based dermatologist Dhaval Bhanusali, MD, FAAD. “Especially if ingredients are drying, like exfoliators, you can strip away the good oils and actually cause compensatory hyper-secretion of oil into the pores and more breakouts.” As in—your skin will produce more oil, which, he says, is one of the major culprits behind adult acne.

“There is not one magic ‘one size fits all’ number of actives that a person can use,” confirms board-certified dermatopathologist Gretchen Frieling, MD, noting that people have different skin care types, conditions that they wish to address, and tolerance levels for products, all of which can influence how your skin responds to different ingredient cocktails.

While there may not necessarily be a thing as “too many” actives, if you do plan on combining a whole bunch of them at once, you’ll want to be mindful of what they are. For example, the 10-step Korean skin-care routine has a lot of different actives in it, but most of them tend to be simple and calming, so using them one after the other likely won’t cause any sort of reaction. When it comes to combining strong chemical exfoliants (like AHAs and BHAs) and retinoids though, it’s another story.

“This may potentiate the irritating effects and cause excessive dryness or erythema, AKA redness,” says Dr. Bhanusali, adding that he likes to spread out the use of antioxidants in the morning and retinols at night so as not to overwhelm the skin. As for whether or not it’s okay to combine exfoliating acids with vitamin C, he says it’s technically fine, but some acids can effect the stability of your vitamin C serum. If you are going to mix them as a part of the same routine, wait 30 minutes between each layer or use one in the morning and one at night. However, Dr. Frieling says that if you want the “full impact and quick results” of your brightening vitamin C serum, you’re better off keeping them separate.

A few good rules of thumb worth following as you put together an active-heavy routine: Use a cleanser and either an antioxidant, like vitamin C, or an exfoliant, like glycolic acid, in the morning, alternating between the two. At night, keep things simple with a cleanser, a retinol, and a hydrating mask. And remember (once more for the people in the back!), less. Is. More.

Seriously—this “less is more” attitude has inspired an entirely new trend of “skip care” among former 10-step aficionados. If you want to cut back on your own routine, here’s how to put together a skin-care wardrobe that includes everything you need and nothing you don’t.