Pick up any magazine, click on any beauty article regarding “active ingredients,” or better yet ask a dermatologist what they’d recommend to hit the pause button on aging skin, and you’ll undoubtedly hear that in the morning, you should slather on  sunscreen…and lots of it. As for the nighttime, things get more divided because the pros recommend the powerhouse ingredients retinol and glycolic acid in equal measure…so much so that I wondered which of the two is actually queen of the skin-care aisle.

What I found out was that the reason that they’re named equally among dermatologists is that the answer is kind of a toss-up. Things like skin type, your skin age, and overall #skingoals hugely come into play here, so knowing the resumes for each could help you find your best skin on repeat. Here, dermatologist share how to use the two star players and how to determine which one is right for your regimen.

How do glycolic acid and retinol work?

Okay, so to kick things off: It’s important to understand what each of these active ingredients is doing for your skin. Let’s start with glycolic acid. “It’s one type of alpha hydroxy acid and a chemical exfoliant that removes dead skin cells by loosening the ‘glue’ that holds the dead cells to the top layer of skin,” explains Dennis Gross, MD, a New York City dermatologist and founder of Dr. Dennis Gross Skincare. “Once these dead cells are removed, new youthful cells are revealed.”

By consistently removing the top layer of dead skin cells, you uncover the new ones which is good for a number of reasons. First off, your treatment products like peptides, for instance, penetrate the skin more deeply without having to first traverse a layer of over-it skin cells. They, also, he says help to speed up cell turnover—which slows down as you get older—in order to reduce the appearance of fine lines and wrinkles.

Retinol, on the other hand, is a vitamin A derivative that does a ton of different things. It’s often used to treat acne because it, too, helps to speed up cell turnover, keeping dead cells from chilling on your complexion and plugging your pores. As an anti-ager, it offers the benefit of stimulating collagen production as well. This is super important, because, as we age, we produce less and less collagen, which can often lead to skin laxity.

“It can improve the texture of your skin some too, but it’s really known for decreasing fine lines and wrinkles,” says Jeanine Downie, MD of New Jersey’s Image Dermatology. “And it does that by boosting collagen and elastin, which are building blocks of your skin.”

What else can the two ingredients do?

Helping you prolong fine lines and wrinkles isn’t the only thing these products are good for. “Glycolic acid tends to be more mild than a retinol, and is ideal if your concerns are more focused on dull or tired looking skin,” says Dr. Gross. “It gives skin a radiant glow, reduces the appearance of pores, fades discoloration, helps prevent and treat breakouts and improves overall texture.” So, in short, if you’re looking for a quick way to bring a glow to your complexion, look no further.

For its part, retinol does work overtime to help with zits. “I’ll put prescription Retin-A on [a zit] three days in a row and just deal with the flaking, because I want the zit gone,” says Dr. Downie. “They work great as an anti-acne remedy.” Retin-A is the prescription-strength iteration of retinol so you can get an even more of an impact if your dermatologist deems it necessary.

It’s important to note that both glycolic acid and retinol can make skin more photosensitive, or in other words, more likely to get burned by the sun. If you add either to your routine, make sure to glob on the SPF in the mornings to make sure that you’re protected.

So, which one should you be using?

Turns out, it’s not really an “either/or” decision with retinols and glycolic acids.  “The key is to use both ingredients as part of your overall anti-aging skin-care regimen,” says Dr. Gross.  “They work differently yet join forces to provide a wholesome healthy rejuvenating treatment for your skin.” He suggests starting with an AHA at around age 24, then adding a retinol in your mid- to late- 20s when cell turnover and collagen production start to slow down.

Look for a glycolic acid that contains other AHAs and BHAs at low concentrations, which allows you to target multiple skin-care concerns at once and won’t be as irritating as a hardcore glycolic peel. Avoid layering them along with prescription retinoids, like Retin-A, benzoyl peroxide, and instead use on at morning and one at night.

Because retinol generally tends to be drying, you’ll need to taper your use based on what kind of skin you have. If you’re on the oilier side, you should be good to go 7 days a week, but if you have dry or combination skin, you should only be applying one to three times a week to keep you skin from getting aggravated. Take note: since retinol’s job is to speed up cell turnover, that can mean that you might get some degree of peeling. It’s normal. No, seriously everyone goes through it. If it seems excessive, check in with your derm, who can problem solve it by switching up how many days a week to use your product. Otherwise, slather on your way to better skin.

Can you use glycolic acid and retinol together?

Glycolics work from the top down, while retinols do their thing from the bottom up. “Working them in together is complicated because they can both dry out the skin,” explains Virginia-based dermatologist Lily Talakoub, MD, so you’re going to want to up your dose of hydration and really tune into what your skin is telling you. While those with normal-to-oily skin are fine to give the coupling a go, if you’re on the drier or more sensitive side, start with a glycolic acid and give your skin time to adjust. “If you’re doing great with that and have no irritation, then you can add in the retinol,” she explains.

The most important thing to keep in mind when using two ingredients, is hydration, hydration, hydration.  Dr. Talakoub notes that you should slather your skin with two coats of moisturizer (your usual followed by a second helping 10 minutes later after it’s soaked in), and add a hyaluronic acid step for some bonus moisture.

Sure, sure, doubling down on glycolic acid and retinol might make your routine longer and pricier (and take up slightly more space in your medicine cabinet), but for the sake of a true skin-deep, inside-out glow, I’m officially calling it “worth it.”

Shop glycolic acids

Farmacy Honeymoon Glow AHA Resurfacing Night Serum with Echinacea GreenEnvy — $58.00

This overnight serum is a triple-threat for dull, dehydrated, and generally congested skin. It’s made with a highly concentrated blend of AHAs, BHAs, and floral acids, and works to resurface, clarify, and hydrate your complexion while you sleep. It’s gentle, yet effective, making it a worthy investment for all skin types.

Drunk Elephant T.L.C. Framboos Glycolic Resurfacing Night Serum — $90.00

Considering this glycolic acid formula is so popular it’s been repurposed as a scalp scrub and a body lotion, you know it’s the real deal. The serum has been one of Drunk Elephant’s hero products since the brand’s launch nearly a decade ago, and helps to even skin tone and decongest pores

Dr. Dennis Gross Alpha Beta Extra Strength Daily Peel — $88.00

Our editors are die-hard fans of these derm-developed peel pads, and it’s for good reason: They combine skin-resurfacing AHAs with ultra-effective BHAs, which get way down deep into your pores to clear out gunk and prevent breakouts and congestion. Use ’em on your face and body for a clear complexion all over.

Ole Henriksen Invigorating Night Transformation Gel — $38.00

“Transformation” is the key word here, because this serum uses a blend of AHAs to tackle both skin tone and texture, making discoloration and fine lines and wrinkles nothing but distant memories.

Dior Capture Youth Serum Collection — $95.00

Give your routine a little bit of luxury with this youth-renewing serum, which pairs AHAs with vitamin C for the ultimate brightening cocktail.

Vivant Skin Care Exfol-A Level 2 — $68.00

This serum’s got all of the heaviest hitters in the AHA world, including glycolic, lactic, and kojic acids. While these ingredients work to exfoliate, niacinamide’s nearby to soothe skin and reduce irritation.

iS Clinical Active Serum — $138.00

The great thing about this serum is that it gives your complexion both short and long-term effects. Immediately after applying, you’ll feel some tingling and see instantly brighter skin, and over time it will do away with hyperpigmentation, redness, acne, and textural issues like fine lines and wrinkles.

Shop retinols

Sunday Riley A High-Dose Retinoid Serum — $122.00

This vitamin A serum truly is A+. It pairs retinol with texture-boosting CoQ10 and skin-soothing Hawaiian white honey for an anti-aging formula that does its job without irritation.

SkinMedica Age Defense Retinol Complex 0.5 — $78.00

With a 0.5 percent retinol concentration, this stuff packs a serious punch in fighting off signs of aging. Plus, algae extract aids in hydration and helps to protect against free-radical damage.

PCA SKIN Intensive Clarity Treatment 0.5 Pure Retinol Night — $111.00

If acne is your primary concern, this is the retinol formula for you. In addition to its retinoid element, which stimulates cell turnover to limit your breakouts and smooth the surface of your skin, it’s also got witch hazel, which helps to control the excess oil that causes pimples in the first place.

SENTÉ Bio Complete Serum — $118.00

This serum’s got an entire laundry list of ingredients to help you fend off signs of aging. Yes, there’s retinol, but there’s also collagen-stimulating peptides and free-radical fighting vitamin C, aka everything you need to keep your skin bouncy and clear.

First Aid Beauty FAB Skin Lab Retinol Serum 0.25 Pure Concentrate — $58.00

Consider this your entry-level retinoid. With a 0.25 percent concentration of the ingredient, it’s strong enough to be effective but gentle enough to be used on all skin types.

Resist Intensive Wrinkle-Repair Retinol Serum — $42.00

As one of the more concentrated retinoids on this list (its formula has 0.1 percent of the stuff), this serum will plump your skin in no time at all. It goes on silky smooth, and is great for use at any age.

Murad Retinol Youth Renewal Serum — $89.00

With three types of retinol—an instant release version, which works to instantly plump skin, a time-release version, that continues this plumping effect for the long haul, and a retinol booster to ensure that these ingredients are working to their full potential—this serum works overtime to plump and smooth skin. It’s no wonder it’s a beauty-editor favorite.

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