Main content
A woman rubbing a lotion face cream into her face.


6 Common Retinol Questions, Answered

Are you wondering: What is retinol? You’re not alone. Here, a dermatologist answers your most pressing questions about retinol for skin.

Ask dermatologists what their favorite skincare ingredient is, and we’re willing to bet many will have the same response: retinol. This powerful and versatile ingredient is used to help address a wide range of skin concerns, including blemishes and premature aging —and when used correctly, it can produce impressive results. But as with any highly effective skincare ingredient, there are cons to match the benefits. Perhaps the most known drawback of retinol is that it can be irritating, particularly if you have sensitive skin. Its potential for irritation makes retinol one of the more tricky ingredients to acclimate your skin to, and retinol myths (and misconceptions) abound on the internet.

To help us separate fact from fiction, we called upon New York City dermatologist Dr. Michelle Henry to answer some of the most common retinol-related questions. Ahead, you’ll learn what retinol is and how it works, plus discover a few notable retinol benefits for skin. We’ll also dive into the difference between retinoids vs. retinol and provide expert-approved tips for incorporating retinol into your skincare routine. Read on for your ultimate expert guide to retinol for skin.

What Is Retinol?

Before we dive into how retinol works, we need to explain what it is. According to Dr. Henry, “retinol is a vitamin A derivative that is involved with skin turnover and skin regulation.” Though vitamin A itself isn’t a retinol, the two are structurally similar. This similarity, along with retinol’s ability to dissolve in the skin’s natural oil, allows retinol molecules to bind to specific receptors in your skin cells. These receptors then trigger various processes (like cellular turnover) to improve your skin’s texture and tone.

What Does Retinol Do For Skin?

When used topically, Dr. Henry says retinol has “a multitude of benefits.” “We often call it the holy grail of dermatological medications,” she adds. Most commonly, retinol is used to help address acne and visible signs of aging, though Dr. Henry notes that it’s also often found in products designed to help manage sagging skin, acne scars, and even dark spots and discolorations.

As for how it works, Dr. Henry explains that retinol is an antioxidant that helps improve skin’s natural turnover. “That process helps to unclog pores,” she explains, as well as help improve the appearance of areas with irregular or uneven skin pigmentation. It can also “help [improve the look of fine lines and wrinkles,” she adds. “It has a multitude of uses. It attacks most of our concerns regarding skincare.”

Micro-Dose Anti-Aging Retinol Serum

Retinol is a key ingredient in the aptly-named Retinol Skin-Renewing Daily Micro-Dose Serum, which also contains skin-strengthening peptides and ceramides. This highly effective retinol serum helps diminish the appearance of fine lines and deeper wrinkles. The lightweight, layerable serum is carefully formulated to help minimize the redness and irritation that can sometimes occur after initially using retinol and is safe enough for daily use—even for those with sensitive skin.

For eye-area concerns, like under-eye wrinkles and crow’s feet, reach for our Youth Dose Eye Treatment. This gentle yet effective eye treatment stars pro-retinol, a mild form of retinol suitable for use around the delicate eye area. It also contains vitamin C and grapeseed oil. The multi-powered anti-aging formula absorbs easily and immediately smooths the look of the delicate under-eye area. When used consistently, it visibly reduces fine lines, dark circles, and puffiness to promote a brighter, more youthful appearance. This retinol cream is suitable for all skin types and can be worn alone or under makeup.

Kiehl’s Tip: For extra hydration, layer Youth Dose Eye Treatment under a hydrating eye cream, like our cult-classic Avocado Eye Cream.

Retinoid vs. Retinol: What’s The Difference?

Retinoids and retinol are both derived from naturally-occurring vitamin A. However, different vitamin A derivatives affect the skin in different ways. According to Dr. Henry, the relative potency of a vitamin A derivative is closely linked to how it interacts with your skin cells. “When retinol encounters a cell, there are other enzymes required to get it to its most active state, which limits its potency,” she explains. These enzymes, which occur naturally in the body, convert the topical retinol into a substance called retinoic acid, which binds with your cells and stimulates cellular processes, like skin cell turnover.

Synthetic retinoids (such as tretinoin), meanwhile, are “closer to their active state,” Dr. Henry explains, and therefore more potent. In other words, retinoids don’t need to change into a different form to work properly the way natural vitamin A does. They’re effective all on their own.

While this potency can be beneficial for skin concerns like severe acne, it also comes with its disadvantages. Because retinoids are so strong, they can cause unwanted side effects, like dryness or irritation. If you’re using a retinoid, experts generally recommend adding an ultra-hydrating product into your skincare routine to help mitigate these potential side effects.

We recommend looking for a product that helps boost your skin’s natural hydration, like Hydro-Plumping Hydrating Serum. This powerful facial serum encourages your skin’s natural production of hyaluronic acid, a molecule closely involved with maintaining skin hydration and elasticity. When used regularly, this serum helps improve the look of dehydrated skin and promote a smoother, more even appearance. The ultra-gentle formula is suitable for all skin types and mild enough to use even on the highly delicate skin around your eyes.

Kiehl’s Tip: Before using retinol for acne, try spot-treating breakouts with Breakout Control Targeted Acne Spot Treatment, which helps rapidly reduce acne blemishes for visibly clearer skin.

How Should You Use Retinol?

Though retinol can be used to help manage a range of different skin concerns, you’ll typically use it the same way regardless of what issues you’re hoping to address. Dr. Henry has two pieces of advice for those looking to start using a retinol-based product. First: Start slow.

“I always recommend [starting with] once or twice a week, especially if you are super sensitive,” she says. “Many people can [better] tolerate it if they go slowly… and take some time [to] get accustomed to it.” If you have super sensitive skin, you also want to patch-test the retinol product first to ensure it doesn’t cause excessive irritation (Dr. Henry recommends doing this on your inner arm).

Her second piece of advice is to apply your product with what she calls “the sandwich method.” First, cleanse your face with a gentle, non-stripping cleanser, like Ultra Facial Cleanser. This Kiehl’s classic with olive-derived squalane and emollient avocado oil helps dissolve excess oil and other impurities without stripping the skin’s natural moisture barrier. Then, you can start the sandwich method.

According to Dr. Henry, this method involves “putting your moisturizer on, then putting on your retinol (or retinoid), and then [layering] moisturizer on top of that to help to diminish the chance that you’ll get irritation.” For this method—especially if you’re a retinol newbie—Dr. Henry recommends using a gentle moisturizer with “hypoallergenic, super-moisturizing ingredients,” like Ultra Facial Cream. This gentle yet deeply hydrating face cream with olive-derived squalane and glycerin nourishes the skin with non-greasy, 24-hour hydration. The customer-favorite formula is clinically-demonstrated to leave the skin softer, smoother, and visibly healthier with consistent use.*

*Results based on a four-week clinical test.

Kiehl’s Tip: Topical retinol and retinoids can make your skin more susceptible to sunburns. If you’re using any retinol-containing product, be sure to protect your skin with a broad-spectrum sunscreen, like Super Fluid Daily UV Defense 50+.

How Fast Does Retinol Work?

Good news: For the most part, retinol works pretty quickly. Whether you’re using a retinol cream, gel, or serum, Dr. Henry says you’ll generally see “early results at four weeks [and] final results at 12 weeks.” And before you ask, yes, this applies to most skin issues, including age-related concerns like fine lines and wrinkles.

Is Retinol Suitable For Everyone?

While retinol has a slew of skin-improving benefits, everyone’s skin is different—and sadly, not everyone can tolerate retinol (“We wish that everyone could,” Dr. Henry laments). Those with highly sensitive skin may experience uncomfortable side effects, like redness and peeling. If you notice heightened sensitivity after starting retinol, first, reduce your usage.

Then, we recommend incorporating a calming moisturizer, like Skin Rescuer, into your routine. This lightweight lotion for stressed skin contains skin-friendly ceramides and chamomile extract. It delivers all-day hydration to help balance and comfort aggravated skin while diminishing the visible signs of irritation. When used consistently, it helps strengthen the skin’s natural moisture barrier, leaving it less susceptible to irritating stressors.

If your irritation doesn’t subside even after these changes, retinol may not be for you. “For those people,” Dr. Henry concludes, “we recommend other things, based on whatever they’re looking to treat.”

Next: If your skin is too sensitive for retinol, don’t fret. Check out our article 5 Gentle Retinol Alternatives For Sensitive Skin for non-irritating substitutes to use in your routine.

Orientation message
For the best experience, please turn your device