If you've ever Googled "best anti-aging skincare ingredients," odds are you've read an article or two on retinoids and retinol. While these two terms are often used interchangeably, the ingredients aren't the same, which makes figuring out which one to use even more confusing.

The main reason retinoids and retinol are often lumped together is that they're related. However, there are a few key differences between the two powerhouse ingredients. To demystify the two once and for all, we tapped two top dermatologists to break down what retinoids do, figure out which one is best for your skin, and learn how to use them in your skincare routine.

Keep scrolling for our complete guide to using retinol vs. retinoid for skin.

What Is a Retinoid?

Retinoids are derivatives of vitamin A that are converted to retinoic acid for skincare products. It's a a blanket term for both over-the-counter retinol and prescription retinoids.

"As we get older, our natural collagen production and cellular turnover processes slow down, which results in the formation of signs of aging like skin laxity, fine lines, wrinkles, and dark spots. Retinoids work by stimulating fibroblasts (the cells responsible for collagen production) deep within the skin," explains Dr. Geeta Yadav, a board-certified dermatologist and founder of Facet Dermatology in Toronto. "This triggers cellular turnover, resulting in fresher, brighter skin with reduced fine lines and wrinkles and a plumper, firmer appearance." And since retinoids accelerate collagen production and cellular turnover, they can also help reduce acne.

What Is Retinol?

Retinol typically refers to a type of retinoid used in over-the-counter skincare products. The big difference is the molecular structure of retinol. "It's a precursor molecule to retinoic acid. In the skin, it is converted into retinaldehyde which then becomes retinoic acid — the molecule which exerts its positive effects on the skin," says Dr. Brian Hibler of Schweiger Dermatology Group in New York City.

Because retinol requires the extra step of converting to retinoic acid, it's less potent than other retinoids. However, this can benefit those whose skin can handle high concentrations of vitamin A. "For your skin to process vitamin A and its benefits, it needs to convert the retinol into retinoic acid before it can be used," Dr. Yadav says. "This makes over-the-counter retinol less effective but more tolerable than the prescription version."

Who Should (And Shouldn't) Use Retinoids and Retinol

A major reason why retinoids and retinol are highly recommended by dermatologists is because most skin types can tolerate them. What will vary, however, is the vitamin A derivative and concentration you use.

Still, Dr. Yadav says that certain skin types should proceed with caution and consult a dermatologist before incorporating over-the-counter retinol into their skincare routine. "Highly sensitive skin easily sensitized complexions, and very dry skin types should avoid vitamin A derivatives like retinoic acid and retinol," he tells us.

Those who are pregnant or breastfeeding should also avoid using retinoids or retinol, adds Dr. Hibler. The Food and Drug Administration (FDA) has put retinoids in pregnancy category C, which means they can cause fetal loss and malformations, so dermatologists recommend not using them out of an abundance of caution.

Side Effects of Retinoids and Retinol

The side effects of retinoids are so infamous, they even have a name — there are entire Reddit threads dedicated to tips for overcoming the "retinoid uglies."

The "retinoid uglies" can include peeling, flaking, redness, irritation, sensitivity, and dryness. However, it's possible to avoid these side effects by slowly introducing the ingredient into your routine to allow your skin to build up a tolerance.

How to Use Retinoids and Retinol

A little product goes a long way: A pea-sized amount of retinol or retinoid is all you need for your skin to reap its benefits. "If too much redness, irritation, or dryness occurs, then take a few days off and use a smaller amount of the topical retinoid and slowly work it back into your routine," Dr. Hibler says.

"Always start with a low strength and use it only a few times a week," suggests Dr. Hibler. "Apply a moisturizer immediately after. Increase the strength and frequency slowly. Your skin will tell you if you are using it too much or too often."

Slow and steady is important when using a retinoid or retinol in your routine, but when you use them is also important. Nighttime is typically best for using the ingredient as that's when the skin repairs itself, plus, vitamin A can cause sun sensitivity.

While the ingredient is best used before moisturizer, when you're just starting out, you can moisturize beforehand to buffer the skin and prevent irritation. "Applying a layer of moisturizer to the skin before applying your retinoid can also make the adjustment period more comfortable," says Dr. Yadav. "Once your skin becomes less reactive to the retinoids, you can increase your application to twice weekly. Eventually, you'll be able to work your way up to a nightly application." That being said, it's typically easier for the skin to acclimate to retinol because it's not as strong as retinoids.

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Ingredients to Avoid When Using Retinoids and Retinol

While almost anyone can use retinoic acid, not every skincare ingredient plays nice with it. Dr. Hibler says to avoid exfoliants that contain BHAs (like salicylic acid) or AHAs (like glycolic acid) because they can increase the absorption of the retinoid or retinol and thus cause more sensitivity.

"Using them [exfoliants and retinoids/retinol] simultaneously will strip your skin's moisture barrier, causing a phenomenon known as over-exfoliation,' Dr. Yadav adds. "That can be very uncomfortable and result in painful, tender skin for several weeks; when skin is over-exfoliated, you must discontinue use of all skincare products, even most cleansers." The dermatologist says that many doctors will even recommend just cleansing with water during this time to avoid irritation.

The Final Takeaway

If you're looking to combat — or even prevent — signs of aging, incorporating retinol and retinoid into your skincare routine is your best bet. When deciding whether to use one over the other, keep strength in mind and whether you've ever used the ingredients before. Retinol is a gentler type of retinoid and may be a good option if you're new to the whole anti-aging skincare game or if you have sensitive skin, dry skin, or a skin condition. Still unsure of whether to use retinol or a retinoid? Speak to your dermatologist. They'll be able to analyze your skin type and concerns and determine which is right for you.