Two products that are name-checked across Beauty Secrets videos and get-ready-with-me routines alike: retinol and tretinoin.

While both retinoids appear similar at first glance (they both address pretty much the same most pressing anti-aging and acne skin concerns), there’s a difference between the two. Before you decide to incorporate a retinoid into your routine, consider reading our expert-sourced guide first.

What’s the difference?

The main difference between retinol and tretinoin is the potency. New York City-based board-certified dermatologist Hadley King, MD, explains that all retinoids work by converting to retinoic acid, the active that affects our skin cells. Retinol, she says, requires two conversion steps before turning into retinoic acid, whereas tretinoin is already an active form of retinoic acid and doesn’t need those extra conversion steps. This makes tretinoin the more powerful ingredient between the two.

And because tretinoin is much stronger than retinol, you can only get it through a prescription. Helen He, MD, director of lasers and cosmetic surgery and co-director of the Mount Sinai-Clinique Healthy Skin Dermatology Center, explains that retinol is less potent and can be found in many over-the-counter products.

When to Use Tretinoin

Tretinoin, which promotes skin cell turnover, is best known for treating those pesky breakouts. But it also boosts collagen production and improves the appearance of fine lines, wrinkles, uneven pigmentation, texture, and skin quality. “Out of all topical active ingredients, tretinoin has the strongest level of evidence supporting its benefit for both acne and photoaging,” says Dr. He.

It also comes in two formats, either a cream or a pill. As a topical cream, it’s pretty easy to integrate into a routine, but dermatologists across the board have one piece of advice: “The key is to start slowly and gradually build tolerance,” says Dr. King. She recommends applying tretinoin at night, starting at two to three nights per week and increasing your frequency as tolerated from there.

You’ll want to use just a pea-sized amount for your entire face after you cleanse. Then you’ll want to make sure you lock it in with a moisturizer after, which Dr. He says is a critical step in protecting the skin barrier and reducing irritation. She recommends looking for moisturizers with ingredients like ceramides, glycerin, dimethicone, and panthenol for skin barrier protection and ingredients like centella asiatica to calm any irritation.

You can also consider the “sandwich method” of layering moisturizer, then tretinoin, and locking it in with another layer of moisturizer, she says, or even just mixing it in your moisturizer to help offset any negative side effects.

You should be using SPF every day regardless of your routine, but it’s truly a non-negotiable when using tretinoin because your skin will become more sensitive to the sun. She also recommends being extra careful when using other harsh active ingredients like as alpha hydroxy- and beta hydroxy acids, as well as vitamin C, as it may cause more irritation. Her pro tip: “If using tretinoin at night, it is better to use other active ingredients in the morning,” she says.

But it is very important to note that not everyone will be able to tolerate tretinoin. Tretinoin’s side effects (dryness, irritation, photosensitivity, etc.) are much stronger than retinol's. For sensitive skin, she says it’s best to avoid strong prescription-grade retinoids, as they might disrupt the skin barrier and cause more damage. And if you are pregnant or breastfeeding, Dr. King says to avoid altogether.

When to Use Retinol

Both experts agree that retinol is the better option for those who have sensitive skin or anyone who can’t tolerate tretinoin’s strength. Dr. King adds that thinner skin, such as your neck and décolleté, would tolerate retinol much better than stronger retinoid alternatives like tretinoin, so opt for products with retinol if you’re looking to treat fine lines and sagging in those areas. Dr. He also points out that after menopause, the skin becomes more sensitive and the skin barrier weakens, so she likes to recommend retinol rather than tretinoin for skin aging concerns.

For proper application, she recommends gradually easing into it and starting two to three times weekly and then increasing to nightly as much as your skin can tolerate.

Just like with tretinoin, you need to be cautious when it comes to mixing retinol with other ingredients, especially active ingredients such as alpha hydroxy- and beta hydroxy acids and vitamin C. She adds that retinol is generally applied in the evening as part of your nighttime skincare routine, using only a thin layer in moderation to reduce any risk of irritation. If you’re using a retinol serum, she says to follow up with a moisturizer for added moisture and look for ingredients such as ceramides, glycerin, dimethicone, and panthenol to provide barrier protection. And be sure to use SPF, especially if you use retinol in the daytime.

Similar to tretinoin, those who are pregnant or breastfeeding should avoid using retinol. You should also be careful if you’re dealing with inflammation or have open wounds and infection. As a good rule of thumb, she says that you avoid using it if it compromises the skin barrier.

You should avoid using both tretinoin and retinol at the same time. “Using multiple products with retinoids at the same time will increase the likelihood of skin irritation,” she says. There may be some cases where you might alternate between the two if you can’t tolerate daily use of tretinoin, but always check in with your dermatologist to figure out which retinoid is best for you.

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