I’ve been using a trusty retinol serum for several years now, and it’s probably the prized possession of my skin-care routine. If you’re not already using vitamin A, know that it’s revered for its anti-aging, glow-inducing, and acne-fighting prowess—and that’s due to its profound ability to speed up your skin cell turnover process and increase collagen production within skin.

While shopping for one of these MVPs, however, you may have noticed that there are roughly zillions of retinoid-related terms on the back on ingredient labels that are tough to tell apart (like how the heck is retinyl palmitate different from retinol esters?). So to help shed a light on just what exactly these retinol-related ingredients are and what they do, I called in the pros. Know this: Everyone I talked to said that incorporating a vitamin A derivative into your routine is the single best thing that you can do for skin.

“Retinoids are the umbrella term for retinol products, which are all proven to improve skin tone, texture, and pigmentation over time,” explains Jennifer Chwalek, MD, a board-certified dermatologist at Union Square Laser Dermatology in New York City. “Within these categories, there are different concentrations and formulations which consequently affect the strength of the product. For instance, a 0.025 percent cream is not as strong as a .5 percent cream, and a .025 percent cream isn’t as strong as a .025 percent gel.” So yeah… it’s complicated.

To make choosing a retinoid even more difficult, they come in different textures. You can find them in creams, gels, and oils. “In general, gels are usually best for people with oily skin, while creams are better for people with dryer skin—especially forms of retinoids with emollient bases,” says Dr. Chwalek. The good news is that, whichever you choose, your skin will eventually grow to tolerate it better—despite a chance for redness and flakiness in the beginning. To help you decipher the retinol world, keep scrolling for dermatologists’ explanation of vitamin A ingredients, from the most gentle to the most potent.

Retinol ingredients from gentlest to most potent

Retinyl palmitate: The lightest form of retinol is retinyl palmitate, which has to be converted three times within skin, making it the most gentle form of vitamin A. “Retinyl palmitate is an earlier form of retinol, so it must be broken down into retinol, then retinaldehyde, and finally retinoic acid,” explains Dr. Chwalek.

Retinol: The over-the-counter standard, which is a vitamin A derivative gets converted to retinoic acid after it’s absorbed into the skin, according to Rachel Nazarian, MD, a board-certified dermatologist with Schweiger Dermatology Group. “It’s a gentler form that takes longer to see results than some other forms, but effective.” She adds that it’s great for sensitive skin types and those who are new to the retinoid game.

Retinaldehyde: This is the next step after retinol, which only needs to be converted once in the skin to go to work. “The skin can change retinol to retinaldehyde, which is then ultimately turned into retinoid acid,” says Dr. Nazarian. “It’s one step closer to the active molecule, and is better for those who aren’t quite ready for the prescription version, but maybe want a step up from retinol.”

Retinol esters: These are essentially a storage form of retinol in your body, according to Dr. Nazarian, who notes that either applied topically or taken orally, retinol esters can be changed to forms of retinol when needed. “If it’s not used, the body gets rid of it. This form can be stored in the tissues of the eyes, lungs, skin, and spleen, among others.”

Tretinoin: Tretinoins are typically the mildest form of prescription retinoids. Though some tretinoins are available without visiting a derm, most commonly, you’ll find them in in Rx form. “Tretinoin is also known as all-trans-retinoic acid,” explains Dr. Nazarian. “It’s the active molecule. It can come from retinol esters which were in storage, or it can be applied directly on the skin.” According to Dr. Nazarian, it’s best suited for oily-skinned people or those without super sensitive skin, for whom it can cause mild irritation.

Adapalene: If you’re struggling with acne, this retinoid is a good choice. “This is a newer generation of synthetic retinoid that was developed to improve skin and acne,” says Dr. Nazarian. “It’s more chemically stable and has a greater affinity for the receptors that tretinoin targets.” Also, it’s fat-soluble, which, she notes, means it has better absorption, but due to its molecular structure it’s less irritating than tretinoin. “It’s good for people with acne or those who want something strong and have been doing retinol already, but want to take it to the next level,” says Dr. Nazarian.

Tazarotene: This retinoid’s in the same weight-class as adapalene. “It has a different receptor though, and has shown similar effects on the skin but with higher irritation,” explains Dr. Nazarian. “Some studies have shown it to be better for specific acne types than plain tretinoin, and it’s great for oily skin—not for those who are new to retinoids.”

Trifarotene: Trifarotene’s the new retinoid on the skin-care block. “This one binds to less receptors than older options, making it more tolerable and less irritating to the skin,” says Dr. Nazarian. “It had similar results of efficacy for acne—which it was developed for—and likely anti-aging as well.” She notes that it’s ideally a great option for people who have sensitive skin that want prescription-type improvement.

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